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1.
Psychol Med ; 53(5): 2085-2094, 2023 04.
Article in English | MEDLINE | ID: mdl-37310337

ABSTRACT

BACKGROUND: Neuropsychopharmacologic effects of long-term opioid therapy (LTOT) in the context of chronic pain may result in subjective anhedonia coupled with decreased attention to natural rewards. Yet, there are no known efficacious treatments for anhedonia and reward deficits associated with chronic opioid use. Mindfulness-Oriented Recovery Enhancement (MORE), a novel behavioral intervention combining training in mindfulness with savoring of natural rewards, may hold promise for treating anhedonia in LTOT. METHODS: Veterans receiving LTOT (N = 63) for chronic pain were randomized to 8 weeks of MORE or a supportive group (SG) psychotherapy control. Before and after the 8-week treatment groups, we assessed the effects of MORE on the late positive potential (LPP) of the electroencephalogram and skin conductance level (SCL) during viewing and up-regulating responses (i.e. savoring) to natural reward cues. We then examined whether these neurophysiological effects were associated with reductions in subjective anhedonia by 4-month follow-up. RESULTS: Patients treated with MORE demonstrated significantly increased LPP and SCL to natural reward cues and greater decreases in subjective anhedonia relative to those in the SG. The effect of MORE on reducing anhedonia was statistically mediated by increases in LPP response during savoring. CONCLUSIONS: MORE enhances motivated attention to natural reward cues among chronic pain patients on LTOT, as evidenced by increased electrocortical and sympathetic nervous system responses. Given neurophysiological evidence of clinical target engagement, MORE may be an efficacious treatment for anhedonia among chronic opioid users, people with chronic pain, and those at risk for opioid use disorder.


Subject(s)
Chronic Pain , Mindfulness , Opioid-Related Disorders , Humans , Analgesics, Opioid/pharmacology , Anhedonia , Chronic Pain/drug therapy , Opioid-Related Disorders/drug therapy , Reward
2.
Prev Med Rep ; 31: 102069, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36483578

ABSTRACT

The U.S. Department of Housing and Urban Development (HUD) required all Public Housing Authorities to become smokefree in July 2018, following an 18-month implementation period that began February 2017. The HUD rule included all combustible tobacco products; e-cigarettes were not included. This purpose of this study is to characterize e-cigarette use overall and initiation after the implementation of the smokefree rule among tobacco users living in public housing. Data were collected from 396 adult (18+ years) current tobacco users at the time of rule implementation residing in the District of Columbia Housing Authority between July 2018 and November 2021. Measures include e-cigarette use, age of initiation, reasons for e-cigarette use, e-cigarette use susceptibility (among non-users), and sociodemographic characteristics. Descriptive and crosstab statistics were calculated to characterize e-cigarette use. Nearly-one-quarter of tobacco users reported lifetime use of e-cigarettes (24 %, n = 95) and 4.8 % (n = 19) indicated past 30-day e-cigarette use. Of the lifetime users, twenty-two (23.2 %) initiated their use after the smoke-free rule went into effect, with only two of those residents indicating they did so because of the rule. Of those who never used an e-cigarette, 23.5 % (n = 70) indicated being curious about e-cigarettes and 10.7 % (n = 40) said they may use e-cigarettes in the next year. Results indicate low use of e-cigarette products and low uptake due to the rule. Few tobacco users who never used e-cigarettes indicated intentions to use. Results suggest that omitting e-cigarettes from the HUD rule has not led to significant use of these products in this sample.

3.
Psychophysiology ; 59(5): e14052, 2022 05.
Article in English | MEDLINE | ID: mdl-35398913

ABSTRACT

Since its beginnings in the early 20th century, the psychophysiological study of human brain function has included research into the spectral properties of electrical and magnetic brain signals. Now, dramatic advances in digital signal processing, biophysics, and computer science have enabled increasingly sophisticated methodology for neural time series analysis. Innovations in hardware and recording techniques have further expanded the range of tools available to researchers interested in measuring, quantifying, modeling, and altering the spectral properties of neural time series. These tools are increasingly used in the field, by a growing number of researchers who vary in their training, background, and research interests. Implementation and reporting standards also vary greatly in the published literature, causing challenges for authors, readers, reviewers, and editors alike. The present report addresses this issue by providing recommendations for the use of these methods, with a focus on foundational aspects of frequency domain and time-frequency analyses. It also provides publication guidelines, which aim to (1) foster replication and scientific rigor, (2) assist new researchers who wish to enter the field of brain oscillations, and (3) facilitate communication among authors, reviewers, and editors.


