Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
260
result(s) for
"Lewis, Marc D."
Sort by:
Memoirs of an addicted brain : a neuroscientist examines his former life on drugs
A neuroscientist tells the story of his youth spent as a drug addict, while using the specific example of his own story to help explain drug use and addiction in general from a scientific standpoint.
Book
The changing face of emotion: age-related patterns of amygdala activation to salient faces
The present study investigated age-related differences in the amygdala and other nodes of face-processing networks in response to facial expression and familiarity. fMRI data were analyzed from 31 children (3.5–8.5 years) and 14 young adults (18–33 years) who viewed pictures of familiar (mothers) and unfamiliar emotional faces. Results showed that amygdala activation for faces over a scrambled image baseline increased with age. Children, but not adults, showed greater amygdala activation to happy than angry faces; in addition, amygdala activation for angry faces increased with age. In keeping with growing evidence of a positivity bias in young children, our data suggest that children find happy faces to be more salient or meaningful than angry faces. Both children and adults showed preferential activation to mothers’ over strangers’ faces in a region of rostral anterior cingulate cortex associated with self-evaluation, suggesting that some nodes in frontal evaluative networks are active early in development. This study presents novel data on neural correlates of face processing in childhood and indicates that preferential amygdala activation for emotional expressions changes with age.
Journal Article
The biology of desire : why addiction is not a disease
\"Neuroscientist Lewis (Memoirs of an Addicted Brain) presents a strong argument against the disease model of addiction, which is currently predominant in medicine and popular culture alike, and bolsters it with informative and engaging narratives of addicts' lives ... Even when presenting more technical information, Lewis shows a keen ability to put a human face on the most groundbreaking research into addiction. Likewise, he manages to make complex findings and theories both comprehensible and interesting...This book, written with hopeful sincerity, will intrigue both those who accept its thesis and those who do not.\"-- Publishers Weekly.
Book
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.
Journal Article
Developmental change in EEG theta activity in the medial prefrontal cortex during response control
Cognitive control functions continue to improve from infancy until early adulthood, allowing flexible adaptation to a complex environment. However, it remains controversial how this development in cognitive capabilities is mediated by changes in cortical activity: both age-related increases and decreases of mediofrontal neural activity have been observed and interpreted as neural underpinnings of this functional development. To better understand this developmental process, we examined EEG theta activity in the mediofrontal region using a Go/No-go response control task. We found that both pre-stimulus baseline theta-power and theta-power during the response control task, without baseline-correction, decreased with age. Conversely, when task-related theta-power was baseline corrected (using a ratio method), it exhibited a positive developmental trajectory. The age-related theta-power increase was source-localized to the anterior cingulate cortex. This increase in theta activity also partially mediated age-related improvements in response control and was greatest in a condition that demanded greater effort. Theta activity in older children also showed greater temporal reliability across trials as measured by inter-trial phase-coherence. Interestingly, directly subtracting baseline activity from task-related activity did not yield significant developmental effects, which highlights the necessity of separating and contrasting the pre-stimulus baseline with task-related processing in the understanding of neurodevelopmental changes.
•We tested age effects in Go/nogo theta oscillation in a large sample of children.•We found that baseline theta power decreased with age.•Task related theta activity in the medial prefrontal regions increased with age.•The task related theta activity was localized to the anterior cingulate regions.
Journal Article
The Promise of Dynamic Systems Approaches for an Integrated Account of Human Development
After decades of theoretical fragmentation and insularity, a converging explanatory framework based on general scientific principles is an important goal for developmental psychology. Dynamic systems approaches may provide such a framework, using principles of self-organization to explain how novel forms emerge without predetermination and become increasingly complex with development. New trends in traditional theoretical families emphasize systemic, emergent processes, and these can now be explicated with principles of self-organization that apply to all natural systems. Self-organization thus provides a single explanation for the multiple facets of development, integrating diverse developmental viewpoints within a larger scientific perspective.
Journal Article
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.
