Suzan R. Farris’s scientific contributions

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Publications (7)


Inter-individual variability in respiration during heat (49 °C) relative to neutral (35 °C) scans. The difference between respiration rate during noxious heat (49 °C) and non-noxious neutral (35 °C) stimulation scans was computed for each participant. Negative values (blue) indicate slower breathing during noxious heat scans, and positive values (red) reflect faster respiration during noxious heat scans when compared to neutral scans. Interestingly, half of the study participants (n = 37) breathed slower during noxious heat when compared to neutral scans, and vice versa
Slower breathing is associated with lower pain intensity. (A) Slower respiration rate during noxious heat stimulation is associated with lower pain intensity ratings, r = 0.26, p = 0.03. (B) Slower respiration rate during non-noxious heat stimulation is associated with lower pain intensity ratings, r = 0.28, p = 0.02
Neural correlates of slower breathing and lower pain during noxious stimulation. (A) A linear regression analysis with respiration rate revealed activation in the supramarginal gyrus (SMG, Z > 3.10, cluster-corrected p < 0.05). (B) Higher CBF in SMG is associated with slower respiration rate during noxious heat stimulation (r =  − 0.51, p < 0.001). (C) Higher CBF in SMG is associated with lower pain intensity ratings (r =  − 0.24, p = 0.04)
Neural and Psychological Mechanisms in the Relationship Between Resting Breathing Rate and Pain
  • Article
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July 2023

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105 Reads

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1 Citation

Mindfulness

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Suzan R. Farris

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Fadel Zeidan

Objectives Breathing rate and pain are influenced by a spectrum of cognitive, affective, and physiological interactions. Yet, it is unknown if an individual’s resting breathing rate is associated with pain. Methods Continuous cerebral blood flow (CBF) and respiration rate were collected in 74 healthy participants during innocuous (35 °C) and noxious (49 °C) stimulation. Mindfulness and anxiety were assessed before acquiring perfusion fMRI data. Visual analog scale pain ratings were collected after pain testing. Results Slower resting respiration rate during noxious (r = 0.26, p = 0.03) and innocuous (r = 0.28, p = 0.02) heat was associated with lower pain sensitivity. Analyses of the whole-brain fMRI data revealed that higher CBF in the supramarginal gyrus, a central node of the ventral attention network, was associated with a slower breathing rate during noxious heat (r = − 0.51, p < 0.001) and lower reported pain levels (r = − 0.24, p = 0.04). Higher levels of dispositional mindfulness, but not anxiety (p > 0.20), were associated with slower breathing rate (r = − 0.28, p = 0.02) and lower pain (r = − 0.25, p = 0.03). Conclusions These findings demonstrate that individuals who naturally breathe slower report lower pain and engage unique mechanisms, suggesting the allocation of attention to physical bodily processes.

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Slower Respiration Rate Predicts Lower Pain Sensitivity and Greater Supramarginal Gyrus Activation

May 2022

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19 Reads

Journal of Pain

The subjective experience of pain is driven by multiple physiological and psychological mechanisms supported by a dynamic interplay between low-level afferent input and higher-order cerebral mechanisms. Volitional changes in respiration rate predict changes in pain. However, it is unknown if naturally slower breathing rate is associated with lower pain sensitivity. Further, the brain mechanisms supporting breathing rate during noxious and innocuous stimulation have not been identified. Seventy-four healthy volunteers were administered innocuous (35°C) and noxious heat (Medoc; ten, 12s plateaus of 49°C) to the back of the right calf during pseudocontinuos arterial spin labeling fMRI acquisition (TI = 3 s, TE = 12 ms, TR = 4 s, reps = 66). A visual analogue scale (0 = no pain – 10 = worst pain imaginable) was used to collect pain intensity ratings after each fMRI series. Respiration rate was continuously acquired using a respiratory transducer (Biopac Systems). Linear regression analyses tested the hypothesized relationship between respiration rate and pain sensitivity (SPSS). Standard preprocessing of the functional images included 9 mm spatial smoothing, registration to MNI template and white matter signal regression. A whole-brain analysis examined the between-subjects neural correlates of respiration rate during noxious heat scans (FSL, z>3.1, cluster corrected p<0.05). Slower respiration rate during noxious and innocuous heat predicted lower pain intensity ratings (r = .26, p = 0.03; r = .28, p = .02 respectively). Slower breathing rate was associated with higher cerebral blood flow in the right supramarginal gyrus (SMG) during noxious heat. Individuals that naturally breathed slower during noxious and innocuous stimulation reported lower pain sensitivity. This is supported by stronger activity in the ipsilateral SMG, a region associated with higher somatic-awareness and attention-reorienting towards endogenously-driven stimuli. We propose that individuals that naturally breath slower might engage pain modulatory mechanisms through higher self-awareness.