Subject(s)
Brain , Psychophysiology , Humans , Research Design , Time Factors
4.
Biol Psychiatry ; 91(12): 1070-1078, 2022 06 15.
Article in English | MEDLINE | ID: mdl-35393080

ABSTRACT

BACKGROUND: Opioid misuse is hypothesized to compromise the ability to regulate negative emotions, as manifested through visceral and peripheral physiological signals. However, neurophysiological impairment of top-down cognitive emotion regulation in opioid misuse has not previously been shown. METHODS: Patients with chronic pain who had been taking opioids for 90 days or longer (N = 149; female, n = 98) underwent a negative emotion regulation task with electroencephalography. Participants were instructed to view or reappraise negative images presented for 3 seconds. Using a validated cutoff score on the Current Opioid Misuse Measure, participants were classified as exhibiting aberrant drug-related behavior consistent with opioid misuse (MISUSE+) or as being low risk for opioid misuse (MISUSE-). Participants reported their craving in response to negative emotions over the past week. RESULTS: We observed a group × condition interaction (p = .003) such that the MISUSE- group decreased the late positive potential of the electroencephalography during reappraisal, whereas the MISUSE+ group showed increased late positive potential during reappraisal. This deficit in negative emotion regulation remained significant after controlling for an array of potential confounding variables, including opioid dose, pain, and depression. Heightened late positive potential during reappraisal was associated with more severe opioid craving. CONCLUSIONS: Opioid misuse may occasion top-down deficits in emotional regulation that begin as early as 400 ms after presentation of negative stimuli. It remains unknown whether emotion dysregulation is the cause, correlate, or consequence of opioid misuse. Nonetheless, targeting emotion dysregulation in opioid misuse with reappraisal-focused interventions may represent an important treatment approach.


Subject(s)
Chronic Pain , Emotional Regulation , Opioid-Related Disorders , Analgesics, Opioid/adverse effects , Chronic Pain/drug therapy , Emotions/physiology , Female , Humans
5.
J Racial Ethn Health Disparities ; 9(2): 641-654, 2022 04.
Article in English | MEDLINE | ID: mdl-33620713

ABSTRACT

Every year, most Black Americans report experiencing racial discrimination, which has been shown to have a variety of negative consequences. Aspects of racial identity, particularly holding a positive perception of one's racial group (private regard), may buffer the impact of negative experiences including racial discrimination through differential coping strategy use. The current study (1) examined whether level of private regard impacted the type of coping strategies used across various forms of perceived experiences of racial discrimination and (2) tested for indirect pathways from perceived experiences of racial discrimination to different coping strategy use. Adults (N = 297) from the community who self-identified as Black American/African American completed several questionnaires on Amazon's Mechanical Turk (MTurk). Four-fifths (80%) of participants reported racial discrimination at least once. Racial identity-particularly private regard-was positively associated with active coping strategy use. Furthermore, results from mediation models demonstrated racial identity was an important predictor of coping strategy use, suggesting high private regard has protective effects against racial discrimination. Worry was an especially robust mediator for pathways from racial discrimination to coping strategies. Altogether, results indicate a need for targeted interventions that promote the development of private regard and address worry about racial discrimination among Black American adults.