Journal Article
Dopamine and the Neural \Now\: Essay and Review of \Addiction: A Disorder of Choice\
Rather than view addiction as a disease, Heyman sees it as a choice—one that works like other choices, whereby immediate rewards outshine long-term gains. He rejects neuroscientific explanations of addictive behavior, because he believes they cast it as involuntary or disease-like. I argue that the disease-versus-choice debate creates a false dichotomy: Neuroscience does not have to frame addiction as a disease. Rather, it can help explain how addicts make impulsive choices in the moment and distort appraisal and decision-making habits in the long run. Specifically, the salience of drug-related cues is enhanced by dopamine activity in the ventral striatum, orbitofrontal cortex, and amygdala, due to the intense hedonic impact of repeated drug experiences. Moreover, dopamine-based craving peaks when drug (or alcohol or gambling) rewards become available, in the moment, and this rapid increase in attractiveness preempts rational judgment. Finally, repeated dopamine enhancement modifies brain structures to maximize the appeal of addictive activities, minimize the appeal of competing rewards, and undermine the cognitive capacities necessary to choose between them. I conclude that addiction is not a monolithic state but a recurrent series of choices that permit negotiation, and sometimes cooperation, between immediate and long-range goals.
Journal Article
Neurophysiological mechanisms of emotion regulation for subtypes of externalizing children
Children referred for externalizing behavior problems may not
represent a homogeneous population. Our objective was to assess neural
mechanisms of emotion regulation that might distinguish subtypes of
externalizing children from each other and from their normal age mates.
Children with pure externalizing (EXT) problems were compared with
children comorbid for externalizing and internalizing (MIXED) problems and
with age-matched controls. Only boys were included in the analysis because
so few girls were referred for treatment. We used a go/no-go task with
a negative emotion induction, and we examined dense-array EEG data
together with behavioral measures of performance. We investigated two
event-related potential (ERP) components tapping inhibitory control or
self-monitoring—the inhibitory N2 and error-related negativity
(ERN)—and we constructed source models estimating their cortical
generators. The MIXED children's N2s increased in response to the
emotion induction, resulting in greater amplitudes than EXT children in
the following trial block. ERN amplitudes were greatest for control
children and smallest for EXT children with MIXED children in between, but
only prior to the emotion induction. These results were paralleled by
behavioral differences in response time and performance monitoring. ERP
activity was localized to cortical sources suggestive of the dorsal
anterior cingulate for control children, posterior cingulate areas for the
EXT children, and both posterior cingulate and ventral
cingulate/prefrontal regions for the MIXED children. These findings
highlight different mechanisms of self-regulation underlying externalizing
subtypes and point toward distinct developmental pathways and treatment
strategies.We gratefully acknowledge the
financial support provided by Grant 1 R21 MH67357-01 from the
Developmental Psychopathology and Prevention Research branch of the
National Institute of Mental Health (NIMH), as well as support from the
Canadian Institutes for Health Research (CIHR). We are also grateful for
support provided (to P.D.Z.) by the Canadian Foundation for
Innovation.
Journal Article
Changes in the neural bases of emotion regulation associated with clinical improvement in children with behavior problems
Children's behavior problems may stem from ineffective cortical mechanisms for regulating negative emotions, and the success of interventions may depend on their impact on such mechanisms. We examined neurophysiological markers associated with emotion regulation in children comorbid for externalizing and internalizing problems before and after treatment. We hypothesized that treatment success would correspond with reduced ventral prefrontal activation, and increased dorsomedial prefrontal activation, at the time point of an event-related potential (ERP) associated with inhibitory control. Twenty-seven 8- to 12-year-old children (with usable data) were tested before and after a 14-week community-based treatment program and assessed as to improvement status. Fifteen 8- to 12-year-olds from the normal population (with usable data) were tested over the same interval. All children completed an emotion-induction go/no-go task while fitted with a 128-channel electrode net at each test session. ERP amplitudes, and estimates of cortical activation in prefrontal regions of interest, were measured at the peak of the “inhibitory” N2 and compared between improvers, nonimprovers, and nonclinical children. ERP amplitudes showed no group differences. However, improvers showed an overall reduction in ventral prefrontal activation from pretreatment to posttreatment, bringing them in line with nonclinical children, whereas ventral activation remained high for nonimprovers. Both improvers and nonimprovers showed high dorsal activation relative to nonclinical children. Supplementary analyses indicated that only ventral prefrontal regions, and only within the N2 time window, showed decreased activity from pre- to posttreatment, suggesting changes in regulatory processes rather than in overall emotional arousal. These cortically mediated changes may permit a reduction in the overengaged, rigid style of emotion regulation characteristic of children with behavior problems.
Journal Article