Slower dispositional respiration is associated with lower pain sensitivity, higher mindfulness and multiple unique neural mechanisms

May 2021

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38 Reads

Journal of Pain

The relationship between non-volitionally controlled breathing and pain remains unknown. The psychological mechanisms supporting this relationship are also poorly characterized. Anxiety and dispositional mindfulness, two antithetical constructs, are postulated to mediate the relationship between pain and respiration. Anxiety increases breathing and pain. In contrast, dispositional mindfulness is associated with lower anxiety and pain. Importantly, the neural correlates of respiration rate have not been identified. Seventy-four pain-free participants were administered the Five Faceted Mindfulness Questionnaire (FFMQ) and the Spielberger State Anxiety Inventory (SAI) before scanning. Two innocuous (35°C) and noxious (49°C; right calf) stimulation series during pseudo-continuous arterial spin labeling functional MRI and continuous respiratory were then acquired. Subjects were instructed to “remain still and close their eyes” and visual analogue scale (0 = “no pain” – 10 = “worst pain imaginable”) pain intensity ratings were collected after each series. Slower respiration was associated with lower pain intensity ratings during noxious (r = .26, p = .03) and innocuous (r = .28, p = .02) stimulation. Higher mindfulness scores were associated with slower respiration (r = -.28, p = .02) and lower pain (r = -.25, p = .03). State anxiety did not significantly co-vary with pain or respiration (ps > .18). When compared to 35°C, 49°C stimulation produced significant activation in the primary somatosensory cortex corresponding to the stimulation site, bilateral thalamus, secondary somatosensory cortex, anterior/posterior insula, and dorsal anterior cingulate cortex (dACC). Slower respiration was associated with greater activation in the subcallosal cortex, subgenual ACC, right-lateralized dorsolateral prefrontal cortex (dlPFC), putamen, anterior insula, and left caudate. Faster breathing was associated with greater activation in respiratory control centers within the pons, medulla, and cerebellum. These findings suggest that individuals who naturally breathe slower report lower pain and engage multiple unique executive-level processes supporting psychological resilience and self-regulation of affect. This work was supported by the National Center for Complementary and Integrative Health (R21-AT007247, F32-AT006949, K99/R00-AT008238, R01-AT009693; F32 AT010843) and the Mind and Life Institute's Francisco J. Varela Award.


(253) Neural Moderators Supporting the Positive Relationship between Resting Breathing Rate and Pain Responses