Subject(s)
Racism , Adaptation, Psychological , Adult , Black or African American , Humans , Surveys and Questionnaires
6.
Psychophysiology ; 59(5): e13907, 2022 05.
Article in English | MEDLINE | ID: mdl-34310712

ABSTRACT

One critical aspect of reward-feedback is the impact of local outcome history-how past experiences with choices and outcomes influences current behavior and neural activity. Yet, prior event-related potential work in this area has been contentious. This study contributes to this field by using time-frequency measures to better isolate constituent processes. Specifically, we identify how theta and delta are differentially sensitive to local outcome history. Participants completed a binary monetary choice task while we collected EEG data. Unbeknownst to them, trial outcomes were manipulated into pre-determined sequences, ranging from one to eight gains or losses in a row. Analyses were arranged by sequence establishment (first 2 trials of a sequence) and continuation (prolonged sequences of 3-8 trials). During the establishment of a sequence, delta activity to gains and losses were virtually identical on the first (change) trial, demonstrating marked divergence only on the second trial. This difference grew throughout the continuation period, as delta activity was sustained with accruing gains but declined with multiple losses. Theta activity, conversely, demonstrated a maximal loss-gain difference on the change trial but was insensitive to the establishment of a new sequence. Differential theta activity between outcomes decreased as sequences continued, with theta activity increasing over accruing gains and remaining stable over losses. Results indicate that delta-gain and theta-loss signals are relatively stable across sequential outcomes. Furthermore, theta is most sensitive to loss-gain differences on the initial change trial, while delta is more sensitive to gain-loss differences with the continuation of a sequence.


Subject(s)
Gambling , Electroencephalography/methods , Evoked Potentials , Feedback , Feedback, Psychological , Humans , Reward
7.
Front Psychol ; 12: 562269, 2021.
Article in English | MEDLINE | ID: mdl-33746811

ABSTRACT

Fraud can cause severe financial losses and affect the physical and mental health of victims. This study aimed to explore the manipulative characteristics of fraudsters and their relationship with other psychological variables. Thirty-four fraudsters were selected from a medium-security prison in China, and thirty-one healthy participants were recruited online. Both groups completed an emotional face-recognition task and self-report measures assaying emotional manipulation, psychopathy, emotion recognition, and empathy. Results showed that imprisoned fraudsters had higher accuracy in identifying fear and surprise faces but lower accuracy in identifying happiness than controls (t = 5.26, p < 0.001; t = 2.38, p < 0.05; t = 3.75, p < 0.001). Significantly lower scores on non-prosocial factors on the Managing the Emotions of Others scale (MEOS) were found for imprisoned fraudsters, relative to controls (t = 3.21, p < 0.01). Imprisoned fraudsters had low scores in the assessment of psychopathy than the control group, especially Factor 1 (t = 2.04, p = 0.05). For empathy, imprisoned fraudsters had significantly higher scores in perspective-taking than controls (t = 2.03, p = 0.05). Correlation analyses revealed that psychopathic traits were positively correlated with non-prosocial factors in both groups. However, the relationships between emotional manipulation and emotional recognition and empathy were not consistent across the groups. The results suggest that fraudsters may pretend to be as prosocial as healthy controls, who had lower antisocial tendencies, normal empathy ability, and would like to manipulate others' emotions positively during social interaction.

8.
Psychophysiology ; 57(7): e13618, 2020 07.
Article in English | MEDLINE | ID: mdl-32478887

ABSTRACT

P3 amplitude reductions, commonly elicited in oddball paradigms, have been associated with both internalizing (e.g., depression and anxiety) and externalizing problems (e.g., substance use, aggression, and impulsivity). Recent factor analytic models have focused on the shared variance between internalizing and externalizing problems as a potentially important separable psychopathology construct (a general psychopathology factor, or p-factor). To assess neurophysiological markers of this shared variance, we examined P3 amplitude to target and novel stimuli in an undergraduate sample with a range of internalizing and externalizing problems. Participants (N = 125) completed a rotated heads visual oddball paradigm, with IAPS pictures serving as infrequent novel stimuli. Results replicated P3 amplitude reduction relative to both target and novel stimuli separately for internalizing and externalizing problems, and found that the shared variance across internalizing and externalizing was significantly related to lower P3 amplitude to novels, targets, and a factor score of target and novel P3 measures. The present results are consistent with the interpretation that a general or shared problem behavior factor accounts for much of the associations between reduced P3 amplitude and internalizing and externalizing problems.


