ArticlePDF Available

Appetitive and aversive motivation in depression: The temporal dynamics of task-elicited asymmetries in alpha oscillations

Authors:

Abstract and Figures

The capability model of alpha asymmetries posits that state emotional manipulations are a more powerful detector of depression-related motivational deficits than alpha activity at rest. The present study used a time-frequency approach to investigate the temporal dynamics of event-related changes in alpha power during passive viewing of emotional pictures in individuals with dysphoria (n = 23) and in individuals without dysphoria (n = 24). In the whole group, the processing of pleasant and unpleasant compared to neutral pictures was associated with a decrease in event-related alpha power (i.e., alpha desynchronization) at centro-parietal and parietal scalp sites in the 538–1400 ms post-stimulus. The group with dysphoria revealed a smaller alpha desynchronization than the group without dysphoria in response to pleasant, but not neutral and unpleasant, stimuli at frontal, fronto-central and centro-parietal sites. Interestingly, at central and centro-parietal scalp sites, the difference between groups in response to pleasant stimuli was lateralized to the right hemisphere, whereas no clear lateralization was observed at frontal and fronto-central scalp sites. These findings suggest that decreased cortical activity (i.e., reduced alpha desynchronization) in a network involving bilateral frontal and right-lateralized parietal regions may provide a specific measure of deficits in approach-related motivation in depression.
This content is subject to copyright. Terms and conditions apply.
1
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
Appetitive and aversive motivation
in depression: The temporal
dynamics of task-elicited
asymmetries in alpha oscillations
Simone Messerotti Benvenuti
1*, Giulia Buodo1, Rocco Mennella2, Elisa Dal Bò1 &
Daniela Palomba1
The capability model of alpha asymmetries posits that state emotional manipulations are a more
powerful detector of depression-related motivational decits than alpha activity at rest. The present
study used a time-frequency approach to investigate the temporal dynamics of event-related changes
in alpha power during passive viewing of emotional pictures in individuals with dysphoria (n = 23) and in
individuals without dysphoria (n = 24). In the whole group, the processing of pleasant and unpleasant
compared to neutral pictures was associated with a decrease in event-related alpha power (i.e., alpha
desynchronization) at centro-parietal and parietal scalp sites in the 538–1400 ms post-stimulus. The
group with dysphoria revealed a smaller alpha desynchronization than the group without dysphoria
in response to pleasant, but not neutral and unpleasant, stimuli at frontal, fronto-central and centro-
parietal sites. Interestingly, at central and centro-parietal scalp sites, the dierence between groups
in response to pleasant stimuli was lateralized to the right hemisphere, whereas no clear lateralization
was observed at frontal and fronto-central scalp sites. These ndings suggest that decreased cortical
activity (i.e., reduced alpha desynchronization) in a network involving bilateral frontal and right-
lateralized parietal regions may provide a specic measure of decits in approach-related motivation in
depression.
Depression is characterized by excessive and persistent negative mood, and/or by anhedonia and loss of pleas-
ure in daily activities1. It has been proposed that both emergence and maintenance of depressive symptoms are
accounted for by a preferential processing bias for mood-congruent (i.e., negative) information (for a review see
Clark & Beck2). Such bias is supposed to produce a dominance of negative or threat-related thoughts, images and
interpretations, in line with the idea that negative mood potentiates like-valenced or matching emotions3, known
as the negative potentiation hypothesis.
Despite the empirical support to this conceptualization46, recent evidence suggests, on the contrary, that
depressive symptoms emerge mostly as a consequence of reduced emotional response to positively valenced
and rewarding stimuli7,8, possibly indicating a dysregulation of the approach-related motivational system in
the brain9,10. Importantly, reduced approach-related motivation constitutes an important risk factor for clinical
depression11 and – despite its scarce consideration in clinical practice – it may account for core symptoms such as
anhedonia, apathy and loss of interests (for a review see Admon & Pizzagalli12). is model, known as the positive
attenuation hypothesis, has been recently extended by a third alternative that postulates that depression is char-
acterized by blunted reactivity to all emotional stimuli regardless of their valence, the so-called emotional context
insensitivity (ECI)13,14. Specically, the ECI model holds that individuals with depression exhibit reduced reactiv-
ity in response to both pleasant and, in contrast with the negative potentiation hypothesis, unpleasant stimuli, as
a result of underactivation of the appetitive and the defensive motivational systems, respectively.
Reduced approach-related motivation in subclinical15,16 and clinical depression17,18, as well as in euthymic
participants with a history of depression19,20, has been associated with hypoactivity of the le frontal lobe com-
pared to the right. ese ndings support a renowned conceptual model which proposed that le frontal activity
1Department of General Psychology, University of Padua, Padua, Italy. 2Laboratoire de neurosciences cognitives,
Département d’études cognitives, École normale supérieure, INSERM, PSL Research University, 75005, Paris,
France. *email: simone.messerotti@unipd.it
OPEN
Content courtesy of Springer Nature, terms of use apply. Rights reserved
2
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
subtends the propensity to approach or engage a stimulus, whether reduced le vs. right frontal activity indi-
cates a reduction in approach behaviors and increased withdrawal motivation2124. Unbalanced cortical activity
between the frontal areas of the two hemispheres is typically measured as asymmetry in the alpha band, a brain
rhythm associated with cortical inhibition25. Accordingly, a recent EEG study conrmed that alpha asymmetry
measured from the scalp correlated with asymmetry in the activation of lateral mid-frontal regions of the brain,
and that participants with a history of depressive episodes were characterized by less le relative to right cortical
activity in these regions26.
So far, the vast majority of studies on frontal alpha asymmetry in depression have investigated reduced
approach-related motivation at rest. is is consistent with a dispositional model of motivation and aective
style, which proposes that individuals have a trait-like tendency to respond with either approach or withdrawal,
irrespective of the specic demands of the situation23. Nonetheless, inconsistent results have emerged, raising
criticisms about the eective value of resting frontal alpha asymmetry as a potential biomarker for depression
(for a recent meta-analysis see van der Vinne et al.27). Following these concerns, a capability model has been
proposed, which states that individuals dier in their emotion regulatory abilities in situations with specic emo-
tional charges28. In other words, reduced approach-related motivation in depression is thought to be more evident
in response to emotional stimuli than at rest, since the emotional demands of the context highlight the motiva-
tional decit, and reduce undesirable variance associated with resting states25,28,29.
To date, only few studies have started investigating alpha asymmetry in depression in emotion- or
reward-related tasks9,2931. Moreover, two methodological shortcomings ought to be mentioned. First, EEG activ-
ity has typically been averaged over several seconds, providing no information regarding the timecourse of the
response to emotional stimuli. is is surprising considering that emotional responding and regulation occur
within a few hundred of millisecond, and considering that alpha asymmetry has been reported to burst tran-
siently also at rest32. Furthermore, recent studies have analyzed alpha activity only at anterior scalp sites, even if
asymmetry in the alpha band in depression has been reported also at posterior scalp sites, despite some excep-
tion33. In particular, depression (current or remitted) and familiarity for depression are characterized by a right
temporo-parietal dysfunction, as indicated by increased right relative to le parietal alpha activity19,33,34. Decreased
right parietal activity is thought to reect reduced arousal and impaired processing of emotional stimuli33,3537,
and may thus concur to emotional dysregulation in depression.
A time-frequency analysis of the EEG response to emotional stimuli allows to overcome most of these limita-
tions. Importantly, frontal alpha response to emotional stimuli can be evaluated over time, overcoming the “static
picture” provided by conventional fast Fourier transform (FFT) spectral analysis based on averaging procedures.
Interestingly, this method has been proven successful in detecting transient motivational responses to phobic
pictures in specic phobia38, as indicated by alpha power at frontal sites. More specically, the time-frequency
approach allows to assess how depression-related motivational disposition aects alpha power in response to
emotional stimuli with an excellent temporal resolution (in the millisecond range).
e goal of the present study was to investigate motivational decits in depression through the analysis of
the time-frequency changes in response to emotional stimuli from the International Aective Picture System
(IAPS) library39, according to the capability model of alpha asymmetries. So far, aective pictures processing in
a passive viewing task has been assessed mostly with regard to distinct components of the event-related poten-
tials (ERPs). In particular, compared with low-arousing neutral stimuli, high-arousing pleasant and unpleasant
stimuli typically elicit larger P3 and late positive potential (LPP) amplitudes over the centro-parietal regions in
the 300–700 ms time window, which are thought to reect attentional processing of emotional stimuli4042. In the
present study, pictures (pleasant, neutral and unpleasant) were selected to elicit robust P3/LPP complex, serving
as an experimental manipulation check. e group with dysphoria was expected to show a smaller decrease in
event-related alpha power (i.e., a reduced alpha desynchronization) in the le frontal and the right posterior
regions in response to pleasant (but not neutral and unpleasant) pictures compared to controls, as a correlate of
reduced approach-related motivation. Given that the negative potentiation model and the ECI model make two
opposite predictions with respect to depression-related emotional reactivity in response to negative stimuli, no a
priori hypothesis was formulated regarding the direction of changes in event-related alpha power in response to
unpleasant pictures.
Methods
Participants. e method used to recruit participants was based on that described in a previous study by
Messerotti Benvenuti et al.10 Specically, in order to preliminary identify participants with dysphoria, 197 under-
graduate students from the University of Padua completed an online version of the Beck Depression Inventory-II
(BDI-II43; Italian version by Ghisi et al.44). e BDI-II is a reliable and valid self-report questionnaire that evalu-
ates the severity of symptoms of depression in the past two weeks. Answers are given on a four-point (0–3) Likert
scale and scores range from 0 to 63, with the higher scores indicating more severe depressive symptoms. In the
Italian version, a score of 12 has been reported as the optimal cut-o score to discriminate individuals with and
without depressive symptoms44. Participants scoring equal to or greater than 12 on the online version of BDI-II
(n = 77) were invited to participate in the study and were administered a paper-and-pencil version of the BDI-II
and the mood episode module (module A) of the Structured Clinical Interview for the DSM-IV Axis I (SCID-I45;
Italian version by Mazzi et al.46) approximately one week aer the initial screening. e module A of the SCID-I
was administered to conrm the presence of dysphoria and to exclude individuals with major depression, dys-
thymia or bipolar disorder. e module A of the SCID-I was administered by a trained psychologist who had
previous experience with administering structured clinical interviews. Twenty-three participants [22 females and
1 male; age, mean (M) = 21.9, standard deviation (SD) = 2.2; BDI-II score, M = 17.3, SD = 4.4], who scored equal
to or greater than 12 on both versions of the BDI-II and had at least two current depressive symptoms, at least two
weeks in duration, without meeting the diagnostic criteria for major depression, dysthymia or bipolar disorder,
Content courtesy of Springer Nature, terms of use apply. Rights reserved
3
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
were assigned to the group with dysphoria. In order to ensure separation between groups with and without dys-
phoria, we selected 24 individuals without dysphoria [23 female and 1 male; age, M = 22.0, SD = 1.9; BDI-II score,
M = 2.6, SD = 1.9] with an online BDI-II score 8 (corresponding to the 45° percentile) and conrmed in the
subsequent administration of the paper-and-pencil version of the BDI-II. Participants who scored between 9 and
11 either on the online or the paper-and-pencil BDI-II, or had at least one depressive symptom as evaluated by
the SCID-I interview were excluded from the present study.
