[Show abstract][Hide abstract] ABSTRACT: Poor awareness has been linked to worse recovery and rehabilitation outcomes following moderate-to-severe traumatic brain injury (M/S TBI). The error positivity (Pe) component of the event-related potential (ERP) is linked to error awareness and cognitive control. Participants included 37 neurologically healthy controls and 24 individuals with M/S TBI who completed a brief neuropsychological battery and the error awareness task (EAT), a modified Stroop go/no-go task that elicits aware and unaware errors. Analyses compared between-group no-go accuracy (including accuracy between the first and second halves of the task to measure attention and fatigue), error awareness performance, and Pe amplitude by level of awareness. The M/S TBI group decreased in accuracy and maintained error awareness over time; control participants improved both accuracy and error awareness during the course of the task. Pe amplitude was larger for aware than unaware errors for both groups; however, consistent with previous research on the Pe and TBI, there were no significant between-group differences for Pe amplitudes. Findings suggest possible attention difficulties and low improvement of performance over time may influence specific aspects of error awareness in M/S TBI.
Frontiers in Human Neuroscience 07/2015; 9:397. DOI:10.3389/fnhum.2015.00397 · 3.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An increasing trend in the workplace is for employees to walk on treadmills while working to attain known health benefits; however, the effect of walking on a treadmill during cognitive control and executive function tasks is not well known. We compared the cognitive control processes of conflict adaptation (i.e., congruency sequence effects—improved performance following high-conflict relative to low-conflict trials), post-error slowing (i.e., Rabbitt effect), and response inhibition during treadmill walking (1.5 mph) relative to sitting. Understanding the influence of treadmill desks on these cognitive processes may have implications for worker health and productivity. Sixty-nine individuals were randomized to either a sitting (n = 35) or treadmill-walking condition (n = 34). Groups did not differ in age or body mass index. All participants completed a computerized Eriksen flanker task and a response-inhibition go/no-go task in random order while either walking on a treadmill or seated. Response times (RTs) and accuracy were analyzed separately for each task using mixed model analysis of variance. Separate ANOVAs for RTs and accuracy showed the expected conflict adaptation effects, post-error slowing, and response inhibition effects when collapsed across sitting and treadmill groups (all Fs > 78.77, Ps .38), suggesting no decrements or enhancements in conflict-related control and adjustment processes or response inhibition for those walking on a treadmill versus sitting. We conclude that cognitive control performance remains relatively unaffected during slow treadmill walking relative to sitting.
Frontiers in Psychology 05/2015; 6. DOI:10.3389/fpsyg.2015.00723 · 2.80 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose:
This study compared cognitive (attention, learning, and memory) and typing outcomes during slow treadmill walking or sitting. Seventy-five healthy individuals were randomly assigned to a treadmill walking group (n=37; 23 female) or sitting group (n=38; 17 female).
The treadmill walking group completed a series of tests while walking at 1.5 mph. The sitting group performed the same tests while sitting at a standard desk. Tests performed by both groups included: the Rey Auditory Verbal Learning Test and a modified version of the Paced Auditory Serial Attention Test. In addition, typing performance was evaluated.
Participants in the treadmill walking group performed worse on the Rey Auditory Verbal Learning Test for total learning than the sitting group; the main effect was significant (F(1,73)=4.75, p=0.03, ηp2=0.06); however, short- and long-delay recall performance did not differ between groups (p>0.05). For the Paced Auditory Serial Attention Test, total number of correct responses was lower in the treadmill walking group relative to the sitting group; the main effect was significant (F(1,73)=4.97, p=0.03, ηp2=0.06). The performance of both groups followed the same learning slope (Group x Trial interactions were not significant) for the Rey Auditory Verbal Learning Test and Paced Auditory Serial Attention Test. Individuals in the treadmill walking group performed significantly worse for all measures of typing (p<0.05).
Walking on a treadmill desk may result in a modest difference in total learning and typing outcomes relative to sitting, but those declines may not outweigh the benefit of the physical activity gains from walking on a treadmill.