Subject(s)
Attention/physiology , Behavioral Symptoms/physiopathology , Cerebral Cortex/physiology , Personality/physiology , Visual Perception/physiology , Adolescent , Adult , Electroencephalography , Event-Related Potentials, P300 , Female , Humans , Male , Young Adult
9.
Front Hum Neurosci ; 13: 310, 2019.
Article in English | MEDLINE | ID: mdl-31551737

ABSTRACT

Relatively little attention has been paid to the neural basis of superior memory despite its potential in providing important insight into efforts to improve memory in the general population or to offset age-related cognitive decline. The current study reports a rare opportunity to reproduce and isolate specific neural activities directly associated with exceptional memory. To capture the brain processes responsible for superior memory, we returned to a laboratory task and analytic approach used to explore the nature of exceptional memory, namely, digit-span task combined with verbal protocol analysis. One participant with average memory received approximately 50 h of digit-span training and the participant's digit-span increased from normative (8 digits) to exceptional (30 digits). Event-related potentials were recorded while the participant's digit span increased from 19 to 30 digits. Protocol analysis allowed us to identify direct behavioral indices of idiosyncratic encoding processes underlying the superior memory performance. EEG indices directly corresponding to the behavioral indices of encoding processes were identified. The results suggest that the early attention-related encoding processes were reflected in theta and delta whereas the later attention-independent encoding processes were reflected in time-domain slow-wave. This fine-grained approach offers new insights into studying neural mechanism mediating superior memory and the cognitive effort necessary to develop it.

10.
Neuroimage ; 198: 13-30, 2019 09.
Article in English | MEDLINE | ID: mdl-31100431

ABSTRACT

Theta oscillations (4-8 Hz) provide an organizing principle of cognitive control, allowing goal-directed behavior. In adults, theta power over medial-frontal cortex (MFC) underlies conflict/error monitoring, whereas theta connectivity between MFC and lateral-frontal regions reflects cognitive control recruitment. However, prior work has not separated theta responses that occur before and immediately after a motor response, nor explained how medial-lateral connectivity drives different kinds of control behaviors. Theta's role during adolescence, a developmental window characterized by a motivation-control mismatch also remains unclear. As social observation is known to influence motivation, this might be a particularly important context for studying adolescent theta dynamics. Here, adolescents performed a flanker task alone or under social observation. Focusing first on the nonsocial context, we parsed cognitive control into dissociable subprocesses, illustrating how theta indexes distinct components of cognitive control working together dynamically to produce goal-directed behavior. We separated theta power immediately before/after motor responses, identifying behavioral links to conflict monitoring and error monitoring, respectively. MFC connectivity was separated before/after responses and behaviorally-linked to reactive and proactive control, respectively. Finally, distinct forms of post-error control were dissociated, based on connectivity with rostral/caudal frontal cortex. Social observation was found to exclusively upregulate theta measures indexing post-response error monitoring and proactive control, as opposed to conflict monitoring and reactive control. Linking adolescent cognitive control to theta oscillations provides a bridge between non-invasive recordings in humans and mechanistic studies of neural oscillations in animal models; links to social observation provide insight into the motivation-control interactions that occur during adolescence.


Subject(s)
Brain/physiology , Cognition/physiology , Conflict, Psychological , Executive Function/physiology , Motivation/physiology , Peer Influence , Theta Rhythm , Adolescent , Child , Cortical Synchronization , Electroencephalography , Female , Humans , Male
11.
Emotion ; 19(1): 70-83, 2019 Feb.
Article in English | MEDLINE | ID: mdl-29553758

