Biomedical subjects

Marc D Lewis

Publications and source records attributed to Marc D Lewis.

8 recordsLinked to original sources

PubMed2006

A state space analysis of emotion and flexibility in parent-child interactions.

Negative emotion has been shown to reduce flexibility in cognition and behavior. We examined interpersonal flexibility during negative emotional episodes within parent-child interactions. Fifty-five mothers and early-adolescent daughters were observed during a positive discussion, a negative (conflict) discussion, and another positive discussion. Codes of moment-to-moment changes in emotion expression were used to create state space grids from which measures of emotional valence and flexibility were derived. As expected, mean flexibility was lowest during the conflict discussion when negative emotion peaked, suggesting that interpersonal flexibility decreases with increasing negative emotion. Sub-groups identified as low or high in stress were also compared. Dyads with girls reporting more stressful events showed lower flexibility during the first positive discussion. However, dyads expressing more negative emotion during the conflict discussion were also more flexible, suggesting that flexible dyadic styles permit more negative emotion. These individual difference findings are discussed in terms of the suppression versus expression of negative emotions.

Adult↗

PubMed2006

Neurophysiological correlates of emotion regulation in children and adolescents.

Psychologists consider emotion regulation a critical developmental acquisition. Yet, there has been very little research on the neural underpinnings of emotion regulation across childhood and adolescence. We selected two ERP components associated with inhibitory control-the frontal N2 and frontal P3. We recorded these components before, during, and after a negative emotion induction, and compared their amplitude, latency, and source localization over age. Fifty-eight children 5-16 years of age engaged in a simple go/no-go procedure in which points for successful performance earned a valued prize. The temporary loss of all points triggered negative emotions, as confirmed by self-report scales. Both the frontal N2 and frontal P3 decreased in amplitude and latency with age, consistent with the hypothesis of increasing cortical efficiency. Amplitudes were also greater following the emotion induction, only for adolescents for the N2 but across the age span for the frontal P3, suggesting different but overlapping profiles of emotion-related control mechanisms. No-go N2 amplitudes were greater than go N2 amplitudes following the emotion induction at all ages, suggesting a consistent effect of negative emotion on mechanisms of response inhibition. No-go P3 amplitudes were also greater than go P3 amplitudes and they decreased with age, whereas go P3 amplitudes remained low. Finally, source modeling indicated a developmental decline in central-posterior midline activity paralleled by increasing activity in frontal midline regions suggestive of the anterior cingulate cortex. Negative emotion induction corresponded with an additional right ventral prefrontal or temporal generator beginning in middle childhood.

Adolescent↗

PubMed2005

Neural correlates of cognitive control in childhood and adolescence: disentangling the contributions of age and executive function.

Dense-array (128-channel) electroencephalography (EEG) was used to record event-related potentials (ERPs) from 33 participants between 7 and 16 years of age while they performed a Go/Nogo task. The frontal (Nogo) N2 component of the ERP was taken as an index of cognitive control, and examined in relation to both age and independent assessments of executive function (EF), including the Iowa Gambling Task (IGT), the Stroop task, a delay discounting task, and backward digit span. Better performance on the IGT and the Stroop task was associated with smaller N2 amplitudes, over and above effects of age. N2 latencies decreased with age but were not predicted by EF. Source modeling of the N2 revealed neural generators in areas suggestive of cingulate cortex and orbitofrontal cortex, and the locations of these generators varied systematically with EF (IGT and Stroop task): the cingulate generator was more anterior for good EF participants at all ages; the orbitofrontal generator was relatively left lateralized for younger and for poorer EF participants. Taken together, these findings suggest that age-related decreases in N2 amplitude, but not N2 latency, reflect the development of cognitive control and cannot be attributed solely to incidental changes that may affect assessments of the N2 (e.g., increases in skull thickness). Functionally relevant decreases in N2 amplitude may reflect changes in the regions of cortex giving rise to the N2.

Adolescent↗

PubMed2005

Bridging emotion theory and neurobiology through dynamic systems modeling.

Efforts to bridge emotion theory with neurobiology can be facilitated by dynamic systems (DS) modeling. DS principles stipulate higher-order wholes emerging from lower-order constituents through bidirectional causal processes--offering a common language for psychological and neurobiological models. After identifying some limitations of mainstream emotion theory, I apply DS principles to emotion-cognition relations. I then present a psychological model based on this reconceptualization, identifying trigger, self-amplification, and self-stabilization phases of emotion-appraisal states, leading to consolidating traits. The article goes on to describe neural structures and functions involved in appraisal and emotion, as well as DS mechanisms of integration by which they interact. These mechanisms include nested feedback interactions, global effects of neuromodulation, vertical integration, action-monitoring, and synaptic plasticity, and they are modeled in terms of both functional integration and temporal synchronization. I end by elaborating the psychological model of emotion-appraisal states with reference to neural processes.