All the participants enrolled in the present study met the following inclusion criteria as assessed by an ad-hoc
interview: 1) being medically healthy, and 2) being free of psychotropic medications. With respect to demo-
graphic variables, the two groups (with dysphoria, without dysphoria) did not dier in terms of gender (Fisher’s
exact test, p = 0.99) and age, F(1,45) = 0.05, p = 0.83, η2p = 0.00. e group with dysphoria showed signicantly
higher BDI-II scores than the group without dysphoria, F(1,45) = 226.69, p < 0.001, η2p = 0.83.
Ethics statement and informed consent. e present study was conducted with the adequate under-
standing and written consent of the participants in accordance with the Declaration of Helsinki. e study was
approved by the local Ethics Committee, University of Padua (prot. No. 2101), and written informed consent was
obtained from each participant enrolled in the study.
Stimuli and procedure. Participants were presented seventy-two pictures selected from the IAPS39, divided
into three categories: 24 pleasant (e.g., erotic scenes, sports), 24 neutral (e.g., neutral faces, household objects),
and 24 unpleasant (e.g., attacking humans and animals). e pictures were selected on the basis of their standard-
ized ratings of aective arousal and valence. e mean (SD) normative valence ratings were 7.0 (0.5), 4.9 (0.3) and
2.9 (0.7) for pleasant, neutral and unpleasant pictures, respectively. e mean (SD) normative arousal ratings were
6.5 (0.4), 2.9 (0.7) and 6.5 (0.5) for pleasant, neutral and unpleasant pictures, respectively. Pleasant and unpleasant
stimuli were matched for arousal (p = 0.92). e IAPS picture numbers were 1050, 1114, 1120, 1300, 1302, 1930,
1932, 3500, 4611, 4647, 4651, 4652, 4660, 4664, 4670, 4680, 4683, 4690, 4695, 4810, 6200, 6210, 6230, 6242, 6243,
6244, 6250, 6260, 6312, 6313, 6370, 6510, 6540, 6550, 6560, 7000, 7002, 7004, 7009, 7010, 7020, 7035, 7036, 7041,
7050, 7056, 7059, 7130, 7175, 7224, 7233, 7242, 7491, 7500, 7547, 7560, 7595, 7700, 7950, 8030, 8031, 8034, 8080,
8161, 8180, 8185, 8186, 8200, 8370, 8400, 8490, 9425.
Pictures were presented for 6,000 ms each in a semi-randomized sequence (i.e., no more than one stimulus
in the same emotional condition had to be shown consecutively). Each picture was preceded by a 3,000-ms gray
interval with a white xation-cross placed centrally on the screen. In order to ensure that participants processed
each pictures content, they were required to look at the central xation-cross and keep their gaze on the center of
the screen. An acoustic startle probe was presented at one of four intervals (i.e., 300, 1500, 3500 or 4500 ms aer
picture onset) on each trial, thus providing 6 data points for each time condition within each emotional category.
e data analysis did not include trials on which a startle probe was delivered at 300 ms aer pictures onset.
erefore, six stimuli for each emotional condition were excluded from the analysis. e startle reex (and heart
rate) data are not presented here. e inter-stimulus interval was randomly varied between 6,000 and 8,000 ms.
e task was presented by a Pentium IV computer on a 19-in. computer screen, using E-prime 2.0 presentation
soware (Psychology Soware Tools, Pittsburgh, PA, USA).
According to the procedure reported in a previous study by Messerotti Benvenuti et al.10, upon arrival at the
laboratory, the participants were rst administered a paper-and-pencil version of the BDI-II and the mood epi-
sode module (module A) of the SCID-I interview. en, participants were seated 100 cm away from the computer
monitor, in a dimly lit, sound-attenuated room. Aer the sensors were attached, six practice trials including two
pleasant, two neutral, and two unpleasant pictures were provided. en, each participant performed the emo-
tional passive viewing task.
At the end of the passive viewing task, 36 pictures (12 for each emotional category) were presented again
in a randomized sequence, and ratings of emotional valence and arousal were obtained using a two comput-
erized 9-point Self-Assessment Manikin (SAM) scales47. e SAM uses manikin gures for both valence and
arousal dimensions. On the valence dimension, the SAM gures range from a frowning-unhappy gure (1, very
unpleasant) to a smiling-happy gure (9, very pleasant). On the arousal dimension, the SAM gures range from
a static-eyes-closed gure (1, very calm) to an active-wide-eyed gure (9, very aroused). Following completion of
the self-evaluation of emotional valence and arousal, the participants were fully debriefed. e entire procedure
lasted approximately 90 min.
Electroencephalographic recordings. e EEG was recorded from 32 scalp sites using an elastic cap with
tin electrodes (Waveguard EEG cap, ANT Neuro, Enschede, Netherlands). e EEG sites were FP1, FPz, FP2, F7,
F3, Fz, F4, F8, FC5, FC1, FC2, FC6, T7, C3, Cz, C4, T8, CP5, CP1, CP2, CP6, P7, P3, Pz, P4, P8, POz, O1, Oz,
O2, A1 (le mastoid) and A2 (right mastoid), all referenced online to CPz. To control for eye movements and eye
blinks, vertical and horizontal electrooculograms (EOGs) were recorded using bipolar montages. Electrode pairs
were placed at the supra- and suborbital right eye and at the external canthi of the eyes. Electrode impedance
was kept below 10 k. e EEG and EOG signals were amplied with eego amplier (ANT Neuro, Enschede,
Netherlands), bandpass ltered (0.3–40 Hz), and digitized at 1000 Hz.
Data preprocessing. e EEG signal was downsampled to 500 Hz and re-referenced oine to a linked
mastoids montage. e EEG was ltered oine with a low-pass lter at 30 Hz and manually corrected for blink
artifacts using independent component analysis (ICA) as implemented in EEGLAB48. Further processing was
conducted in Brainstorm49. e EEG was then segmented into 4,000 epochs, from 2,000 ms before to 2,000 ms
aer stimulus onset, in order to prevent boundary eects. Each epoch was baseline-corrected by subtracting the
mean pre-stimulus voltage between 252 ms and 52 ms. en, segments containing residual artifacts exceeding
Content courtesy of Springer Nature, terms of use apply. Rights reserved
4
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
±70 μV (peak-to-peak) were excluded. e artifact rejection led to an average (SD) acceptance for the ERP and
for the time-frequency analyses of 17.0 (1.2) pleasant trials, 17.0 (1.1) neutral trials and 17.1 (1.0) unpleasant trials
in the group with dysphoria, and of 16.6 (1.1) pleasant trials, 16.8 (1.2) neutral trials and 17.0 (0.9) unpleasant
trials in the group without dysphoria. No signicant dierences between groups or among emotional conditions
in the average acceptance of pleasant, neutral and unpleasant trials were noted (all ps > 0.25).
Event-related potentials (ERPs). ERPs were calculated by averaging EEG epochs in the time domain
separately for each participant and emotional condition.
Time-frequency analysis. With respect to the time-frequency analysis, Morlet wavelet transformation on
individual trials was applied for each 1 Hz frequency bin between 1 and 20 Hz, using a mother wavelet at 1 Hz with
2-s time resolution (as calculated by the full width at half maximum; FWHM). Time-frequency decompositions
were then averaged for each subject and emotional condition, and the event-related spectral perturbation (ERSP)
was computed as the change in power expressed in decibels (dB) relative to the baseline (500 to 52 ms) in each
frequency bin at each time point. en, data were grand averaged across participants with dysphoria and across
participants without dysphoria for each emotional condition.
Statistical analysis. Self-report data. Separate mixed analyses of variance (ANOVAs) with Group (with
dysphoria, without dysphoria) as a between-subjects factor, and Category (pleasant, neutral, unpleasant) as a
within-subjects factor, were conducted on self-reported valence and arousal. e corrected p-values for eects
involving within-subjects variables with more than two levels are reported together with the Greenhouse-Geisser
epsilon (ε) and the uncorrected degrees of freedom. Signicant main eects and/or interactions (p < 0.05) were
followed by Tukey HSD post-hoc tests in order to correct for multiple comparisons. Cohens d (absolute value) for
relevant comparisons was calculated as a measure of the eect size. All eect sizes, corrected for the sample bias50,
are reported with 95% condence intervals (CIs) and were considered signicant if the CIs did not overlap zero.
EEG data: general method. In order to perform statistical analysis on EEG data, a cluster-based approach has
been conducted to control over the type I error rate arising from multiple comparisons across electrodes and time
points51. Statistical tests were run across electrodes and time points; the resulting values were thresholded and
the dierences among emotional conditions or groups were shued pseudo-randomly 2000 times. e maximal
cluster-level statistics (i.e., the sum of values across contiguously signicant electrodes and time points at the
threshold level) were extracted for each shue to compute a ‘null’ distribution of eect sizes. For each signicant
cluster in the original (non-shued) data, it was computed the proportion of clusters in the null distribution
whose statistics exceeded the one obtained for the cluster in question, corresponding to its cluster-corrected
p-value. Clusters with a pcorr < 0.05 were considered statistically signicant.
ERP data: Repeated measures ANOVAs over all electrodes and time-points in the 100 to 700 ms interval
were employed to test dierences in ERP amplitudes among emotional conditions (Category: pleasant, neutral,
unpleasant), with the group variable collapsed. An initial conservative alpha of 0.001 was employed to threshold
the matrices due to the expected large eect of emotional category on P3/LPP complex, in order to highlight the
electrodes and time points where the dierence was more prominent (note that this value does not aect the false
alarm rate of the statistical test at the cluster-level51).
When the time window was identied, a second cluster-based analysis was run to test the dierences between
groups within each emotion category. In this analysis, a two-tailed unpaired t-test on the ERP amplitude averaged
over the signicant time window was conducted across electrodes for each emotional condition.