PLoS ONE 04/2015; 10(4):e0121309. DOI:10.1371/journal.pone.0121309 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Psychometric studies of the ERN, CRN, Pe, and Pc ERPs are increasing. Coherent integration of these results is difficult with classical test theory because the definition of error depends on the measure of reliability. This study used generalizability theory, which extends the ideas of classical test theory, as a framework for evaluating the influence of psychopathology and number of trials on dependability of measurement. Participants included 34 people meeting criteria for major depression, 29 meeting criteria for an anxiety disorder, and 319 controls. For all ERPs, within-person variance was larger than between-person variance across groups, indicating many trials are needed for adequate dependability (at least 13). Slightly fewer trials were needed to achieve adequate dependability in the control group than the pathology groups. Regions of interest had higher dependability than single sensors.
[Show abstract][Hide abstract] ABSTRACT: Few studies have examined neuropsychological functioning among youth with obsessive compulsive disorder (OCD), with inconclusive results. Although methodological differences may contribute to inconsistent findings, clinical factors may also account for differential performance. Symptom dimensions are associated with specific patterns of genetic transmission, comorbidity, and treatment outcome, and may also be uniquely associated with neuropsychological performance. This study examined differences in cognitive sequelae and neurocognitive impairment across symptom dimensions among youth with OCD.
Participants included 93 treatment-seeking youth diagnosed with OCD. A trained clinician administered the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) to parents and children together. Afterward, youth completed a battery of neuropsychological tests that assessed nonverbal memory and fluency, verbal memory, verbal fluency, verbal learning, processing speed, and inhibition/switching.
Across five symptom dimensions, youth exhibiting Hoarding symptoms (χ(2) = 5.21, P = .02) and Symmetry/Ordering symptoms had a greater occurrence of cognitive sequelae (χ(2) = 4.86, P = .03). Additionally, youth with Symmetry/Ordering symptoms had a greater magnitude of cognitive impairment (Mann-Whitney U = 442.50, Z = -2.49, P < .02), with specific deficits identified on nonverbal fluency (P < .01), processing speed (P < .01), and inhibition and switching (P < .02).
Neuropsychological deficits identified in youth with Hoarding and Symmetry/Ordering symptoms may suggest that these symptoms have characteristics specific to neurocognitive impairment. Alternatively, symptoms associated with these dimensions may impede youth's performance during testing. Findings advise neuropsychological testing for youth with symptoms on either of these dimensions when concerns about neuropsychological and/or academic impairment are present.
Depression and Anxiety 12/2014; 31(12). DOI:10.1002/da.22241 · 4.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In religions where God is portrayed as both loving and wrathful, religious beliefs may be a source of fear as well as comfort.
Here, we consider if God’s love may be more effective, relative to God’s wrath, for soothing distress, but less effective
for helping control behavior. Specifically, we assess whether contemplating God’s love reduces our ability to detect and emotionally
react to conflict between one’s behavior and overarching religious standards. We do so within a neurophysiological framework,
by observing the effects of exposure to concepts of God’s love vs punishment on the error-related negativity (ERN)—a neural signal originating in the anterior cingulate cortex that is associated
with performance monitoring and affective responses to errors. Participants included 123 students at Brigham Young University,
who completed a Go/No-Go task where they made ‘religious’ errors (i.e. ostensibly exhibited pro-alcohol tendencies). Reflecting
on God’s love caused dampened ERNs and worse performance on the Go/No-Go task. Thinking about God’s punishment did not affect
performance or ERNs. Results suggest that one possible reason religiosity is generally linked to positive well-being may be
because of a decreased affective response to errors that occurs when God’s love is prominent in the minds of believers.