April 2019

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17 Reads

Journal of Pain

Inter-individual differences in pain are shaped by a myriad of interactions between physiological, cognitive-affective and psychosocial factors. Interestingly, recent findings demonstrate that slow breathing-based manipulations reduce pain. Yet, it is unknown if non-manipulated, resting breathing rate predicts variability in behavioral and neural pain responses. The proposed study, part of a previously published dataset, examined if non-manipulated, slow breathing during noxious (heat = 49°C) and innocuous (neutral = 35°C) heat predicted lower pain. We postulated that subcortical respiration centers (brainstem) would moderate this hypothesized relationship. Seventy-four healthy, pain-free individuals were fitted with a respiratory transducer and administered two neutral and two heat series to the right calf during pseudo-continuous arterial spin labeling fMRI. After each fMRI series, participants provided pain intensity and unpleasantness ratings using a visual analog scale (0 = no pain – 10 = worst pain imaginable). Lower respiration rate was associated with lower pain intensity (r = .29, p = .01) and unpleasantness (r = .25, p = .03) ratings. Compared to innocuous stimulation, noxious heat produced significant activation in the bilateral thalamus, posterior/anterior insula, secondary somatosensory cortices (SII), primary somatosensory cortex (SI) corresponding to the stimulation site, and deactivation of the medial prefrontal (mPFC) and posterior cingulate cortex. Greater superior frontal gyrus and mPFC activation was associated with lower pain unpleasantness ratings. Two separate moderation analyses were conducted on respiration rate and pain intensity and unpleasantness, respectively. There were no significant neural moderators between pain intensity and respiration. High activation of the bilateral SI, contralateral SII, and ipsilateral superior parietal lobe moderated the positive relationship between respiration and pain unpleasantness. This study provides novel evidence that inter-individual differences in breathing predict pain responses and are moderated by brain mechanisms supporting the allocation of attention to intrinsic and extrinsic features of the pain experience.


Brain moderators supporting the relationship between depressive mood and pain

April 2019

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66 Reads

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19 Citations

Pain

Pain and depressive mood commonly exhibit a comorbid relationship. Yet, the brain mechanisms that moderate the relationship between dysphoric mood and pain remain unknown. An exploratory analysis of fMRI, behavioral and psychophysical data was collected from a previous study in seventy-six healthy, non-depressed, and pain-free individuals. Participants completed the Beck Depression Inventory-II (BDI), a measure of negative mood/depressive symptomology and provided pain intensity and pain unpleasantness ratings in response to noxious heat (49°C) during perfusion-based, arterial spin labeled functional magnetic resonance imaging. Moderation analyses were conducted to determine neural mechanisms involved in facilitating the hypothesized relationship between depressive mood and pain sensitivity. Higher BDI-II scores were positively associated with pain intensity (R2 = .10; p = .006) and pain unpleasantness (R2 = .12; p = .003) ratings. There was a high correlation between pain intensity and unpleasantness ratings (r = .94; p < .001), thus brain moderation analyses were focused on pain intensity ratings. Individuals with higher levels of depressive mood exhibited heightened sensitivity to experimental pain. Greater activation in regions supporting the evaluation of pain (ventrolateral prefrontal cortex; anterior insula) and sensory-discrimination (secondary somatosensory cortex; posterior insula) moderated the relationship between higher BDI-II scores and pain intensity ratings. The present study demonstrates that executive-level and sensory-discriminative brain mechanisms play a multimodal role in facilitating the bidirectional relationship between negative mood and pain.


Neural Mechanisms Supporting the Relationship between Dispositional Mindfulness and Pain

July 2018

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175 Reads

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67 Citations

Pain

Inter-individual differences in pain sensitivity vary as a function of interactions between sensory, cognitive-affective and dispositional factors. Trait mindfulness, characterized as the innate capacity to non-reactively sustain attention to the present moment, is a psychological construct that is associated with lower clinical pain outcomes. Yet, the neural mechanisms supporting dispositional mindfulness are unknown. In an exploratory data analysis obtained during a study comparing mindfulness to placebo-analgesia, we sought to determine if dispositional mindfulness is associated with lower pain sensitivity. We also aimed to identify the brain mechanisms supporting the postulated inverse relationship between trait mindfulness and pain in response to noxious stimulation. We hypothesized that trait mindfulness would be associated with lower pain and greater deactivation of the default mode network. Seventy-six, meditation-naïve and healthy volunteers completed the Freiburg Mindfulness Inventory (FMI) and were administered innocuous (35°C) and noxious stimulation (49°C) during perfusion-based functional magnetic resonance imaging. Higher FMI ratings were associated with lower pain intensity (p =.005) and pain unpleasantness ratings (p =.005). Whole brain analyses revealed that higher dispositional mindfulness was associated with greater deactivation of a brain region extending from the precuneus to posterior cingulate cortex (PCC) during noxious heat. These novel findings demonstrate that mindful individuals feel less pain and evoke greater deactivation of brain regions supporting the engagement sensory, cognitive and affective appraisals. We propose that mindfulness and the PCC should be considered as important mechanistic targets for pain therapies.