Time-frequency data: A similar cluster-based analysis was conducted on event-related alpha power (8–13 Hz),
with a 100–1400 ms time window and a pthresh = 0.05. en, in order to perform analysis at the group level, the
same cluster-based approach (statistic = one-tailed unpaired t-test) on the event-related alpha power averaged
over the signicant time points was conducted across electrodes for each emotional category. One-tailed t-test
was used based on an a priori hypothesis about the direction of the dierence between groups in event-related
alpha power in response to pleasant stimuli.
In order to control for the specicity of the eects on alpha, the same statistical approach was conducted on
event-related changes in delta (1–3 Hz), theta (4–7 Hz), and beta (14–20 Hz) power, using a two-tailed unpaired
t-test.
Results
Self-report data. e mixed ANOVA on valence ratings yielded a signicant main eect for Category, F(2,90) =
280.76, p < 0.001, ε = 0.85, ηp2 = 0.86. Unpleasant pictures were evaluated as signicantly more unpleasant than
neutral (p < 0.001; d = 3.36, 95% CI = 2.73, 3.99) and pleasant (p < 0.001; d = 4.11, 95% CI = 3.40, 4.82) pictures.
Pleasant stimuli were rated as signicantly more pleasant than neutral ones (p < 0.001; d = 1.49, 95% CI = 1.04,
1.95). No signicant main eect for Group or Group × Category interaction was found (all ps > 0.11). Similarly,
the ANOVA on arousal ratings revealed a signicant main eect for Category F(2,90) = 114.89, p < 0.001, ε = 0.83,
ηp2 = 0.72. Specically, arousal ratings were higher for both pleasant and unpleasant pictures compared to neutral
ones (pleasant vs. neutral: p < 0.001; d = 1.46, 95% CI = 1.01, 1.92; unpleasant vs. neutral: p < 0.001; d = 1.96,
95% CI = 1.47, 2.46). Unpleasant pictures were rated as more arousing than pleasant stimuli (p < 0.001; d = 0.54,
95% CI = 0.12, 0.95). However, it is important to note that this eect was driven by participants with dysphoria
(d = 0.84, 95% CI = 0.24, 1.44) instead of controls, in which the eect size of the dierence between the pleas-
ant and unpleasant stimuli was small (d = 0.31, 95% CI = 0.26, 0.88). No signicant main eect for Group
or Group × Category interaction was found (all ps > 0.18). e descriptive statistics of self-report measures are
reported in Table1.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
5
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
ERP data. Dierences among emotional categories. e cluster-based analysis on ERP data showed a sig-
nicant positive fronto-centro-parieto-occipital cluster (cluster F-valuemax = 63009.06, pcorr < 0.001, time win-
dow = 400–604 ms, electrodes = F3, Fz, F4, FC5, FC1, FC2, FC6, T7, C3, Cz, C4, T8, CP5, CP1, CP2, CP6, P7, P3,
PZ, P4, P8, POz, O1, Oz, O2), as shown in Fig.1 (panel a). Specically, the whole group revealed a signicantly
larger P3/LPP complex in response to pleasant and unpleasant stimuli than neutral ones (all ps < 0.001; Fig.1,
panels b,c), especially at central, centro-parietal and parietal scalp sites (Fig.1, panel a).
Dierences between groups for each emotional category. Unpaired t-test conducted on the P3/LPP amplitude
averaged over the 400–604 ms time window, where the eect of emotion emerged in the previous analysis, did not
reveal any signicant cluster for the dierence between the groups within each emotional condition.
Time-frequency data. Differences among emotional categories in event-related alpha power. In
the whole group, the cluster-based analysis on event-related alpha power revealed a significant positive
centro-parieto-occipital cluster (cluster F-valuemax = 37097.61, pcorr = 0.01, time window = 538–1400 ms, elec-
trodes = FC5, T7, C3, C4, T8, CP5, CP1, CP2, CP6, P7, P3, Pz, P4, P8, POz, O1, Oz, O2), as shown in Fig.2 (panel
Self-report
measure
Group with dysphoria (n = 23) Group without dysphoria (n = 24)
Pleasant Neutral Unpleasant Pleasant Neutral Unpleasant
Valence 6.3 (1.0) 5.3 (0.5) 2.7 (1.2) 6.7 (0.8) 5.3 (0.7) 2.4 (0.8)
Arousal 5.1 (1.4) 2.8 (1.7) 6.4 (1.5) 4.9 (1.8) 2.6 (1.5) 5.5 (1.8)
Table 1. Ratings of each self-report measure in the group with dysphoria and in the group without dysphoria.
Note. Data are M (SD).
Figure 1. (Panel a) Topography of the mean ERP amplitude (μV) averaged over the signicant time points
(400–604 ms time window) for pleasant, neutral and unpleasant conditions. (Panel b) Time course of grand-
average ERP waveforms averaged over the signicant electrodes for pleasant (red line), neutral (grey line) and
unpleasant (light blue line) conditions. Shaded areas represent ± standard error of the mean (SEM); the colored
frame represents the signicant time window (400–604 ms). (Panel c) Mean ERP amplitude of each participant
averaged over the signicant electrodes and time points for pleasant, neutral and unpleasant conditions. Each
circle represents one participant; colored frames represent the mean ERP amplitude across all participants and
the solid black lines represent ± SEM. ***p < 0.001.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
6
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
a). In particular, reduced event-related alpha power was evident in response to pleasant and unpleasant stimuli
compared to neutral ones (all ps < 0.05), as shown in Fig.2 (panels b,c).
Dierences between groups in event-related alpha power for each emotional category. With respect to the dier-
ences between groups for each emotional condition in the 538–1400 ms time window, the cluster-based analysis
on event-related alpha power showed a signicant negative fronto-centro-parietal cluster in the pleasant con-
dition (cluster t-valuemax = 29.24, pcorr = 0.02, electrodes = FP1, FPz, FP2, F7, F3, Fz, F4, F8, FC5, FC1, FC2,
FC6, C4, CP6), as shown in Fig.3 (panel a). Specically, the group without dysphoria revealed a larger decrease
in event-related alpha power in response to pleasant stimuli than the group with dysphoria (Fig.3, panels b,c).
It is intriguing to note that at central and centro-parietal scalp sites, the dierence between groups in response
to pleasant stimuli was lateralized to the right hemisphere, whereas no lateralization was observed at frontal and
fronto-central scalp sites (Fig.3, panel a). It is also worth noting that no signicant dierences between groups in
response to neutral and unpleasant stimuli were noted (Fig.3, panel b).
Dierences between groups in event-related delta, theta and beta power for each emotional category. Unpaired
t-test conducted on event-related power of other EEG frequency bands averaged over the signicant time win-
dows (delta: 100–972 ms; theta: 186–724 ms; beta: 750–1064 ms), where the eect of emotion emerged in the
ANOVAs, did not reveal any signicant cluster for the dierence between the groups within each emotional
condition.
Discussion
e present study investigated motivational decits in depression during the passive viewing of emotional pic-
tures, according to the capability model of alpha asymmetries. A time-frequency approach was used to examine
event-related changes in alpha power in individuals with dysphoria vs. healthy controls with high temporal res-
olution. Based on previous literature reporting reduced approach-related motivation in depression1012,33,35,37,
individuals with dysphoria were expected to show less alpha desynchronization in the le frontal and the right
posterior regions in response to pleasant pictures compared to controls.
Figure 2. (Panel a) Topography of the mean event-related alpha power (dB) averaged over the signicant time
points (538–1400 ms time window) for pleasant, neutral and unpleasant conditions. (Panel b) Time course of
grand-average event-related alpha power averaged over the signicant electrodes for pleasant (red line), neutral
(grey line) and unpleasant (light blue line) conditions. Shaded areas represent ± standard error of the mean
(SEM); the colored frame represents the signicant time window (538–1400 ms). (Panel c) Mean event-related
alpha power of each participant averaged over the signicant electrodes and time points for pleasant, neutral
and unpleasant conditions. Each circle represents one participant; colored frames represent the mean event-
related alpha power across all participants and the solid black lines represent ± SEM. *p < 0.05; **p < 0.01.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
7
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
In line with our hypothesis, individuals with dysphoria showed less alpha desynchronization in response to
pleasant stimuli than the group without dysphoria. e eect was evident between 538–1400 ms post-stimulus
and was seen at frontal, fronto-central, central and centro-parietal scalp sites. It is important to note that
event-related changes in alpha power in response to unpleasant and neutral stimuli were comparable between the
two groups. In addition, no dierence between groups emerged for delta, theta and beta power, indicating that the
present ndings were specic for alpha power. Accordingly, these results suggest that depression is characterized
by reduced activation of the appetitive (approach) motivational system8,10,11.
However, only partially in line with our hypothesis, the dierence between groups in response to pleasant
stimuli was lateralized to the right hemisphere at centro-parietal scalp sites, whereas no evident lateralization
was observed at frontal and fronto-central scalp sites. e present result reects a reduced cortical activation
over bilateral anterior and right-lateralized centro-parietal regions during the processing of pleasant stimuli in
individuals with dysphoria as compared to controls. In turn, this suggests that a decreased cortical activation in a
network involving bilateral frontal and right-lateralized parietal regions may provide a specic measure of de-
cits in the Approach Motivation construct within the Positive Valence Systems proposed by the NIMH Research
Domain Criteria (RDoC)52.
Along the same line of reasoning, the present results provide support for the capability model of individual
dierences in alpha asymmetry at posterior, but not at anterior scalp sites. It can be suggested that lateralized
event-related alpha power at central and centro-parietal scalp sites is more likely to reect depression-related de-
cits in the processing of motivationally relevant stimuli than frontal alpha asymmetry. However, the latter result
is at odds with ndings of previous studies reporting that frontal alpha asymmetry discriminates individuals with
depression from healthy controls in approach-related and withdrawal-related conditions29,30. An explanation for
Figure 3. (Panel a) Topography of the mean dierence between groups in event-related alpha power (dB; group
without dysphoria minus group with dysphoria) averaged over the signicant time points (538–1400 ms time
window) for the pleasant condition. (Panel b) Time course of grand-average event-related alpha power averaged
over the signicant electrodes for pleasant, neutral and unpleasant conditions in the group with dysphoria (solid
line) and in the group without dysphoria (dashed line). Shaded areas represent ± standard error of the mean
(SEM); the colored frame represents the signicant time window (538–1400 ms). (Panel c) Mean event-related
alpha power of each participant in the group with dysphoria and in the group without dysphoria (i.e., controls)
averaged over the signicant electrodes and time points for the pleasant condition. Each circle represents one
participant; theframes represent the mean event-related alpha power across all participants in the group with
dysphoria and in the group without dysphoria and the solid black lines represent ± SEM. *p < 0.05.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
8
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
the discrepant ndings may lie in the fact that changes in event-related alpha power were examined in the milli-
second range, whereas other studies typically computed alpha activity (and its asymmetries) over longer periods
of time29. It is worth noting that the eect reported here was robust because the cluster-based analysis allows to
correct for multiple comparisons across electrodes and time points.