ABSTRACT

Anxiety sensitivity (AS), or the fear of anxious arousal, is a transdiagnostic risk factor predictive of a wide variety of affective disorders. Whereas AS is widely studied via self-report, the neurophysiological correlates of AS are poorly understood. One specific issue this may help resolve is well-established gender differences in mean levels of AS. The current study evaluated late positive potential (LPP) for images designed to target AS during an emotional picture viewing paradigm. Structural equation modeling was used to examine convergent and discriminant validity for self-report AS and the LPP for AS images, considering gender as a potential moderator. Analyses were conducted in an at-risk sample of 251 community adults (M age = 35.47, SD = 15.95; 56.2% female; 53.6% meeting for a primary Axis I anxiety or related disorder). Findings indicated that the AS image LPP was significantly, uniquely associated with self-report AS, controlling for the LPP for unpleasant images, in females only. Mean levels of AS self-report as well as the AS image LPP were higher in females than in males. These findings provide initial support for the AS image LPP as a useful neurophysiological correlate of AS self-report in females. These findings also provide support for a biological cause for gender differences in AS. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Subject(s)
Anxiety/psychology , Emotions/physiology , Evoked Potentials/physiology , Adult , Female , Gender Identity , Humans , Male , Self Report
12.
Psychophysiology ; 55(9): e13195, 2018 09.
Article in English | MEDLINE | ID: mdl-29750361

ABSTRACT

The role of reward context has been investigated as an important factor in feedback processing. Previous work has demonstrated that the amplitude of the feedback negativity (FN) depends on the value of the outcome relative to the range of possible outcomes in a given context, not the objective value of the outcome. However, some research has shown that the FN does not scale with loss magnitude in loss-only contexts, suggesting that some contexts do not show a pattern of context dependence. Methodologically, time-frequency decomposition techniques have proven useful for isolating time-domain ERP activity as separable processes indexed in delta (< 3 Hz) and theta (3-7 Hz). Thus, the current study assessed the role of context in a modified gambling feedback task using time-frequency analysis to better isolate the underlying processes. Results revealed that theta was more context dependent and reflected a binary evaluation of bad versus good outcomes in the gain and even contexts. Delta was more context independent: good outcomes scaled linearly with reward magnitude and good-bad differences scaled with context valence. Our findings reveal that theta and delta are differentially sensitive to context and that context valence may play a critical role in determining how the brain processes feedback.


Subject(s)
Brain Waves/physiology , Cerebral Cortex/physiology , Choice Behavior/physiology , Evoked Potentials/physiology , Feedback, Psychological/physiology , Psychomotor Performance/physiology , Reward , Adolescent , Adult , Female , Humans , Male , Young Adult
13.
Int J Psychophysiol ; 132(Pt B): 203-212, 2018 10.
Article in English | MEDLINE | ID: mdl-29719202

ABSTRACT

The neurophysiological mechanisms involved in the evaluation of performance feedback have been widely studied in the ERP literature over the past twenty years, but understanding has been limited by the use of traditional time-domain amplitude analytic approaches. Gambling outcome valence has been identified as an important factor modulating event-related potential (ERP) components, most notably the feedback negativity (FN). Recent work employing time-frequency analysis has shown that processes indexed by the FN are confounded in the time-domain and can be better represented as separable feedback-related processes in the theta (3-7 Hz) and delta (0-3 Hz) frequency bands. In addition to time-frequency amplitude analysis, phase synchrony measures have begun to further our understanding of performance evaluation by revealing how feedback information is processed within and between various brain regions. The current study aimed to provide an integrative assessment of time-frequency amplitude, inter-trial phase synchrony, and inter-channel phase synchrony changes following monetary feedback in a gambling task. Results revealed that time-frequency amplitude activity explained separable loss and gain processes confounded in the time-domain. Furthermore, phase synchrony measures explained unique variance above and beyond amplitude measures and demonstrated enhanced functional integration between medial prefrontal and bilateral frontal, motor, and occipital regions for loss relative to gain feedback. These findings demonstrate the utility of assessing time-frequency amplitude, inter-trial phase synchrony, and inter-channel phase synchrony together to better elucidate the neurophysiology of feedback processing.