Table 1 . Participant demographic, FMI, respiration, cerebral blood flow, and heart rate information
Table 2 . Perceived intervention effectiveness ratings (mean SEM) across sessions
Figure 3. Psychophysical pain ratings (mean Ϯ SEM) in MRI Session B. Mindfulness meditation produced greater reductions in both pain intensity (left) and pain unpleasantness (right) compared with placebo. **Mindfulness meditation also was significantly ( p Ͻ 0.05) more effective at reducing pain intensity (left) and pain unpleasantness (right) ratings than sham mindfulness meditation and control conditions. *All cognitive manipulations were significantly ( p Ͻ 0.004) more effective at reducing pain intensity and unpleasantness ratings compared with the control group. 0.24, p Ͻ 0.001). Therefore, in addition to mean intensity normalization antness ( F (3,71) ϭ 0.10, p ϭ 0.962) ratings in response to the of our PCASL data, we first segmented each subject’s anatomical data “heat” series (Fig. 2). into white matter partial volume maps using the FAST algorithm in FSL One participant provided a rating of 0.30 (pain intensity and (Smith et al., 2004) and extracted their respective white matter values. unpleasantness) in response to a “neutral” series. All other sub- We then included each individual’s respective white matter value as a jects provided a “0” to “neutral” series. Therefore, there were no nuisance covariate of no interest in the first-level analyses in MRI Session B (Fox et al., 2005; Restom et al., 2006; Behzadi et al., 2007; Leber, 2010). significant group differences for pain intensity ( F (3,71) ϭ 0.98, p ϭ Subject-to-subject visual inspections of first-level PCASL analyses con- 0.406) or pain unpleasantness ( F (3,71) ϭ 0.98, p ϭ 0.406) ratings firmed that this technique reduced white matter artifacts. in response to the “neutral” series. Analysis of physiological data Post-intervention In all ANOVAs examining physiological data, significant ( p Ͻ 0.05) main Mindfulness meditation produces greater pain relief than pla- effects and interactions were investigated with planned post hoc tests com- cebo and sham mindfulness meditation. paring the percent change in physiological outcomes between the mindfulness meditation and the three comparison groups (Toothaker, 1993; Cohen Pain intensity ratings and Lea, 2004). All groups exhibited a significant change in pain intensity ratings from pre-manipulation to post-manipulation in re- Respiration A 2 ( pre-manipulation rate vs post-manipulation) ϫ 2 (“heat” vs “neu- Fig. sponse 3). to The “heat” significant series ( group F (1,71) ϫ ϭ manipulation 10.06, p ϭ 0.002, interaction ␩ p 2 ϭ 0.12; on tion tral”) rate ϫ 4 in (group) MRI Session mixed-model B. Prior ANOVA work has tested demonstrated for changes in a positive respira- pain intensity ( F (3,71) ϭ 9.96, p Ͻ 0.001, ␩ p 2 ϭ 0.30) was asso- relationship between pain ratings and respiration rate (Grant and Rain- ciated with the significant decrease in pain intensity ratings ville, 2009; Martin et al., 2012). Therefore, a three-factor ANOVA tested during mindfulness meditation ( Ϫ 27%; F (1,16) ϭ 13.00, p ϭ the main effect of group, manipulation, and stimulation level (i.e., 0.002, ␩ p 2 ϭ 0.45), placebo ( Ϫ 11%; F (1,18) ϭ 5.74, p ϭ 0.028, ␩ p 2 “heat,” “neutral”) on respiration rate. Multiple regression analyses were ϭ 