In the whole group, the present study showed greater alpha desynchronization in response to high-arousing
emotional (pleasant and unpleasant) compared to low-arousing neutral stimuli in the 538–1400 ms time win-
dow, suggesting that decrease in event-related alpha power may reect arousal dimension. is interpretation
is consistent with recent ndings showing a greater alpha desynchronization in response to high-arousing (i.e.,
erotic) rather than low-arousing (i.e., romantic) pleasant pictures between 600–1000 ms post-stimulus at anterior
and posterior scalp sites53. Similarly, a decrease in event-related alpha power has been reported to be associated
with higher arousal for both pleasant and unpleasant stimuli, with the largest alpha desynchronization occurring
in response to erotic and mutilation pictures54. It has to be noted that results regarding changes in event-related
alpha power in response to emotional stimuli have also reported null ndings55 or opposite eects (alpha syn-
chronization56,57). However, these studies varied remarkably in terms of critical methodological aspects such as
central or lateralized presentation of the stimuli, data analysis technique to calculate alpha oscillations, limited
number of sensors and picture exposure duration.
In addition, in the whole group ERP results showed the presence of the P3/LPP complex, with larger ampli-
tude occurring in response to pleasant and unpleasant than neutral stimuli at centro-parietal and parietal scalp
sites in the 400–604 ms time window. Replicating P3/LPP modulations to high-arousing emotional stimuli com-
pared to low-arousing neutral stimuli with predicted polarity, topography and latency conrmed the eectiveness
of the experimental manipulation. It is well-established that P3/LPP complex reects continued allocation of
attention to emotional stimuli and facilitated processing and encoding of motivationally relevant stimuli (for a
review, see Lang & Bradley40). Our data are in line with those of previous studies showing that LPP and alpha
desynchronization may reect similar processes54. However, it is worth noting that the group with dysphoria
and the group without did not dier in P3/LPP amplitude in none of the three emotional conditions. In turn,
our data suggest that alpha desynchronization over specic brain regions and at specic latencies may represent
a more sensitive measure of depression-related motivational decits than P3/LPP complex. is suggestion is
consistent with the notion that event-related oscillations not only reect stimulus-evoked oscillations similar to
the ERPs but also induced oscillations, which are not phase-locked to the stimulus event. It is therefore possible
that event-related oscillations may carry important information about emotional processing, which is not repre-
sented in the ERPs58. Further studies are needed to test dierences in emotional processing reected by ERP and
time-frequency analyses.
At the subjective level, self-report measures of valence and arousal did not dier between the group with
dysphoria and the control group, in line with previous studies in participants with subclinical depressive symp-
toms59,60 or in patients with clinically signicant depression61,62 (but see also Sloan et al.63). An explanation for
this null nding is that emotional experience was assessed according to a dimensional model of aective space
instead of a discrete emotion model, which may best capture depression-related dierences at the subjective level
(see Rottenberg et al.3). Otherwise, it can be suggested that decreased bilateral frontal and right-sided posterior
activation may precede alterations in subjective reports of emotional experience and therefore provide an early
measure of decits in the appetitive motivational system in individuals with dysphoria.
With respect to clinical implications, the current data show that individuals with dysphoria are character-
ized by under-engagement of appetitive rather than over-engagement of aversive motivational system7,10,64. In
line with this nding, there is recent evidence showing that depressed mood may improve through interven-
tions specically aimed at increasing appetitive motivation65. It can be also suggested that underactivation of the
approach-related motivational system in at-risk individuals (e.g., with dysphoria) may be involved as a risk factor
for the development of a full-blown depressive episode. Consistent with this suggestion, the clinical manifestation
and the course of depression have been reported to be worsened by underactivation of the appetitive motivational
system66. However, longitudinal studies are needed to test whether decreased approach-related motivational drive
may play a role in the transition from dysphoria to major depression.
e present study suers from some methodological shortcomings. First, the sample size included in this
study was relatively small and, second, it was composed almost exclusively by females. erefore, the current nd-
ings need to be replicated and extended to males in order to increase their generalizability. ird, whether partic-
ipants included in the study met the criteria for major depression, dysthymia or bipolar disorder in the past was
not investigated. Although having a history of major depression is unlikely to have aected the results obtained
in the group with dysphoria because the eect of current and past depression on alpha asymmetry is expected to
be the same, it might have partially confounded data obtained in healthy controls. It should be noted, however,
that 12-month period prevalence of depression range from 1% to 3% in pre-pubertal children and post-pubertal
adolescents67. According to this prevalence rate, and given that only university students were enrolled, the likeli-
hood of having a history of clinically signicant depression in participants assigned to healthy control group was
very low. erefore, the potential confounding eect of having a history of major depression was limited in the
present study. Lastly, the module A of the SCID-I interview was administered by only one trained psychologist,
which prevented us from evaluating the inter-rater reliability. Nonetheless, a high inter-rater reliability has been
previously reported for the majority of the disorders assessed by the SCID-I interview68.
To the best of our knowledge, this is the rst study investigating motivational decits in depression using a
time-frequency approach, according to the capability model of alpha asymmetries. e excellent temporal res-
olution of this approach gave us the opportunity to use discrete, short-lasting emotional stimuli needed to elicit
a strong activation of the approach- and withdrawal-related motivational systems, as proposed by the capability
model. In other words, the time-frequency approach allowed us to go beyond the measurement of a trait-like
decit in approach motivation, detailing how depressed mood aects transient motivational responses.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
9
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
In conclusion, the results obtained in the present study support the notion that individuals with dysphoria are
more likely to be under-engaged in processing approach- than avoidance-related motivationally stimuli rather
than the opposite pattern. Most importantly, these novel results add to the existing literature by suggesting that
transient reduction in alpha desynchronization involving bilateral frontal and right-lateralized parietal regions
may reect decits in the approach-related motivational system in depression.
Data availability
All data and MATLAB code will be made available upon request.
Received: 26 July 2019; Accepted: 4 November 2019;
Published: xx xx xxxx
References
1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 5th ed. (American Psychiatric Association,
Arlington, VA, 2013).
2. Clar, D. A. & Bec, A. T. Cognitive theory and therapy of anxiety and depression: Convergence with neurobiological ndings.
Trends Cogn. Sci. 14, 418–424, https://doi.org/10.1016/j.tics.2010.06.007 (2010).
3. ottenberg, J., Gross, J. J. & Gotlib, I. H. Emotion context insensitivity in major depressive disorder. J. Abnorm. Psychol. 114,
627–639, https://doi.org/10.1037/0021-843X.114.4.627 (2005).
4. Beeney, J. E., Levy, . N., Gatze-opp, L. M. & Hallquist, M. N. EEG asymmetry in borderline personality disorder and depression
following rejection. Personal. Disord. 5, 178–85, https://doi.org/10.1037/per0000032 (2014).
5. Golin, S., Hartman, S. A., latt, E. N., Munz, . & Wolfgang, G. L. Eects of self-esteem manipulation on arousal and reactions to
sad models in depressed and nondepressed college students. J. Abnorm. Psychol. 86, 435–439, https://doi.org/10.1037/0021-
843X.86.4.435 (1977).
6. Lewinsohn, P. M., L obitz, W. C. & Wilson, S. Sensitivity of depressed individuals to aversive stimuli. J. Abnorm. Psychol. 81, 259–263,
https://doi.org/10.1037/h0034529 (1973).
7. Messerotti Benvenuti, S., Mennella, ., Buodo, G. & Palomba, D. Dysphoria is associated with reduced cardiac vagal withdrawal
during the imagery of pleasant scripts: Evidence for the positive attenuation hypothesis. Biol. Psychol. 106, 28–38, https://doi.
org/10.1016/j.biopsycho.2014.11.017 (2015).
8. Messerotti Benvenuti, S., Mennella, ., Buodo, G. & Palomba, D. Frontal theta activity as an EEG correlate of mood-related
emotional processing in dysphoria. J. Psychopathol. Behav. Assess. 39, 241–252, https://doi.org/10.1007/s10862-016-9572-8 (2017).
9. Mennella, ., Messerotti Benvenuti, S., Buodo, G. & Palomba, D. Emotional modulation of alpha asymmetry in dysphoria: esults
from an emotional imagery tas. Int. J. Psychophysiol. 97, 113–119, https://doi.org/10.1016/j.ijpsycho.2015.05.013 (2015).
10. Messerotti Benvenuti, S., Buodo, G. & Palomba, D. Appetitive and aversive motivation in dysphoria: A time-domain and time-
frequency study of response inhibition. Biol. Psychol. 125, 12–27, https://doi.org/10.1016/j.biopsycho.2017.02.007 (2017).
11. Nussloc, ., Walden, . & Harmon-Jones, E. Asymmetrical frontal cortical activity associated with dierential ris for mood and
anxiety disorder symptoms: An DoC perspective. Int. J. Psychophysiol. 98, 249–261, https://doi.org/10.1016/j.ijpsycho.2015.06.004
(2015).
12. Admon, . & Pizzagalli, D. A. Dysfunctional reward processing in depression. Curr. Opin. Psychol. 4, 114–118, https://doi.
org/10.1016/j.copsyc.2014.12.011 (2015).
13. ottenberg, J. Mood and emotion in major depression. Curr. Dir. Psychol. Sci. 14, 167–170, https://doi.org/10.1111/j.0963-
7214.2005.00354.x (2005).
14. ottenberg, J. Major depressive disorder: Emerging evidence for emotion context insensitivity. In Emotion and psychopathology:
Bridging aective and clinical science (eds ottenberg, J. & Johnson, S. L.) 151–165 (American Psychological Society, Washington
DC, 2007).
15. Gotlib, I. H. Frontal EEG alpha asymmetry, depression, and cognitive functioning. Cogn. Emot. 12, 449–478, https://doi.
org/10.1080/026999398379673 (1998).
16. Schaer, C. E., Davidson, . J. & Saron, C. Frontal and parietal electroencephalogram asymmetry in depressed and nondepressed
subjects. Biol. Psychiatry 18, 753–762 (1983).
17. Allen, J. J. B., Urry, H. L., Hitt, S. . & Coan, J. A. e stability of resting frontal electroencephalographic asymmetry in depression.
Psychophysiology 41, 269–280, https://doi.org/10.1111/j.1469-8986.2003.00149.x (2004).
