On feeling in control: a biological theory for individual differences in control perception.
ABSTRACT This review aims to create a cross-disciplinary framework for understanding the perception of control. Although, the personality trait locus of control, the most common measure of control perception, has traditionally been regarded as a product of social learning, it may have biological antecedents as well. It is suggested that control perception follows from the brain's capacity for self regulation, leading to flexible and goal directed behaviours. To this account, a model is presented which spans several levels of analyses. On a behavioural level, control perception may be a corollary of emotion regulation, executive functions, and social cognition. On a neural level, these self-regulatory functions are substantiated in part by the dorsolateral and ventral prefrontal cortex and the anterior cingulate cortex. In addition, a possible role of subcortical-cortical dopamine pathways underlying control perception is discussed.
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ABSTRACT: Recent neuroimaging studies state that meditation increases regional cerebral blood flow (rCBF) in the prefrontal cortex (PFC). The present study employed functional near infrared spectroscopy (fNIRS) to evaluate the relative hemodynamic changes in PFC during a cognitive task. Twenty-two healthy male volunteers with ages between 18 and 30 years (group mean age ± SD; 22.9 ± 4.6 years) performed a color-word stroop task before and after 20 min of meditation and random thinking. Repeated measures ANOVA was performed followed by a post hoc analysis with Bonferroni adjustment for multiple comparisons between the mean values of "During" and "Post" with "Pre" state. During meditation there was an increased in oxy-hemoglobin (ΔHbO) and total hemoglobin (ΔTHC) concentration with reduced deoxy-hemoglobin (ΔHbR) concentration over the right prefrontal cortex (rPFC), whereas in random thinking there was increased ΔHbR with reduced total hemoglobin concentration on the rPFC. The mean reaction time (RT) was shorter during stroop color word task with concomitant reduction in ΔTHC after meditation, suggestive of improved performance and efficiency in task related to attention. Our findings demonstrated that meditation increased cerebral oxygenation and enhanced performance, which was associated with activation of the PFC.Frontiers in Systems Neuroscience 01/2014; 8:252. DOI:10.3389/fnsys.2014.00252
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ABSTRACT: Whether to continue to exploit a source of reward, or to search for a new one of potentially greater value, is a fundamental and underconstrained decision. Recent computational studies of this exploration-exploitation tradeoff have found that variability in exploration across individuals is influenced by a functional polymorphism (Val158Met) in the catechol-O-methyltransferase (COMT) gene, whose protein product degrades synaptically-released dopamine. However, these and other genotype-phenotype associations have rarely been causally tested. To directly test this association and to evaluate additional behavioral characteristics, including perceived locus of control, here we used the COMT inhibitor tolcapone in a randomized, double-blind, counterbalanced, within-subject study of 66 subjects genotyped for the Val158Met allele to assess the hypothesis that reducing COMT enzymatic activity interacts with genotype to increase uncertainty-driven exploration. In keeping with our initial hypothesis, tolcapone led to an increase in exploratory, but not exploitative, behavior in Met/Met rather than Val/Val subjects. Independent of genotype, those subjects with a more external locus of control also showed increases in uncertainty-driven exploration on tolcapone relative to placebo. However, we did not replicate our previous finding that Met/Met subjects show greater exploration at baseline. Together these findings support a model in which exploration is hypothesized to have a dopaminergic basis. Moreover, in keeping with findings in other behavioral and cognitive domains, the response to an increase in presumptively frontal dopamine is dependent upon baseline dopamine tone.Neuropsychopharmacology accepted article preview online, 30 July 2014; doi:10.1038/npp.2014.193.Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 07/2014; 40(2). DOI:10.1038/npp.2014.193 · 8.68 Impact Factor
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ABSTRACT: The tendency to devalue rewards when offered later in time is known as time discounting and, although universal, shows interindividual differences that are proposed to be dependent on an individual’s self-control abilities. In the current study we investigate how the neural correlates of delaying gratification during a time discounting task are associated with individual differences in self-control ability. We assess individual differences on the basis of a self-reported Effortful Control (Adult Temperament Questionnaire) and actual behavior during the task, while controlling for age. Using event-related fMRI, in a population of 41 healthy 18–24-year-old males, choosing for the delayed option activated a network including the inferior frontal gyrus, lateral and ventrolateral prefrontal cortices, and the lateral orbitofrontal cortex. Decisions of individuals who delay more often during the task are associated with more activity in the dorsolateral prefrontal cortex. They furthermore show correlated activity between the inferior frontal gyrus, dorsolateral prefrontal cortex and medial prefrontal regions during decision making compared with individuals who behave more impulsively. Choosing for the earlier reward was not associated with any increases in brain activation compared to choosing for the delayed reward. However, individuals who behave more impulsively show more activation in the medial prefrontal cortex (anterior cingulate cortex, medial frontal gyrus), and no correlated activity with the inferior frontal gyrus. These findings could not be replicated when groups were based on self-report data. We conclude that individual differences in self-control during time discounting may partly result from differential activation of the dorsolateral prefrontal cortex. (PsycINFO Database Record (c) 2014 APA, all rights reserved)Journal of Neuroscience Psychology and Economics 06/2014; 7(2):65. DOI:10.1037/npe0000018