Subject(s)
Cerebral Cortex/physiology , Delta Rhythm/physiology , Electroencephalography Phase Synchronization/physiology , Executive Function/physiology , Feedback, Psychological/physiology , Theta Rhythm/physiology , Adolescent , Adult , Female , Humans , Male , Neuropsychological Tests , Young Adult
14.
Biol Psychol ; 136: 1-12, 2018 07.
Article in English | MEDLINE | ID: mdl-29729300

ABSTRACT

The feedback negativity (FN) event-related potential (ERP) is widely studied during gambling feedback tasks. However, research on FN and anxiety is minimal and the findings are mixed. To clarify these discrepancies, the current study (N = 238) used time-frequency analysis to disentangle overlapping contributions of delta (0-3 Hz) and theta (3-7 Hz) to feedback processing in a clinically anxious sample, with severity assessed through general worry and physiological arousal scales. Greater general worry showed enhanced delta- and theta-FN broadly across both gain and loss conditions, with theta-FN stronger for losses. Regressions indicated delta-FN maintained unique effects, accounted for theta, and explained the blunted time domain FN for general worry. Increased delta was also associated with physiological arousal, but the effects were accounted for by general worry. Broadly, anxiety-related alterations in feedback processing can be explained by an overall heightened sensitivity to feedback as represented by enhanced delta-FN in relation to the general worry facet of anxiety.


Subject(s)
Anxiety/psychology , Delta Rhythm , Feedback, Psychological , Gambling/psychology , Theta Rhythm , Adult , Arousal , Diagnostic and Statistical Manual of Mental Disorders , Electroencephalography , Evoked Potentials , Female , Humans , Male , Middle Aged , Self Report
15.
Int J Psychophysiol ; 128: 70-80, 2018 06.
Article in English | MEDLINE | ID: mdl-29574233

ABSTRACT

A growing body of work suggests that the P300 (P3) event-related potential (ERP) component is better understood as a mixture of task-relevant processes (Polich, 2007). This converges with earlier time-frequency work suggesting that the P3b is primarily composed of centroparietal delta (0.5-3 Hz) and frontocentral theta (3-7 Hz) activity. Within this study (N = 229), we hope to re-affirm these prior ideas and expand upon them in several crucial ways, reassessing how delta and theta contribute to the visual oddball P3b through the lens of several recent decades of additional P3b research. We provide a comprehensive assessment of how theta and delta time-frequency activity contribute to several common variants of the time-domain P3b, specifically measuring the target and non-target P3b, as well as differences between targets and non-targets, target-to-target interval (TTI), and target habituation. Results replicate and extend earlier work indicating that delta and theta account for a majority of variance in both the target and non-target P3b as well as their respective amplitude differences. They also newly indicate that theta and delta activity can have unique contributions to TTI differences and target habituation effects. Results in target habituation particularly demonstrate how time-frequency analyses can disentangle nuanced changes in P3b activity, shedding new light on these complicated phenomena. Findings suggest that delta and theta measures index separable processes occurring during the P3b, and provide additional support for the idea that they index theoretical frontocentral and centroparietal P3 subcomponents.


Subject(s)
Cerebral Cortex/physiology , Delta Rhythm/physiology , Electroencephalography/methods , Event-Related Potentials, P300/physiology , Habituation, Psychophysiologic/physiology , Psychomotor Performance/physiology , Theta Rhythm/physiology , Visual Perception/physiology , Adult , Female , Humans , Male , Young Adult
16.
J Abnorm Psychol ; 127(1): 12-29, 2018 01.
Article in English | MEDLINE | ID: mdl-29369665