18. Henriques, J. B. & Davidson, . J. Left frontal hypoactivation in depression. J. Abnorm. Psychol. 100, 535–545, https://doi.
org/10.1037/0021-843X.100.4.535 (1991).
19. Henriques, J. B. & Davidson, . J. egional brain electrical asymmetries discriminate between previously depressed and healthy
control subjects. J. Abnorm. Psychol. 99, 22–31, https://doi.org/10.1037//0021-843X.99.1.22 (1990).
20. Stewart, J. L., Bismar, A. W., Towers, D. N., Coan, J. A. & Allen, J. J. B. esting frontal EEG asymmetry as an endophenotype for
depression ris: Sex-specic patterns of frontal brain asymmetry. J. Abnorm. Psychol. 119, 502–512, https://doi.org/10.1037/
a0019196 (2010).
21. Allen, J. J. B., eune, P. M., Schönenberg, M. & Nussloc, . Frontal EEG alpha asymmetry and emotion: From neural underpinnings
and methodological considerations to psychopathology and social cognition. Psychophysiology 55, 1–6, https://doi.org/10.1111/
psyp.13028 (2018).
22. Coan, J. A. & Allen, J. J. B. Frontal EEG asymmetry as a moderator and mediator of emotion. Biol. Psychol. 67, 7–49, https://doi.
org/10.1016/j.biopsycho.2004.03.002 (2004).
23. Davidson, . J. Anterior electrophysiological asymmetries, emotion, and depression: Conceptual and methodological conundrums.
Psychophysiology 35, 607–614, https://doi.org/10.1017/S0048577298000134 (1998).
24. Harmon-Jones, E. Clarifying the emotive functions of asymmetrical frontal cortical activity. Psychophysiology 40, 838–848, https://
doi.org/10.1111/1469-8986.00121 (2003).
25. ezni, S. J. & Allen, J. J. B. Frontal asymmetry as a mediator and moderator of emotion: An updated review. Psychophysiology 55,
e12965, https://doi.org/10.1111/psyp.12965 (2018).
26. Smith, E. E., Cavanagh, J. F. & Allen, J. J. B. Intracranial source activity (eLOETA) related to scalp-level asymmetry scores and
depression status. Psychophysiology 55, e13019, https://doi.org/10.1111/psyp.13019 (2018).
27. van der Vinne, N., Vollebregt, M. A., van Putten, M. J. A. M. & Arns, M. Frontal alpha asymmetry as a diagnostic marer in
depression: Fact or ction? A meta-analysis. Neuroimage Clin. 16, 79–87, https://doi.org/10.1016/j.nicl.2017.07.006 (2017).
28. Coan, J. A., Allen, J. J. B. & Mcnight, P. E. A capability model of individual dierences in frontal EEG asymmetry. Biol. Psychol. 72,
198–207, https://doi.org/10.1016/j.biopsycho.2005.10.003 (2006).
29. Stewart, J. L., Coan, J. A., Towers, D. N. & Allen, J. J. B. esting and tas-elicited prefrontal EEG alpha asymmetry in depression:
Support for the capability model. Psychophysiology 51, 446–455, https://doi.org/10.1111/psyp.12191 (2014).
30. Nelson, B. D., essel, E. M., lein, D. N. & Shanman, S. A. Depression symptom dimensions and asymmetrical frontal cortical
activity while anticipating reward. Psychophysiology 55, 1–14, https://doi.org/10.1111/psyp.12892 (2018).
Content courtesy of Springer Nature, terms of use apply. Rights reserved
10
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
31. Stewart, J. L., Coan, J. A., Towers, D. N. & Allen, J. J. B. Frontal EEG asymmetry during emotional challenge dierentiates individuals
with and without lifetime major depressive disorder. J. Aect. Disord. 129, 167–174, https://doi.org/10.1016/j.jad.2010.08.029
(2011).
32. Allen, J. J. B. & Cohen, M. X. Deconstructing the “resting” state: Exploring the temporal dynamics of frontal alpha asymmetry as an
endophenotype for depression. Front. Hum. Neurosci. 4, 232, https://doi.org/10.3389/fnhum.2010.00232 (2010).
33. Stewart, J. L., Towers, D. N., Coan, J. A. & Allen, J. J. B. e o-neglected role of parietal EEG asymmetry and ris for major
depressive disorder. Psychophysiology 48, 82–95, https://doi.org/10.1111/j.1469-8986.2010.01035.x (2011).
34. Bruder, G. E., Tene, C. E., Warner, V. & Nomura, Y. Electroencephalographic measures of regional hemispheric activity in ospring
at ris for depressive disorders. Biol. Psychiatry 57, 328–335, https://doi.org/10.1016/j.biopsych.2004.11.015 (2005).
35. Bruder, G. E. Frontal and parietotemporal asymmetries in depressive disorders: Behavioral, electrophysiologic and neuroimaging
ndings. In e asymmetrical brain (eds Hugdahl, . & Davidson, . J.) 719–742 (MIT Press, Cambridge, MA, 2003).
36. Heller, W. Neuropsychological mechanisms of individual dierences in emotion, personality, and arousal. Neuropsychology 7,
476–489, https://doi.org/10.1037/0894-4105.7.4.476 (1993).
37. Heller, W. & Nitsce, J. B. egional brain activity in emotion: A framewor for understanding cognition in depresion. Cogn. Emot.
11, 637–661, https://doi.org/10.1080/026999397379845a (1997).
38. Mennella, . et al. The two faces of avoidance: Time-frequency correlates of motivational disposition in blood phobia.
Psychophysiology 54, 1606–1620, https://doi.org/10.1111/psyp.12904 (2017).
39. Lang, P. J., Bradley, M. M. & Cuthbert, B. N. International affective picture system (IAPS): Affective ratings of pictures and
instruction manual. Technical report A-8. (University of Florida, Gainesville, FL, 2008).
40. Lang, P. J. & Bradley, M. M. Emotion and the motivational brain. Biol. Psychol. 84, 437–450, https://doi.org/10.1016/j.
biopsycho.2009.10.007 (2010).
41. Schupp, H. T., Flaisch, T., Stocburger, J. & Junghöfer, M. Emotion and attention: Eventrelated brain potential studies. Prog. Brain
Res. 156, 31–51, https://doi.org/10.1016/S0079-6123(06)56002-9 (2006).
42. Messerotti Benvenuti, S., Bianchin, M. & Angrilli, A. Posture aects emotional responses: A Head Down Bed est and EP study.
Brain Cogn. 82, 313–318, https://doi.org/10.1016/j.bandc.2013.05.006 (2013).
43. Bec, A. T., Steer, . A. & Brown, G. . (1996). Beck depression inventory. Second edition manual. (Psychological Corporation, San
Antonio, TX, 1996).
44. Ghisi, M., Flebus, G. B., Montano, A., Sanavio, E. & Sica, C. Beck depression inventory-II BDI-II. Manuale. (O.S. Organizzazioni
Speciali, Firenze, 2006).
45. First, M. B., Spitzer, . L., Gibbon, M. & Williams, J. B. W. Structured clinical interview for DSM-IV Axis I Disorders (SCID I). Clinical
version. (American Psychiatric Press, Washington, DC, 1997).
46. Mazzi, F., Morosini, P., De Girolamo, G., Lussetti, M. & Guaraldi, G. P. SCID-I Structured Clinical Interview for DSM-IV Axis I
Disorders (Italian version). (O.S. Organizzazioni Speciali, Firenze, 2000).
47. Bradley, M. M. & Lang, P. J. Measuring emotion: e self-assessment maniin and the semantic dierential. J. Behav. er. Exp.
Psychiatry 25, 49–59, https://doi.org/10.1016/0005-7916(94)90063-9 (1994).
48. Delorme, A. & Maeig, S. EEGLAB: An open source toolbox for analysis of single-trial EEG dynamics including independent
component analysis. J. Neurosci. Methods 134, 9–21, https://doi.org/10.1016/j.jneumeth.2003.10.009 (2004).
49. Tadel, F., Baillet, S., Mosher, J. C., Pantazis, D. & Leahy, . M. Brainstorm: A user-friendly application for MEG/EEG. analysis.
Comput. Intell. Neurosci. 2011, 879716, https://doi.org/10.1155/2011/879716 (2011).
50. Hedges, L. V. & Olin, I. Statistical methods for meta-analysis. (Academic Press, Orlando, 1985).
51. Maris, E. & Oostenveld, . Nonparametric statistical testing of EEG and MEGdata. J. Neurosci. Methods 164, 177–190, https://doi.
org/10.1016/j.jneumeth.2007.03.024 (2007).
52. Insel, T. et al. esearch Domain Criteria (DoC): Toward a new classication framewor for research on mental disorders. Am. J.
Psychiatry 167, 748–751, https://doi.org/10.1176/appi.ajp.2010.09091379 (2010).
53. Schubring, D. & Schupp, H. T. Aective picture processing: Alpha and lower betaband desynchronization reects emotional
arousal. Psychophysiology e13386, https://doi.org/10.1111/psyp.13386 (2019).
54. de Cesarei, A. & Codispoti, M. Aective modulation of the LPP and αED during picture viewing. Psychophysiology 48, 1397–1404,
https://doi.org/10.1111/j.1469-8986.2011.01204.x (2011).
55. Baumgartner, T., Esslen, M. & Jänce, L. From emotion perception to emotion experience: Emotions evoed by pictures and classical
music. Int. J. Psychophysiol. 60, 34–43, https://doi.org/10.1016/j.ijpsycho.2005.04.007(2006).
56. Aftanas, L. I., eva, N. V., Varlamov, A. A., Pavlov, S. V. & Mahnev, V. P. Analysis of evoed EEG synchronization and
desynchronization in conditions of emotional activation in humans: Temporal and topographic characteristics. Neurosci. Behav.
Physiol. 34, 859–867, https://doi.org/10.1023/B:NEAB.0000038139.39812.eb (2004).
57. Aanas, L. I., Varlamov, A. A., Pavlov, S. V., Mahnev, V. P. & eva, N. V. Time-dependent cortical asymmetries induced by
emotional arousal: EEG analysis of event-related synchronization and desynchronization in individually dened frequency bands.
Int. J. Psychophysiol. 44, 67–82, https://doi.org/10.1016/S0167-8760(01)00194-5 (2002).
58. Herrmann, C. S., ach, S., Vossuhl, J. & Strüber, D. Time–frequency analysis of event-related potentials: A brief tutorial. Brain
Top o g r. 27, 438–450, https://doi.org/10.1007/s10548-013-0327-5 (2014).