Social Cognitive and Affective Neuroscience 07/2014; 10(3). DOI:10.1093/scan/nsu096 · 7.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cognitive control theory suggests goal-directed behavior is governed by a dynamic interplay between areas of the prefrontal cortex. Critical to cognitive control is the detection and resolution of competing stimulus or response representations (i.e., conflict). Event-related potential (ERP) research provides a window into the nature and precise temporal sequence of conflict monitoring. We critically review the research on conflict-related ERPs, including the error-related negativity (ERN), Flanker N2, Stroop N450 and conflict slow potential (conflict SP or negative slow wave [NSW]), and provide an analysis of how these ERPs inform conflict monitoring theory. Overall, there is considerable evidence that amplitude of the ERN is sensitive to the degree of response conflict, consistent with a role in conflict monitoring. It remains unclear, however, to what degree contextual, individual, affective, and motivational factors influence ERN amplitudes and how ERN amplitudes are related to regulative changes in behavior. The Flanker N2, Stroop N450, and conflict SP ERPs represent distinct conflict-monitoring processes that reflect conflict detection (N2, N450) and conflict adjustment or resolution processes (N2, conflict SP). The investigation of conflict adaptation effects (i.e., sequence or sequential trial effects) shows the N2 and conflict SP reflect post-conflict adjustments in cognitive control, but the N450 generally does not. Conflict-related ERP research provides a promising avenue for understanding the effects of individual differences on cognitive control processes in healthy, neurologic and psychiatric populations. Comparisons between the major conflict-related ERPs and suggestions for future studies to clarify the nature of conflict-related neural processes are provided.
International journal of psychophysiology: official journal of the International Organization of Psychophysiology 06/2014; 93(3). DOI:10.1016/j.ijpsycho.2014.06.007 · 2.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Although “insistence on sameness” was described as a fundamental feature of autism in Leo Kanner’s original description, research into the underlying mechanisms of rigid behavior has been relatively scant. Understanding how this rigidity develops may inform targets for etiological research and for treatment. In the current study, we used event related potentials (ERP) to explore the neural time course of rule violation in ASD.
Objectives: To investigate ERP signatures in response to rule violation in ASD children and controls. Based on previous research in healthy adults we hypothesized differences in the P300 wave (associated with decision making) and a frontal slow wave from around 500-700ms.
Methods: We used the CyberShape rule violation task developed by Michael Crowley as an analog to the CyberBall social exclusion task. The participant and two virtual partners are supposed to throw to another player indicated by a target shape that matches the shape in the player’s glove. But in alternating blocks of trials, one of the virtual players consistently throws to the “wrong” player.
Thirty four children 11-17 years of age, including 17 diagnosed with ASD and 17 age- and IQ-matched healthy controls, participated in the CyberShape task while being monitored using EGI’s Geodesic128 channel EEG nets and Netstation software. A parent of each participant completed questionnaires regarding dimensional measures of autism symptoms (the Social Responsiveness Scale) and anxiety (the Spence Children’s Anxiety Scale).
Results: No significant difference was found between groups for reaction times. ERPs were analyzed across three conditions: trials in a congruent block where there was no rule violation; trials in an incongruent block where one virtual partner threw against the rules to the other virtual player; and an incongruent condition where one virtual partner threw incorrectly to the participant. A repeated measures ANOVA using a 2 (diagnostic group) x 3 (condition) design wave found a significant main effect (highest activity for incorrect throws to the participant and lowest activity for the congruent trials) but the interaction with group was not significant. Nonetheless, for the ASD group only there was a significant negative correlation (r = -.61) between mean P300 activity and the Mannerisms subscale of the SRS, suggesting that greater repetitive and restricted behavior is associated with decreased P300 response.
A frontal negativity between 300-400ms (faster than we had hypothesized) did not show an overall significant main effect but the group x condition interaction was significant. Visual inspection of the data shows that a clear main effect in the control group was obscured by a lack of differential response to condition.
Conclusions: Our results indicate that the CyberShapes task can reliably elicit neural signatures related to decision making and monitoring, and there is evidence these are related to everyday symptoms of rigid repetitive behavior in ASD. Limited ability to differentiate among different conditions of rule violation or congruence may indicate arise due to inability to extinguish response from the incongruent trials and suggest confusion induced by rule changes in the environment.