0.24), and sham mindfulness meditation ( Ϫ 8%; F (1,19) ϭ performed to determine whether respiration rate predicted changes in 4.67, p ϭ 0.044, ␩ p 2 ϭ 0.20) and the significant pain intensity pain ratings within groups. increase ( ϩ 14%; F (1,18) ϭ 7.52, p ϭ 0.013, ␩ p 2 ϭ 0.30) during Global cerebral blood flow the control condition. There was no significant main effect of In MRI Session B, a 2 ( pre-manipulation vs post-manipulation) ϫ 2 group ( F (3,71) ϭ 1.20, p ϭ 0.315). (“heat” vs “neutral”) ϫ 4 (group) mixed-model ANOVA tested for To interpret the significant manipulation ϫ group interac- changes in global CBF. tion, we calculated and compared the percent change in pain intensity and unpleasantness ratings between the mindfulness Heart rate meditation and comparison groups (Toothaker, 1993). This A 2 ( pre-manipulation vs post-manipulation) ϫ 2 (“heat” vs “neu- approach was used to test the hypothesis that mindfulness tral”) ϫ 4 (group) mixed-model ANOVA tested for changes in heart rate in MRI Session B. meditation would produce greater reductions in pain ratings compared with the comparison groups. Our hypotheses were Results supported because mindfulness-meditation-related pain in- Behavioral findings tensity reductions (Fig. 3) were significantly greater than Pre-intervention placebo analgesia ( p ϭ 0.032), sham mindfulness-meditation- There were no significant pre-intervention differences among related pain relief ( p ϭ 0.030), and the control condition ( p Ͻ groups for pain intensity ( F (3,71) ϭ 0.002, p ϭ 1.00) or unpleas- 0.001). Importantly, all cognitive manipulations significantly 
Figure 4. Brain activations and deactivations associated with the main effect of pain in each group in MRI Session B. Top, In all four groups, there was significant activation in the SI corresponding to the stimulation site, thalamus, cerebellum, midcingulate cortex, anterior/posterior insula, frontal operculum, SII, and SMA. Significant deactivations were detected in the mPFC, PCC/precuneous, and superior (S) frontal gyrus in all four groups. Bottom, Group comparisons revealed significantly greater activation in the left DLPFC in the placebo, sham mindfulness meditation, and control group compared with the mindfulness meditation group. Slice locations correspond to standard stereotaxic space. 
Figure 6. Brain activations and deactivations associated with the main effect of mindfulness meditation and sham mindfulness meditation. Sham mindfulness meditation produced significant activation in the globus pallidus, putamen and right SI of the nose and significant deactivation of the subgenual ACC, PCC, cerebellum and mPFC compared with pre-manipulation. Compared with sham mindfulness meditation, mindfulness meditation produced greater activation in the right putamen/globus pallidus and the PCC. Compared with mindfulness meditation, sham mindfulness meditation was associated with greater activation in the DLPFC, thalamus, PAG, and cerebellum. Conjunction analyses revealed significant overlapping activation in the bilateral putamen and SI corresponding to the nose and deactivation in the mPFC, PCC/precuneous, and cerebellum. Slice locations correspond to standard stereotaxic space.
Mindfulness Meditation-Based Pain Relief Employs Different Neural Mechanisms Than Placebo and Sham Mindfulness Meditation-Induced Analgesia