59. Mneimne, M., McDermut, W. & Powers, A. S. Aective ratings and startle modulation in people with nonclinical depression.
Emotion 8, 552–559, https://doi.org/10.1037/a0012827 (2008).
60. Sloan, D. M. & Sandt, A. . Depressed mood and emotional responding. Biol. Psychol. 84, 368–374, https://doi.org/10.1016/j.
biopsycho.2010.04.004 (2010).
61. Allen, N. B., Trinder, J. & Brennan, C. Aective startle modulation in clinical depression: Preliminary ndings. Biol. Psychiatry 46,
542–550, https://doi.org/10.1016/S0006-3223(99)00025-6 (1999).
62. Dichter, G., Tomaren, A., Shelton, . & Sutton, S. Early- and late-onset startle modulation in unipolar depression. Psychophysiology
41, 433–440, https://doi.org/10.1111/j.1469-8986.00162.x (2004).
63. Sloan, D. M., Strauss, M. E., Quir, S. W. & Sajatovic, M. Subjective and expressive emotional responses in depression. J. Aect.
Disord. 46, 135–141, https://doi.org/10.1016/S0165-0327(97)00097-9 (1997).
64. Buodo, G., Mento, G., Sarlo, M. & Palomba, D. Neural correlates of attention to emotional facial expressions in dysphoria. Cogn.
Emot. 29, 604–620, https://doi.org/10.1080/02699931.2014.926862 (2015).
65. Strauman, T. J. et al. Microinterventions targeting regulatory focus and regulatory t selectively reduce dysphoric and anxious
mood. Behav. Res. er. 72, 18–29, https://doi.org/10.1016/j.brat.2015.06.003 (2015).
66. asch, . L., ottenberg, J., Arnow, B. A. & Gotlib, I. H. Behavioral activation and inhibition systems and the severity and course of
depression. J. Abnorm. Psychol. 111, 589–597, https://doi.org/10.1037//0021-843X.111.4.589 (2002).
67. Angold, A., & Costello, E. J. e epidemiology of depression in children and adolescents. In e depressed child and adolescent (ed.
Goodyer, I. M.) 143–178 (Cambridge University Press, New Yor, 2001).
68. Sre, I., Onstad, S., Torgersen, S. & ringlen, E. High interrater reliability for the structured clinical interview for DSM-III- Axis I
(SCID-I). Acta Psychiatr. Scand. 84, 167–173, https://doi.org/10.1111/j.1600-0447.1991.tb03123.x (1991).
Content courtesy of Springer Nature, terms of use apply. Rights reserved
11
SCIENTIFIC REPORTS | (2019) 9:17129 | https://doi.org/10.1038/s41598-019-53639-8
www.nature.com/scientificreports
www.nature.com/scientificreports/
Acknowledgements
e study was supported by a grant from MIUR (Dipartimenti di Eccellenza DM 11/05/2017 n. 262) to the
Department of General Psychology, University of Padua.
Author contributions
S.M.B., G.B. and D.P. conceived and designed the study; S.M.B., G.B., R.M. and E.D.B. conducted the study; R.M.
contributed to methodological and analytic tools; S.M.B., R.M. and E.D.B. analyzed the data; S.M.B., G.B. and
R.M. wrote the paper, and all authors reviewed the manuscript.
Competing interests
e authors declare no competing interests.
Additional information
Correspondence and requests for materials should be addressed to S.M.B.
Reprints and permissions information is available at www.nature.com/reprints.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and
institutional aliations.
Open Access This article is licensed under a Creative Commons Attribution 4.0 International
License, which permits use, sharing, adaptation, distribution and reproduction in any medium or
format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Cre-
ative Commons license, and indicate if changes were made. e images or other third party material in this
article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the
material. If material is not included in the article’s Creative Commons license and your intended use is not per-
mitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the
copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
© e Author(s) 2019
Content courtesy of Springer Nature, terms of use apply. Rights reserved
1.
2.
3.
4.
5.
6.
Terms and Conditions
Springer Nature journal content, brought to you courtesy of Springer Nature Customer Service Center GmbH (“Springer Nature”).
Springer Nature supports a reasonable amount of sharing of research papers by authors, subscribers and authorised users (“Users”), for small-
scale personal, non-commercial use provided that all copyright, trade and service marks and other proprietary notices are maintained. By
accessing, sharing, receiving or otherwise using the Springer Nature journal content you agree to these terms of use (“Terms”). For these
purposes, Springer Nature considers academic use (by researchers and students) to be non-commercial.
These Terms are supplementary and will apply in addition to any applicable website terms and conditions, a relevant site licence or a personal
subscription. These Terms will prevail over any conflict or ambiguity with regards to the relevant terms, a site licence or a personal subscription
(to the extent of the conflict or ambiguity only). For Creative Commons-licensed articles, the terms of the Creative Commons license used will
apply.
We collect and use personal data to provide access to the Springer Nature journal content. We may also use these personal data internally within
ResearchGate and Springer Nature and as agreed share it, in an anonymised way, for purposes of tracking, analysis and reporting. We will not
otherwise disclose your personal data outside the ResearchGate or the Springer Nature group of companies unless we have your permission as
detailed in the Privacy Policy.
While Users may use the Springer Nature journal content for small scale, personal non-commercial use, it is important to note that Users may
not:
use such content for the purpose of providing other users with access on a regular or large scale basis or as a means to circumvent access
control;
use such content where to do so would be considered a criminal or statutory offence in any jurisdiction, or gives rise to civil liability, or is
otherwise unlawful;
falsely or misleadingly imply or suggest endorsement, approval , sponsorship, or association unless explicitly agreed to by Springer Nature in
writing;
use bots or other automated methods to access the content or redirect messages
override any security feature or exclusionary protocol; or
share the content in order to create substitute for Springer Nature products or services or a systematic database of Springer Nature journal
content.
In line with the restriction against commercial use, Springer Nature does not permit the creation of a product or service that creates revenue,
royalties, rent or income from our content or its inclusion as part of a paid for service or for other commercial gain. Springer Nature journal
content cannot be used for inter-library loans and librarians may not upload Springer Nature journal content on a large scale into their, or any
other, institutional repository.
These terms of use are reviewed regularly and may be amended at any time. Springer Nature is not obligated to publish any information or
content on this website and may remove it or features or functionality at our sole discretion, at any time with or without notice. Springer Nature
may revoke this licence to you at any time and remove access to any copies of the Springer Nature journal content which have been saved.
To the fullest extent permitted by law, Springer Nature makes no warranties, representations or guarantees to Users, either express or implied
with respect to the Springer nature journal content and all parties disclaim and waive any implied warranties or warranties imposed by law,
including merchantability or fitness for any particular purpose.
Please note that these rights do not automatically extend to content, data or other material published by Springer Nature that may be licensed
from third parties.
If you would like to use or distribute our Springer Nature journal content to a wider audience or on a regular basis or in any other manner not
expressly permitted by these Terms, please contact Springer Nature at
onlineservice@springernature.com
... Although this model is coherent with depression's feature of sustained negative affect, it is not fully supported by recent empirical evidence suggesting, instead, that depressed mood is mostly linked to a reduced emotional responding to positively valenced or rewarding stimuli (e.g. 10,[13][14][15][16][17][18][19] ). This second view, known as the positive attenuation hypothesis, holds that depressive symptoms are mostly linked to reduced emotional responsiveness to pleasant content, indicating a hypoactivation of the approach-related motivational system in the brain 14,15,[17][18][19][20] . ...
... 10,[13][14][15][16][17][18][19] ). This second view, known as the positive attenuation hypothesis, holds that depressive symptoms are mostly linked to reduced emotional responsiveness to pleasant content, indicating a hypoactivation of the approach-related motivational system in the brain 14,15,[17][18][19][20] . Notably, the hypoactivation of approach-related motivation represents an important risk factor for the development of depression 8,21 . ...
... An asymmetric pattern of alpha activity, with increased alpha in the left frontal lobe compared to the right, reflects a hypoactivation of the approach-related motivation system and has long been considered to represent a potential biomarker for depression in resting-state conditions ( 52,53 , for a review see 54 ) and even more in emotional contexts 55 . However, to date, only a few studies have examined alpha asymmetry during emotional processing in dysphoria or depression 15,18,56,57 . Also, most studies have analyzed alpha activity only at anterior scalp sites, even if asymmetry in the alpha in depression has also been reported at posterior scalp sites. ...
Article
Full-text available
To date, affective and cognitive processing of emotional information in individuals with depressive symptoms have been examined through peripheral psychophysiological measures, event-related potentials, and time–frequency analysis of oscillatory activity. However, electrocortical correlates of emotional and cognitive processing of affective content in depression have not been fully understood. Time–frequency analysis of electroencephalographic activity allows disentangling the brain's parallel processing of information. The present study employed a time–frequency approach to simultaneously examine affective disposition and cognitive processing during the viewing of emotional stimuli in dysphoria. Time–frequency event-related changes were examined during the viewing of pleasant, neutral and unpleasant pictures in 24 individuals with dysphoria and 24 controls. Affective disposition was indexed by delta and alpha power, while theta power was employed as a correlate of cognitive elaboration of the stimuli. Cluster-based statistics revealed a centro-parietal reduction in delta power for pleasant stimuli in individuals with dysphoria relative to controls. Also, dysphoria was characterized by an early fronto-central increase in theta power for unpleasant stimuli relative to neutral and pleasant ones. Comparatively, controls were characterized by a late fronto-central and occipital reduction in theta power for unpleasant stimuli relative to neutral and pleasant. The present study granted novel insights on the interrelated facets of affective elaboration in dysphoria, mainly characterized by a hypoactivation of the approach-related motivational system and a sustained facilitated cognitive processing of unpleasant stimuli.
... Given these premises, identifying factors and mechanisms that elevate the risk for depression, especially in young adults, is of fundamental importance for effectively preventing and early identifying depression. Several features characterizing the risk of developing major depressive disorder (MDD) have been recognized, such as some personality traits (Malinowski et al., 2017;Sedlinská et al., 2021;Takahashi et al., 2021), blunted neural response to rewards (Messerotti Benvenuti et al., 2019;Moretta et al., 2021;Weinberg et al., 2015), and dysfunctional cognitive biases (Keller et al., 2019;Murrough et al., 2011;Nieto et al., 2020;Platt et al., 2017). When studying vulnerability factors for depression as possible targets for early identification and prevention programs, an important question is whether these factors can help answer why depression is heritable. ...