2014 International Meeting for Autism Research; 05/2014
[Show abstract][Hide abstract] ABSTRACT: Current literature on cognitive functioning in pregnancy and postpartum is mixed, with most research showing deficits in memory and attention during pregnancy or no difference between pregnant participants and controls with little emphasis on the postpartum period. In the current study, we used a longitudinal controlled design and 42 primarily not depressed participants to compare pregnant women in the third trimester and approximately three months postpartum with matched controls over the same time period on neuropsychological domains including memory, attention, learning, visuospatial, and executive functioning. We also evaluated the role of mood and quality of life as potential moderators of cognitive functioning in pregnancy/postpartum. Results indicated no differences between controls and pregnant/postpartum women on neuropsychological measures at any time points. Self-reported memory difficulties, however, were higher in the pregnant/postpartum women. Pregnant and postpartum women had worse self-reported mood and quality of life than controls. Mood and quality of life slightly moderated specific measures of attention and verbal fluency; however, neither mood nor quality of life moderated overall neuropsychological functioning in either group. Number of previous pregnancies had no effect on the study findings. Results suggest differences in subjective memory complaints, but no differences in objective neuropsychological test results between controls and pregnant/postpartum women who are primarily not diagnosed with depression.
Journal of Clinical and Experimental Neuropsychology 05/2014; 36(5):1-12. DOI:10.1080/13803395.2014.912614 · 2.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Preliminary research suggests neuropsychological deficits in youth with obsessive-compulsive disorder (OCD) similar to those in adults; however, small samples and methodological confounds limit interpretation. We aimed to examine the rates and clinical correlates of cognitive sequelae in youth with OCD, focusing on executive functioning and memory abilities. Youth ages 7–17 years with OCD (N=96) completed a hypothesis-driven neuropsychological battery (including the Rey-Osterreith Complex Figure, California Verbal Learning Test, and subtests of the Delis-Kaplan Executive Function System and Wide Range Assessment of Memory and Learning) that primarily assessed executive functioning, memory and processing speed. Cognitive sequelae were identified in 65% of youth (37% using a more stringent definition of impairment). Magnitude of cognitive sequelae was not associated with OCD severity or age; however, greater neuropsychological impairments were found amongst youth prescribed atypical neuroleptics and those diagnosed with comorbid tic disorders. Comorbidity burden was associated with presence of neuropsychological impairment, but was not specific to any single tests. Findings suggest that the presence of cognitive sequelae is prevalent amongst treatment-seeking youth with OCD. Deficits were found in executive functioning and non-verbal memory performance but these impairments were not associated with OCD severity.
[Show abstract][Hide abstract] ABSTRACT: Research indicates that individuals with autism spectrum disorders (ASD) may have a reduced ability to utilize performance feedback to regulate their behavior; however, it is unclear to what degree alterations in the environmental context affect feedback processing and contribute to the symptoms of ASD. We utilized the observational FRN (oFRN), an event-related potential (ERP) component that putatively indexes feedback processing while observing feedback directed toward another person, to examine the influence of motivational and social demands on feedback processing in ASD. High-density electroencephalogram recordings were collected from 38 youth with ASD and 31 control participants similar on age and IQ while they observed a confederate performing a modified Eriksen Flanker task. Participants were instructed to count the confederate’s errors and were told they would be awarded based on performance: the confederate would either earn points for the participant or herself. Both groups showed robust oFRN activity on traditional scalp-electrode waveforms and waveforms identified using temporospatial principal components analysis. Amplitude of oFRN did not differentiate groups. Results remained non-significant when comparing medicated to non-medicated participants. There were no significant correlations between oFRN amplitudes, autism symptom severity, and anxiety symptoms. Findings suggest that the social context of the task and motivational significance of the confederate’s performance did not limit feedback processing in ASD. Future research in which the context is manipulated further is warranted to determine whether increased environmental complexity influences feedback processing in ASD.