ABSTRACT

Distress intolerance (DI), a trait-like individual difference reflective of the inability to endure aversive affective states, is relevant to multiple forms of psychopathology, but its relations to theoretically relevant neurobiological systems have received little attention. Altered cognitive control-related neurobiology has been theorized to underlie individual differences in DI, but little empirical work has been conducted. To test this hypothesis, baseline data from a large community sample with elevated high levels of emotional psychopathology and comorbidity was utilized (N = 256). Participants completed a complex go/no-go task while EEG was recorded, and P2, N2, and P3 amplitudes were measured. Based upon prior findings on the relations between these components and response inhibition, a core cognitive control function, we hypothesized that DI would predict reduced no-go N2 and P3 amplitude while controlling for current anxious/depressive symptom severity (i.e., negative affect). Peak amplitudes from the raw data and principal components analysis were used to quantify amplitude of ERP components. Partially consistent with predictions, high DI was independently associated with reduced no-go N2 peak amplitude in the raw ERP data, and was significantly related to a frontal positivity factor in the N2 time window across no-go and go trials. Contrary to predictions, no relations between DI and the P3 were found. Overall, results support the theorized relevance of cognitive control-linked neurobiology to individual differences in tolerance of distress over and above distress severity itself, and suggest specific relations between DI and alterations in early controlled attention/conflict-monitoring but not response inhibition or response inhibition-related sequelae. (PsycINFO Database Record


Subject(s)
Brain/physiopathology , Executive Function , Personality , Psychomotor Performance , Stress, Psychological , Adult , Electroencephalography , Evoked Potentials , Female , Humans , Individuality , Inhibition, Psychological , Male , Neuropsychological Tests
17.
Clin Neurophysiol ; 129(1): 210-221, 2018 01.
Article in English | MEDLINE | ID: mdl-29197736

ABSTRACT

OBJECTIVE: To better understand the origins of working memory (WM) impairment in schizophrenia we investigated cortical oscillatory activity in people with schizophrenia (PSZ) while they performed a WM task requiring encoding, maintenance, and retrieval/manipulation processes of spatial information. METHODS: We examined time-frequency synchronous energy of cortical source signals that were derived from magnetoencephalography (MEG) localized to cortical regions using WM-related hemodynamic responses and individualized structural head-models. RESULTS: Compared to thirteen healthy controls (HC), twelve PSZ showed performance deficits regardless of WM-load or duration. During encoding, PSZ had early theta and delta event-related synchrony (ERS) deficits in prefrontal and visual cortices which worsened with greater memory load and predicted WM performance. During prolonged maintenance of material, PSZ showed deficient beta event-related desynchrony (ERD) in dorsolateral prefrontal, posterior parietal, and visual cortices. In retrieval, PSZ showed reduced delta/theta ERS in the anterior prefrontal and ventral visual cortices and diminished gamma ERS in the premotor and posterior parietal cortices. CONCLUSIONS: Although beta/gamma cortical neural oscillatory deficits for maintenance/retrieval are evident during WM, the abnormal prefrontal theta-frequency ERS for encoding is most predictive of poor WM in schizophrenia. SIGNIFICANCE: Time-frequency-spatial analysis identified process- and frequency-specific neural synchrony abnormalities underlying WM deficits in schizophrenia.


Subject(s)
Cortical Synchronization , Memory, Short-Term , Schizophrenia/physiopathology , Adult , Brain Waves , Case-Control Studies , Female , Humans , Magnetoencephalography , Male , Middle Aged
18.
Biol Psychol ; 129: 242-252, 2017 10.
Article in English | MEDLINE | ID: mdl-28865935

ABSTRACT

The roles of outcome valence and expectancy in feedback processing have been investigated as important factors modulating event-related potential (ERP) measures including the feedback negativity (FN) and P300, but results have been inconsistent. Recent work from our group has shown that processes underlying the FN and P300 are better represented as separable processes in the theta (3-7Hz) and delta (0-3Hz) ranges using time-frequency analysis. The current study evaluated the modulation of time-domain FN and P300 and time-frequency theta and delta to outcome valence and expectancy in a gambling feedback task paradigm. Results revealed that the FN was sensitive to valence but not expectancy, and that valence effects were driven by loss-sensitive theta and gain-sensitive delta. Alternatively, the P300 was sensitive to the expectedness of outcomes but only for gain trials, and these expectancy differences were explained by time-frequency delta not theta. These results add to a growing body of research showing that time-frequency measures reflect separable processes underlying time-domain components, where theta is more sensitive to primary task features and less sensitive to secondary features while delta is sensitive to primary and more complex, secondary task features.