Article
Background Despite the evidence of increased levels of rumination and reduced heart rate variability (HRV) in depression, whether these measures can be considered early indicators of vulnerability to depression has yet to be investigated. Therefore, the present study aimed to investigate both levels of rumination and resting HRV in individuals with familial risk for depression that is the most reliable risk factor for the disorder. Methods Rumination and vagally-mediated HRV were assessed using the Ruminative Response Scale and a smartphone-based photoelectric volumetric pulse wave assay, respectively, in 25 individuals who had family history of depression (but did not report current depressive symptoms), 15 individuals who reported depressive symptoms (but had no family history of depression), and 25 controls (without depressive symptoms and family history of depression). Results: Individuals with depressive symptoms and those with a family history of depression were characterized by higher levels of rumination and lower cardiac vagal control than controls. Limitations Given the small sample size, this study should be used to design larger confirmatory studies; the cross-sectional nature of the study does not allow discussing the results in terms of cause-effect relationships. Conclusions Our findings suggested that individuals at risk of developing depression, also in absence of depressive symptoms, are defined by defective self-regulation capacity that may lead to future depression episodes. Increased ruminative thoughts and reduced HRV may represent early indicators of vulnerability to depression. Effective prevention programs designed to reduce rumination and/or increase HRV may reduce the risk of developing a full-blown depressive episode.
... Moreover, we expected that stress-related humor would be more effective than stress-unrelated humor, as it facilitates confrontation with the stressor and shifts its threatening meaning through the powerful mechanism of humorous reappraisal. Stress-related humor could be particularly adaptive for individuals prone to depression in view the detrimental impact of their well-documented deficits in approach-related motivation 41 . ...
Article
Full-text available
Enhancing emotion regulation among previously depressed people is crucial for improving their resilience and reducing relapse. Therefore, emphasis is placed on determining effective regulation strategies, particularly those that, besides down-regulating negative emotions, also up-regulate positive emotions. One promising strategy, with great potential in both these respects, is humor. It is unclear, however, what type of humor is most adaptive in remitted depression. This study compared two distinct humor-based strategies: stress-related humor and stress-unrelated humor. Outpatients with remitted depression (N = 94) participated in a randomized experiment evoking personal stress and the subsequent application of stress-related humor, stress-unrelated humor, or a non-humorous regulation. They repeatedly reported positive and negative emotions (at four time points) and experienced distress (at three time points). There were also assessments of selective attention, subsequent performance, effort, and intrusive thoughts. Unlike non-humorous regulation, humor-based strategies had adaptive consequences, both immediately and after a delay; however, stress-unrelated humor was most beneficial and was the only effective strategy when attention deficits were present. Humor, especially if unrelated to stressors, might broaden the repertoire of powerful emotion regulation strategies in remitted depression. Humorous focusing on distress can be detrimental for patients with attention impairment. Clinical trial registration: The study was registered under the number ISRCTN86314628 (20/09/2021).
... More importantly, a connectivity-based EEG analysis suggests an increase in alpha-band connectivity between the anterior cingulate cortex and both the prefrontal cortex 80 . It has also been proposed that reduced alpha desynchronization in a network involving bilateral frontal and right-lateralized parietal regions may provide a specific measure of deficits in approach-related motivation in depression 81 . Using graph theoretical methods, another study shows that disrupted global and local network indices in MDD patients were revealed in alpha band 11 . ...
Article
Full-text available
Emerging evidence showed that major depressive disorder (MDD) is associated with disruptions of brain structural and functional networks, rather than impairment of isolated brain region. Thus, connectome-based models capable of predicting the depression severity at the individual level can be clinically useful. Here, we applied a machine-learning approach to predict the severity of depression using resting-state networks derived from source-reconstructed Electroencephalography (EEG) signals. Using regression models and three independent EEG datasets (N = 328), we tested whether resting state functional connectivity could predict individual depression score. On the first dataset, results showed that individuals scores could be reasonably predicted (r = 0.6, p = 4 × 10–18) using intrinsic functional connectivity in the EEG alpha band (8–13 Hz). In particular, the brain regions which contributed the most to the predictive network belong to the default mode network. We further tested the predictive potential of the established model by conducting two external validations on (N1 = 53, N2 = 154). Results showed statistically significant correlations between the predicted and the measured depression scale scores (r1 = 0.52, r2 = 0.44, p < 0.001). These findings lay the foundation for developing a generalizable and scientifically interpretable EEG network-based markers that can ultimately support clinicians in a biologically-based characterization of MDD.
... Indeed, previous studies reported that individuals with depressive symptoms were more reactive to laboratory stressors, as indicated by elevated heart rate, blood pressure responses, and higher cortisol levels during the post-stress recovery period (Betensky and Contrada, 2010;Burke et al., 2005;Kibler and Ma, 2004). However, while these findings suggest a heightened physiological reactivity to negative stressors in depression (Edmondson et al., 2014), numerous recent studies corroborate with the view that depression is predominantly associated with a blunted reactivity towards positively-valenced content (e.g., Sloan et al., 2001;Messerotti Benvenuti et al., 2015;Messerotti Benvenuti, Mennella, et al., 2017, Messerotti Benvenuti et al., 2019Nelson et al., 2016;Winer and Salem, 2016). In the same line, the heightened processing of unpleasant stimuli in individuals with pre-trauma anxiety was suggested to intensify the negative features of traumatic events (e.g., Bar-Haim et al., 2007;Dillon et al., 2014;Kujawa et al., 2015;White et al., 2010), resulting in its maladaptive processing and altered stress response (Kok et al., 2016;Weems et al., 2007;Schweizer et al., 2017). ...
Article
Background Considering that the elevated distress caused by the COVID-19 pandemic, in some cases, led to post-traumatic stress symptoms (PTSS), it has been proposed as a specific traumatic event. The present longitudinal study investigated pre-pandemic motivated attention to emotional stimuli, as indexed by Late Positive Potential (LPP) amplitude, in relation with the potential differential role of anxiety and depressive symptoms in predicting PTSS severity related to the COVID-19 pandemic. Methods A total of 79 university students initially completed self-report measures of Depress. Anxiety along with a passive viewing task of emotional (pleasant, unpleasant) and neutral pictures while an electroencephalogram was recorded. In December 2020, 57 participants completed a questionnaire assessing PTSS. Results Significant interactions between anxiety and LPP emerged in predicting pandemic-related PTSS, where greater anxiety symptoms predicted PTSS only in individuals with greater LPP to unpleasant or with reduced LPP to pleasant stimuli. Limitations The prevalence of the female sex, the relatively young age of the participants, as well as the fact that they were all enrolled in a University course might not allow the generalization of the findings. Conclusions Taken together, the present longitudinal study provided novel evidence on EEG predictors of pandemic-related PTSS that might be useful for the prevention and treatment of PTSS. Indeed, assessing anxiety symptoms and pre-trauma LPP to emotional stimuli might be a useful target for identifying individuals that are more vulnerable to the development of PTSS during times of crisis.
... 28,29 ). Low PA, in particular the diminished ability to experience pleasure and joy (anhedonia), is considered a risk marker for depressive disorders 28,30 and is a cardinal symptom of depression 29,31 , known to be associated with significant and pervasive impairments in social functioning (see reviews 32,33 ). ...
Article
Full-text available
Study Objectives Total sleep deprivation is known to have significant detrimental effects on cognitive and socio-emotional functioning. Nonetheless, the mechanisms by which total sleep loss disturbs decision-making in social contexts are poorly understood. Here, we investigated the impact of total sleep deprivation on approach/avoidance decisions when faced with threatening individuals, as well as the potential moderating role of sleep-related mood changes. Methods Participants (n = 34) made spontaneous approach/avoidance decisions in the presence of task-irrelevant angry or fearful individuals, while rested or totally sleep deprived (27 hours of continuous wakefulness). Sleep-related changes in mood and sustained attention were assessed using the Positive and Negative Affective Scale and the psychomotor vigilance task, respectively. Results Rested participants avoided both fearful and angry individuals, with stronger avoidance for angry individuals, in line with previous results. On the contrary, totally sleep deprived participants favored neither approach nor avoidance of fearful individuals, while they still comparably avoided angry individuals. Drift-diffusion models showed that this effect was accounted for by the fact that total sleep deprivation reduced value-based evidence accumulation toward avoidance during decision making. Finally, the reduction of positive mood after total sleep deprivation positively correlated with the reduction of fearful display avoidance. Importantly, this correlation was not mediated by a sleep-related reduction in sustained attention. Conclusions All together, these findings support the underestimated role of positive mood-state alterations caused by total sleep loss on approach/avoidance decisions when facing ambiguous socio-emotional displays, such as fear.
Article
Full-text available
Processing of negative affective pictures typically leads to desynchronization of alpha-to-beta frequencies (ERD) and synchronization of gamma frequencies (ERS). Given that in predictive coding higher frequencies have been associated with prediction errors, while lower frequencies have been linked to expectations, we tested the hypothesis that alpha-to-beta ERD and gamma ERS induced by aversive pictures are associated with expectations and prediction errors, respectively. We recorded EEG while volunteers were involved in a probabilistically cued affective picture task using three different negative valences to produce expectations and prediction errors. Our data show that alpha-to-beta band activity after stimulus presentation was related to the expected valence of the stimulus as predicted by a cue. The absolute mismatch of the expected and actual valence, which denotes an absolute prediction error was related to increases in alpha, beta and gamma band activity. This demonstrates that top-down predictions and bottom-up prediction errors are represented in typical spectral patterns associated with affective picture processing. This study provides direct experimental evidence that negative affective picture processing can be described by neuronal predictive coding computations.
Article
Full-text available
Approach and avoidance tendencies play an important role in everyday food choices when choosing between high-caloric, rather unhealthy, and low-caloric, rather healthy options. On a neuronal level, approach and avoidance motivation have been associated with asymmetrical activity of the frontal cortex, often quantified by alpha power averaged over several seconds of resting electroencephalogram (EEG). Going beyond the analysis of resting EEG, the present study aimed to investigate asymmetrical frontal activity in direct response to food stimuli in an event-related design and in combination with event-related potentials (ERPs). Therefore, a sample of 56 young and healthy participants completed a food choice task. They were asked to choose from a selection of high-caloric and low-caloric foods which they would want to eat on a normal day (baseline), when being on a diet, and in a reward situation. On the behavioural level, there was a clear preference for low-caloric foods. Well in line with that, time-frequency analyses of alpha asymmetry revealed relatively stronger temporary (950-1175 ms) left-hemispheric frontal activity, that is, a stronger approach tendency, in response to low-caloric as compared to high-caloric foods. Furthermore, larger P300 for low-caloric foods indicated an increased task relevance of low-caloric foods in the baseline and the reward situation. In contrast, the late positive potential (LPP), an index of subjective value, was larger for high- as compared to low-caloric foods, reflecting the intrinsic rewarding properties of high-caloric foods. ERPs, but not frontal alpha asymmetry, were influenced by the situational context.