International journal of psychophysiology: official journal of the International Organization of Psychophysiology 04/2014; 92(1). DOI:10.1016/j.ijpsycho.2014.01.009 · 2.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cognitive control theory suggests that goal-directed behavior is governed by a dynamic interplay between areas of the prefrontal cortex. Critical to cognitive control is the detection and resolution of competing stimulus or response representations (i.e., conflict). Event-related potential (ERP) research provides a window into the nature and precise temporal sequence of conflict monitoring. We critically review the research on conflict-related ERPs, including the error-related negativity (ERN), Flanker N2, Stroop N450 and conflict slow potential (conflict SP or negative slow wave [NSW]), and provide an analysis of how these ERPs inform conflict monitoring theory. õOverall, there is considerable evidence that amplitude of the ERN is sensitive to the degree of response conflict, consistent with a role in conflict monitoring. It remains unclear, however, to what degree contextual, individual, affective, and motivational factors influence ERN amplitudes and how ERN amplitudes are related to regulative changes in behavior. The Flanker N2, Stroop N450, and conflict SP ERPs represent distinct conflict-monitoring processes that reflect conflict detection (N2, N450) and conflict adjustment or resolution processes (N2, conflict SP). The investigation of conflict adaptation effects (i.e., sequence or sequential trial effects) shows that the N2 and conflict SP reflect post-conflict adjustments in cognitive control, but the N450 generally does not. Conflict-related ERP research provides a promising avenue for understanding the effects of individual differences on cognitive control processes in healthy, neurologic and psychiatric populations. Comparisons between the major conflict-related ERPs and suggestions for future studies to clarify the nature of conflict-related neural processes are provided.
[Show abstract][Hide abstract] ABSTRACT: Mindfulness meditation is increasingly used in health interventions and may reduce stress and blood pressure. We aimed to investigate the effectiveness of brief mindfulness meditation in reducing cardiovascular reactivity and recovery during a laboratory stressor. We randomly assigned 62 meditation-naïve participants to a mindfulness meditation group or a matched non-mindful listening exercise control group. There were no differences between groups in blood pressure, demographic, or mood variables at baseline. Mindfulness participants showed lower systolic blood pressure following the mindfulness exercise and decreased systolic and diastolic blood pressure reactivity during a speeded math stressor. Specifically, as the stressor progressed, blood pressure in the mindfulness group began to decrease, whereas in the control group, it continued to increase. There were no group differences during recovery. Overall, brief mindfulness meditation reduced cardiovascular reactivity to stress and may be an effective intervention for reducing stress-related blood pressure reactivity.
[Show abstract][Hide abstract] ABSTRACT: The present study examined the clinical correlates of insight among adults with obsessive-compulsive disorder (OCD). One hundred and thirty treatment-seeking adults with a primary diagnosis of OCD, aged 18 to 68 years (mean 31.4 years) participated. Measures of clinical severity, obsessive-compulsive symptom dimensions, anxiety symptoms, depressive symptoms, and ability to resist and control OCD symptoms were obtained. Results indicated that poor insight was positively related to greater OCD symptom severity and poorer ability to resist and control OCD symptoms; this pattern of associations held when insight was examined continuously and categorically (i.e., high versus low insight). Insight was generally not associated with other clinical characteristics, except for a relationship with mental neutralizing behaviors. Insight did not mediate the relationship between the ability to resist and control OCD symptoms and obsessive-compulsive symptom severity. Overall, this study provides further information into the nature and role of insight in adults with OCD.
[Show abstract][Hide abstract] ABSTRACT: The preponderance of research on trial-by-trial recruitment of affective control (e.g., conflict adaptation) relies on stimuli wherein lexical word information conflicts with facial affective stimulus properties (e.g., the face-Stroop paradigm where an emotional word is overlaid on a facial expression). Several studies, however, indicate different neural time course and properties for processing of affective lexical stimuli versus affective facial stimuli. The current investigation used a novel task to examine control processes implemented following conflicting emotional stimuli with conflict-inducing affective face stimuli in the absence of affective words. Forty-one individuals completed a task wherein the affective-valence of the eyes and mouth were either congruent (happy eyes, happy mouth) or incongruent (happy eyes, angry mouth) while high-density event-related potentials (ERPs) were recorded. There was a significant congruency effect and significant conflict adaptation effects for error rates. Although response times (RTs) showed a significant congruency effect, the effect of previous-trial congruency on current-trial RTs was only present for current congruent trials. Temporospatial principal components analysis showed a P3-like ERP source localized using FieldTrip software to the medial cingulate gyrus that was smaller on incongruent than congruent trials and was significantly influenced by the recruitment of control processes following previous-trial emotional conflict (i.e., there was significant conflict adaptation in the ERPs). Results show that a face-only paradigm may be sufficient to elicit emotional conflict and suggest a system for rapidly detecting conflicting emotional stimuli and subsequently adjusting control resources, similar to cognitive conflict detection processes, when using conflicting facial expressions without words.