Adaptation, Psychological↗

PubMed2004

The role of the orbitofrontal cortex in normally developing compulsive-like behaviors and obsessive-compulsive disorder.

Mounting evidence concerning obsessive-compulsive disorders points to abnormal functioning of the orbitofrontal cortices. First, patients with obsessive-compulsive disorder (OCD) perform poorly on tasks that rely on response suppression/motor inhibition functions mediated by the orbitofrontal cortex relative to both normal and clinical controls. Second, patients with OCD exhibit functional hyperactivity in lateral orbitofrontal and related structures corresponding with symptom severity. In this article, we compare these neurocognitive correlates of OCD with the executive and neural underpinnings of "compulsive-like" behaviors that are common in normal childhood. We discuss the phenomenology and natural history of normative compulsive-like behaviors as well as the behavioral, emotional, and cognitive continuities between typical and pathological obsessive-compulsive behaviors. We then examine associations between children's executive performance deficits and their observed compulsive-like characteristics. We relate these patterns to executive deficits shown by adults with OCD. Finally, we speculate on the developmental neurobiology of children's compulsive-like behaviors, with particular attention to orbitofrontal functions including behavioral and emotional regulation, and we suggest similarities and differences with the neurobiology of OCD. In making these comparisons, we hope to open a dialogue between researchers who study underlying brain pathologies associated with OCD and those who explore the neurocognitive bases of normal development.

Adolescent↗

PubMed2004

Trouble ahead: predicting antisocial trajectories with dynamic systems concepts and methods.

This paper reviews and evaluates a set of studies that utilize dynamic systems (DS) principles, and in two cases dynamic systems methods, for predicting antisocial development and other behavioral outcomes. I suggest that the emphasis of DS approaches on process and nonlinear causation is very different from the emphasis in developmental psychopathology on prediction, yet the marriage of these approaches is necessary to capture the complex interactions that give rise to problematic trajectories. The studies reviewed do indeed uncover predictive relations that would have been difficult to conceptualize or impossible to find using more traditional strategies. In discussing these studies. I suggest DS interpretations of emerging individual differences, phase-specific change, sleeper effects, mediating variables, and behavioral rigidity versus malleability, in the context of developmental prediction. I also discuss the advantages of moving from DS concepts to DS methods in clinical-developmental research.

Conduct Disorder↗

PubMed2004

Reorganization in coping behavior at 1 1/2 years: dynamic systems and normative change.

By the age of 1 year toddlers demonstrate distinct coping habits for dealing with frustration. However, these habits may be open to change and reorganization at subsequent developmental junctures. We investigated change in coping habits at 18-20 months, a normative age for major advances in social cognition, focusing on the dynamic systems principles of fluctuation and novelty at transitions. Specifically, we asked whether month-to-month fluctuation, novel behavioral habits and real-time variability increased at the age of a normative transition, despite individual differences in the content of behavior. Infants were given frustrating toys while their mothers sat nearby without helping, on monthly visits at 14-25 months (before, during and after the hypothesized transition). State space grids representing patterns of behavioral durations were constructed for each episode and compared over age. As predicted, month-to-month fluctuation in grid patterns increased temporarily between 17 and 20 months, partly independently of a concurrent peak in distress, and new behavioral habits replaced old ones at the same age. Coping habits changed differently for high-and low-distressed toddlers. However, changes in real-time variability did not generally meet our expectations.

Adaptation, Psychological↗

PubMedDate not supplied

Emotion regulation in the brain: conceptual issues and directions for developmental research.

Emotion regulation cannot be temporally distinguished from emotion in the brain, but activation patterns in prefrontal cortex appear to mediate cognitive control during emotion episodes. Frontal event-related potentials (ERPs) can tap cognitive control hypothetically mediated by the anterior cingulate cortex, and developmentalists have used these to differentiate age, individual, and emotion-valence factors. Extending this approach, the present article outlines a research strategy for studying emotion regulation in children by combining emotion induction with a go/no-go task known to produce frontal ERPs. Preliminary results indicate that medial-frontal ERP amplitudes diminish with age but become more sensitive to anxiety, and internalizing children show higher amplitudes than noninternalizing children, especially when anxious. These results may reflect age and individual differences in the effortful regulation of negative emotion.

Brain↗