Article
The present study aimed to investigate emotional processing in dysphoria. To this end, the amplitude of the Late Positive Potential (LPP) and cardiac deceleration were assessed during the passive viewing of affective (pleasant, neutral, and unpleasant) pictures in 26 individuals with dysphoria and in 25 non-depressed controls. The group with dysphoria revealed a smaller LPP amplitude than the group without dysphoria in response to pleasant and neutral, but not unpleasant, stimuli at centro-parieto-occipital sites. Interestingly, whereas both groups showed cardiac deceleration when viewing pleasant compared to neutral pictures (3–6 s time window), only individuals with dysphoria showed a prolonged cardiac deceleration in response to unpleasant stimuli as compared with neutral ones. This study suggests that dysphoria is characterized by reduced motivated attentional allocation to positive information and by sustained intake of unpleasant information. Overall, the present findings provide novel insights into the characterization of valence-specific attentional processes in dysphoria as potential vulnerability factors for clinically significant depression.
Chapter
Several neurological and psychiatric disorders including, but not limited to, neurological injury, depression, epilepsy, or schizophrenia have been associated with autonomic dysfunctions. However, only a few studies have quantitatively assessed the link between psychiatric, neurological, and cardiac disorders.
Article
Full-text available
Frontal EEG alpha asymmetry provides a promising index of depression risk, yet very little is known about the neural sources of alpha asymmetry. To identify these sources, this study examined alpha asymmetry using a distributed inverse solution: exact low resolution brain electromagnetic tomography (eLORETA). Findings implicated a generator in lateral midfrontal regions that contributed to both surface asymmetry and depression risk. Participants with any lifetime history of depressive episodes were characterized by less left than right activity in the precentral gyrus and midfrontal gyrus. Anhedonia accounted for a significant portion of the relationship between alpha asymmetry and lifetime major depressive disorder. Results are suggestive of convergence between motivational and capability models of asymmetry and replicate results from experimental studies in a large resting-state data set. The capability model of frontal alpha asymmetry is contextualized in terms of motor preparedness following emotional mobilization.
Article
Full-text available
Background Frontal alpha asymmetry (FAA) has frequently been reported as potential discriminator between depressed and healthy individuals, although contradicting results have been published. The aim of the current study was to provide an up to date meta-analysis on the diagnostic value of FAA in major depressive disorder (MDD) and to further investigate discrepancies in a large cross-sectional dataset. Methods SCOPUS database was searched through February 2017. Studies were included if the article reported on both MDD and controls, provided an FAA measure involving EEG electrodes F3/F4, and provided data regarding potential covariates. Hedges' d was calculated from FAA means and standard deviations (SDs). Potential covariates, such as age and gender, were explored. Post hoc analysis was performed to elucidate interindividual differences that could explain interstudy discrepancies. Results 16 studies were included (MDD: n = 1883, controls: n = 2161). After resolving significant heterogeneity by excluding studies, a non-significant Grand Mean effect size (ES) was obtained (d = − 0.007;CI = [− 0.090]–[0.075]). Crosssectional analyses showed a significant three-way interaction for Gender × Age × Depression severity in the depressed group, which was prospectively replicated in an independent sample. Conclusions The main result was a non-significant, negligible ES, demonstrating limited diagnostic value of FAA in MDD. The high degree of heterogeneity across studies indicates covariate influence, as was confirmed by crosssectional analyses, suggesting future studies should address this Gender × Age × Depression severity interaction. Upcoming studies should focus more on prognostic and research domain usages of FAA rather than a pure diagnostic tool.
Article
Full-text available
Several studies have examined the neural correlates of mood-related emotional processing in depression, showing a greater reduction of activity in the rostral anterior cingulate cortex (rACC) in response to pleasant relative to unpleasant stimuli in depressed individuals, and the opposite pattern in healthy controls. The present study aimed at examining whether frontal theta activity—an electrophysiological measure of rACC activity—could be a reliable EEG correlate of mood-related emotional processing in individuals with dysphoria. To this end, the EEG was recorded in 27 individuals with dysphoria and 29 individuals without dysphoria during an emotional imagery task, including pleasant, neutral and unpleasant scripts. Self-reported valence, arousal and vividness, and changes in frontal theta activity were measured during the task. Frontal theta activity was more reduced from baseline to the imagery of pleasant relative to unpleasant scripts in the group with dysphoria, whereas the opposite pattern of reduction was noted in the group without dysphoria. In addition, more severe depressive symptoms were correlated with greater reduction in frontal theta activity in response to pleasant, but not neutral and unpleasant, scripts. No differences between groups in subjective ratings were noted. Consistent with the key role of rACC activity in depression-related emotional dysregulation, these findings suggest that frontal theta activity may be an EEG correlate of mood-related emotional processing in dysphoria. The current study also suggests that dysphoria is more likely to be associated with abnormal processing of pleasant rather than unpleasant stimuli.
Article
EEG power analysis is firmly established in the cognitive domain. This contrasts with emotional stimulus processing, which thus far has yielded a complex and ambiguous pattern of findings. To further advance understanding, the present study examined emotional stimulus processing in the context of task variations and baseline activity, which included several manipulation checks as well as internal replication of findings across conditions. Participants (N = 16) viewed erotic and romantic pictures, differing in stimulus arousal. Pictures were presented briefly (120 ms), and intertrial interval was systematically varied (~1 vs. ~8 s). In one condition, participants passively viewed the pictures, in the other, they performed an active picture categorization task. The processing of erotic compared to romantic images was associated with a decrease in power in the alpha and lower beta band in posterior and anterior sensor clusters between 600–1,000 ms poststimulus. The finding was robust and confirmed across conditions, different quantifications, and independent from baseline activity. Furthermore, key findings regarding explicit task effects as well as ERPs sensitive to emotional arousal were replicated. Results are discussed with respect to the hypothesis that alpha‐ and lower beta‐band activity may reflect cortical activation associated with emotional stimulus significance.
Article
For over 35 years, research has examined frontal alpha EEG asymmetry, discussed in terms of relative left frontal activity (rLFA) in the present review, as a concurrent and prospective marker of affective processing and psychopathology. Because rLFA may index (a) neural correlates of frontal asymmetry, or (b) psychological constructs to which frontal asymmetry relates, rLFA can advance our understanding of both neural and psychological models of emotion and psychopathology. In order to improve such understanding, the specific role of rLFA in extending or challenging existing theory must be clear to researchers and readers alike. In particular, in 2004, Coan and Allen argued that examination of rLFA as a mediator or moderator may improve our theoretical understanding of rLFA. Despite being a commonly cited paper in the field, most rLFA research today still fails to acknowledge the statistical role of rLFA in the research. The aim of the present paper is to (a) convince the reader of the importance of distinguishing rLFA as a predictor, outcome, mediator, or moderator in order to conduct theory-driven research, and (b) highlight some of the major advances in rLFA literature since the review by Coan and Allen (2004) in the framework of mediators and moderators. We selected a broad range of search terms to capture relevant rLFA research and included only those studies utilizing established methods for rLFA measurement.
Article
Contrary to other phobias, individuals with blood phobia do not show a clear-cut withdrawal disposition from the feared stimulus. The study of response inhibition provides insights into reduced action disposition in blood phobia. Twenty individuals with and 20 without blood phobia completed an emotional go/no-go task including phobia-related pictures, as well as phobia-unrelated unpleasant, neutral, and pleasant stimuli. Behavioral results did not indicate a phobia-specific reduced action disposition in the phobic group. Time-frequency decomposition of event-related EEG data showed a reduction of right prefrontal activity, as indexed by an increase in alpha power (200 ms), for no-go mutilation trials in the phobic group but not in controls. Moreover, theta power (300 ms) increased specifically for phobia-related pictures in individuals with, but not without, blood phobia, irrespective of go or no-go trial types. Passive avoidance of phobia-related stimuli subtended by the increased alpha in the right prefrontal cortex, associated with increased emotional salience indexed by theta synchronization, represents a possible neurophysiological correlate of the conflicting motivational response in blood phobia. Through the novel use of time-frequency decomposition in an emotional go/no-go task, the present study contributed to clarifying the neurophysiological correlates of the overlapping motivational tendencies in blood phobia.
Article
Unipolar depression has been characterized as involving diminished approach motivation and reward sensitivity. A psychophysiological indicator of approach motivation involves an asymmetry in frontal EEG activity, such that greater left relative to right frontal cortical activity indicates increased approach motivation. Consistent with the perspective of reduced approach motivation tendencies, depression has been associated with decreased relative left frontal cortical activity. To date, supporting research has primarily relied on categorical diagnoses or composite symptom counts. However, given the heterogeneity in depression, it is unclear what specific symptom dimensions relate to decreased relative left frontal cortical activity. The present study examined the association between multiple depression symptom dimensions and asymmetrical frontal cortical activity while anticipating reward in separate undergraduate (n = 75) and clinical samples (current major depressive disorder [n = 68] and never depressed controls [n = 67]). All participants completed the Inventory of Depression and Anxiety Symptoms, a self-report measure of factor-analytically derived symptom dimensions. Frontal cortical activity was assessed during a computerized slot machine task while participants anticipated potential monetary reward or no incentive. In undergraduates with low depression symptoms and never depressed controls, reward trials relative to no-incentive trials elicited greater relative left frontal cortical activity. Furthermore, in both samples across all participants, increased dysphoria and lassitude symptoms were associated with decreased relative left frontal cortical activity while anticipating reward. The present study suggests that depression symptoms consistent with motivational disengagement are associated with decreased relative left frontal cortical activity.
Article
The study of emotional response inhibition could provide novel insight into dysphoria-related deficits in appetitive and aversive motivational systems. Therefore, dysphoric (N = 21) and nondysphoric (N = 21) participants completed an emotional Go/Nogo paradigm, including the presentation of pleasant, neutral and unpleasant pictures. Behavioral measures [reaction times (RTs), accuracy to Go and Nogo stimuli] and neural correlates (Go/Nogo-N2 and Go/Nogo-P3) of response inhibition were compared between the two groups. Time-frequency analysis was also used as a novel approach to disentangle the multiple processes underlying time-domain ERP data. A reduced Go/Nogo effect for P3 and oscillatory delta activity was found in response to pleasant and neutral, but not unpleasant, stimuli in dysphoric relative to nondysphoric individuals. These findings showed that dysphoric individuals need a reduced and/or less effortful response inhibition to pleasant stimuli, suggesting that dysphoria is characterized by under-engagement of appetitive rather than over-engagement of aversive motivational system.