PLoS ONE 09/2013; 8(9):e75776. DOI:10.1371/journal.pone.0075776 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Individuals with generalized anxiety disorder (GAD) display poor emotional conflict adaptation, a cognitive control process requiring the adjustment of performance based on previous-trial conflict. It is unclear whether GAD-related conflict adaptation difficulties are present during tasks without emotionally-salient stimuli. We examined conflict adaptation using the N2 component of the event-related potential (ERP) and behavioral responses on a Flanker task from 35 individuals with GAD and 35 controls. Groups did not differ on conflict adaptation accuracy; individuals with GAD also displayed intact RT conflict adaptation. In contrast, individuals with GAD showed decreased amplitude N2 principal component for conflict adaptation. Correlations showed increased anxiety and depressive symptoms were associated with longer RT conflict adaptation effects and lower ERP amplitudes, but not when separated by group. We conclude that individuals with GAD show reduced conflict-related component processes that may be influenced by compensatory processes, even in the absence of emotionally-salient stimuli.
[Show abstract][Hide abstract] ABSTRACT: We assessed the psychometric properties, including internal consistency, test-retest reliability, and number of trials needed for stability, for response time (RT) and conflict N2 amplitude measures of conflict adaptation (i.e., sequential trial or Gratton effects). Event-related potentials (ERPs) were obtained from 79 healthy individuals (44 female) during completion of a modified Eriksen flanker task. RTs and N2 amplitude showed reliable conflict adaptation (i.e., previous-trial congruency influenced current-trial measures). Conflict adaptation indices were stable as indicated by reliable internal consistency and 2-week test-retest stability. The number of trials needed for conservative, reliable RT and N2 amplitude measurements was 29 and 30, respectively. This investigation empirically establishes that these conflict adaptation indices represent robust, dependable measures.
[Show abstract][Hide abstract] ABSTRACT: Little is known about the functional impact of putative deficits in white-matter connectivity across the corpus callosum (CC) in individuals with autism spectrum disorders (ASDs). We utilized the temporal sensitivity of event-related potentials to examine the interhemispheric transfer time (IHTT) of basic visual information across the CC in youth with high-functioning ASD relative to healthy controls. We conducted two experiments: a visual letter matching experiment (n = 46) and a visual picture matching experiment, (n = 48) and utilized both electrophysiological (N1 and P1 amplitudes and latencies) and behavioral [response times (RTs), error rates] indices of IHTT. There were no significant group differences on either experiment for RTs, error rates, or N1 and P1 latencies, suggesting that on basic tasks the timing of information flow across the CC may not be altered in high functioning ASD.
Journal of Autism and Developmental Disorders 07/2013; 45(2). DOI:10.1007/s10803-013-1895-7 · 3.06 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Impairments of attention and executive functions are common sequelae of traumatic brain injury (TBI). The anterior cingulate is implicated in conflict-related task performance, such as the Stroop, and is susceptible to TBI-related injury due to its frontal location and proximity to the rough surface of the falx cerebri. We investigated the relationship between cingulate cortex volume and performance on tasks of selective attention and cognitive flexibility (single-trial Stroop and Auditory Consonant Trigrams [ACT]). Participants consisted of 12 adults with severe TBI and 18 controls. T1-weighted volumetric MRI data were analyzed using automated cortical reconstruction, segmentation, parcellation, and volume measurement. Cortical volume reductions were prominent bilaterally in frontal, temporal, and inferior parietal regions. Specific regional reduction of the cingulate cortex was observed only for cortical volume of right caudal anterior cingulate (cACC). The TBI group performed significantly worse than control participants on the Stroop and ACT tasks. Findings suggest that atrophy of the right cACC may contribute to reduced performance on executive function tasks, such as the Stroop and ACT, although this is likely but one node of an extensive brain network involved in these cognitive processes. (JINS, 2013, 19, 1-12).
Journal of the International Neuropsychological Society 07/2013; 19(8):1-12. DOI:10.1017/S135561771300074X · 2.96 Impact Factor