Subject(s)
Brain/physiology , Evoked Potentials/physiology , Feedback, Psychological/physiology , Adolescent , Electroencephalography , Female , Gambling/physiopathology , Humans , Male , Young Adult
19.
IEEE Trans Biomed Eng ; 64(1): 225-237, 2017 01.
Article in English | MEDLINE | ID: mdl-27093314

ABSTRACT

Functional connectivity (FC), defined as the statistical dependency between distinct brain regions, has been an important tool in understanding cognitive brain processes. Most of the current works in FC have focused on the assumption of temporally stationary networks. However, recent empirical work indicates that FC is dynamic due to cognitive functions. GOAL: The purpose of this paper is to understand the dynamics of FC for understanding the formation and dissolution of networks of the brain. METHOD: In this paper, we introduce a two-step approach to characterize the dynamics of functional connectivity networks (FCNs) by first identifying change points at which the network connectivity across subjects shows significant changes and then summarizing the FCNs between consecutive change points. The proposed approach is based on a tensor representation of FCNs across time and subjects yielding a four-mode tensor. The change points are identified using a subspace distance measure on low-rank approximations to the tensor at each time point. The network summarization is then obtained through tensor-matrix projections across the subject and time modes. RESULTS: The proposed framework is applied to electroencephalogram (EEG) data collected during a cognitive control task. The detected change-points are consistent with a priori known ERN interval. The results show significant connectivities in medial-frontal regions which are consistent with widely observed ERN amplitude measures. CONCLUSION: The tensor-based method outperforms conventional matrix-based methods such as singular value decomposition in terms of both change-point detection and state summarization. SIGNIFICANCE: The proposed tensor-based method captures the topological structure of FCNs which provides more accurate change-point-detection and state summarization.


Subject(s)
Algorithms , Brain Mapping/methods , Cerebral Cortex/physiology , Electroencephalography/methods , Models, Neurological , Nerve Net/physiology , Computer Simulation , Diagnosis, Computer-Assisted/methods , Humans , Reproducibility of Results , Sensitivity and Specificity
20.
Int J Psychophysiol ; 111: 88-97, 2017 01.
Article in English | MEDLINE | ID: mdl-27864029

ABSTRACT

Time-frequency signal processing approaches are well-developed, and have been widely employed for the study of the energy distribution of event-related potential (ERP) data across time and frequency. Wavelet time-frequency transform (TFT) and Cohen's class of time-frequency distributions (TFD) are the most widely used in the field. While ERP TFT approaches have been most extensively developed for amplitude measures, reflecting the magnitude of regional neuronal activity, time-frequency phase-synchrony measures have gained increased utility in recent years for the assessment of functional connectivity. Phase synchrony measures can be used to index the functional integration between regions (interregional), in addition to the consistency of activity within region (intertrial). In this paper, we focus on a particular class of time-frequency distributions belonging to Cohen's class, known as the Reduced Interference Distribution (RID) for quantifying functional connectivity, which we recently introduced (Aviyente et al., 2011). The present report first summarizes common time-frequency approaches to computing phase-synchrony with ERP data in order to highlight the similarities and differences relative to the RID. In previous work, we demonstrated differences between the RID and wavelet approaches to indexing phase-synchrony, and have applied the RID to demonstrate that RID-based time-frequency phase-synchrony measures can index increased functional connectivity between medial and lateral prefrontal regions during control processing, observed in the theta band during the error-related negativity (ERN). Because ERN amplitude measures have been associated with two other widely studied medial-frontal theta components (no-go N2; feedback negativity, FN), the application of the RID phase synchrony measure in the present report extends our previous work with ERN to include theta activity during the no-go N2 (inhibitory processing) and the feedback negativity (FN; loss feedback processing). Findings support the idea that similar medial-lateral prefrontal functional connectivity underlies the ERN, no-go N2, and FN components, and provide initial validation that the proposed RID-based time-frequency phase-synchrony measure can index this activity.


Subject(s)
Electroencephalography Phase Synchronization/physiology , Evoked Potentials/physiology , Executive Function/physiology , Prefrontal Cortex/physiology , Theta Rhythm/physiology , Adult , Humans , Young Adult
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