November 2015

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2,034 Reads

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327 Citations

The Journal of Neuroscience : The Official Journal of the Society for Neuroscience

Unlabelled: Mindfulness meditation reduces pain in experimental and clinical settings. However, it remains unknown whether mindfulness meditation engages pain-relieving mechanisms other than those associated with the placebo effect (e.g., conditioning, psychosocial context, beliefs). To determine whether the analgesic mechanisms of mindfulness meditation are different from placebo, we randomly assigned 75 healthy, human volunteers to 4 d of the following: (1) mindfulness meditation, (2) placebo conditioning, (3) sham mindfulness meditation, or (4) book-listening control intervention. We assessed intervention efficacy using psychophysical evaluation of experimental pain and functional neuroimaging. Importantly, all cognitive manipulations (i.e., mindfulness meditation, placebo conditioning, sham mindfulness meditation) significantly attenuated pain intensity and unpleasantness ratings when compared to rest and the control condition (p < 0.05). Mindfulness meditation reduced pain intensity (p = 0.032) and pain unpleasantness (p < 0.001) ratings more than placebo analgesia. Mindfulness meditation also reduced pain intensity (p = 0.030) and pain unpleasantness (p = 0.043) ratings more than sham mindfulness meditation. Mindfulness-meditation-related pain relief was associated with greater activation in brain regions associated with the cognitive modulation of pain, including the orbitofrontal, subgenual anterior cingulate, and anterior insular cortex. In contrast, placebo analgesia was associated with activation of the dorsolateral prefrontal cortex and deactivation of sensory processing regions (secondary somatosensory cortex). Sham mindfulness meditation-induced analgesia was not correlated with significant neural activity, but rather by greater reductions in respiration rate. This study is the first to demonstrate that mindfulness-related pain relief is mechanistically distinct from placebo analgesia. The elucidation of this distinction confirms the existence of multiple, cognitively driven, supraspinal mechanisms for pain modulation. Significance statement: Recent findings have demonstrated that mindfulness meditation significantly reduces pain. Given that the "gold standard" for evaluating the efficacy of behavioral interventions is based on appropriate placebo comparisons, it is imperative that we establish whether there is an effect supporting meditation-related pain relief above and beyond the effects of placebo. Here, we provide novel evidence demonstrating that mindfulness meditation produces greater pain relief and employs distinct neural mechanisms than placebo cream and sham mindfulness meditation. Specifically, mindfulness meditation-induced pain relief activated higher-order brain regions, including the orbitofrontal and cingulate cortices. In contrast, placebo analgesia was associated with decreased pain-related brain activation. These findings demonstrate that mindfulness meditation reduces pain through unique mechanisms and may foster greater acceptance of meditation as an adjunct pain therapy.

Citations (3)


... Abbreviations: HR, hazard ratio; CI, confidence interval; ACE, adverse childhood experiences a adjusted for age, sex, residents, education, marital status, BMI, smoking, drinking, ADL, IADL, social activity, exercise, number of chronic diseases, Cystatin C, high density lipoprotein cholesterol adulthood and a more closed and vulnerable psychological state. Biologically, chronic physical pain and depressive symptoms may share common neural circuits and brain modulators [31,32]. Furthermore, research suggests that chronic inflammation is a risk factor for depression, and both ACE and physical pain are associated with some level of inflammation [33][34][35][36][37]. Longitudinal studies and meta-analyses evaluating evidence suggest that stress and immune system dysregulation due to ACE exposure are significantly associated with elevated inflammatory biomarkers, with a mechanophysiological response to trauma [38]. ...

Reference:

Longitudinal relationship between adverse childhood experiences and depressive symptoms: the mediating role of physical pain
Brain moderators supporting the relationship between depressive mood and pain
  • Citing Article
  • April 2019

Pain

... Mindfulness trait, or dispositional mindfulness, refers to a stable characteristic of being attentive and aware of the present moment in a non-judgmental manner. Research indicated that higher levels of dispositional mindfulness can reduce negative psychologic outcomes and improve sensory pain processing, as previously demonstrated [13][14][15]. Additionally, among students, higher dispositional mindfulness is linked to better emotional regulation and lower perceived stress, highlighting its role in managing demanding professional environments [16,17]. ...

Neural Mechanisms Supporting the Relationship between Dispositional Mindfulness and Pain
  • Citing Article
  • July 2018

Pain

... Additionally, previous studies have demonstrated the effectiveness of various physical and occupational therapy interventions for managing chronic low back pain, including core stabilization exercises, aquatic therapy, manual therapy, and psychosocial approaches such as cognitive-behavioral therapy (CBT) and yoga. These interventions have shown significant benefits in reducing pain, improving function, and enhancing mental wellbeing [13][14][15][16][17]. Nonetheless, clinical trials on interventions for chronic NSLBP remain insufficient [18]. ...

Mindfulness Meditation-Based Pain Relief Employs Different Neural Mechanisms Than Placebo and Sham Mindfulness Meditation-Induced Analgesia

The Journal of Neuroscience : The Official Journal of the Society for Neuroscience