Science posts

See science posts on page 13 below.

    • 2014
    • Iroise Dumontheil et al.
    • Preliminary investigation of the influence of dopamine regulating genes on social working memory
    • Working memory (WM) refers to mental processes that enable temporary retention and manipulation of information, including information about other people (“social working memory”). Previous studies have demonstrated that nonsocial WM is supported by dopamine neurotransmission. Here, we investigated in 131 healthy adults whether dopamine is similarly involved in social WM by testing whether social and nonsocial WM are influenced by genetic variants in three genes coding for molecules regulating the availability of dopamine in the brain: catechol-O-methyltransferase (COMT), dopamine active transporter (DAT), and monoamine-oxidase A (MAOA). An advantage for the Met allele of COMT was observed in the two standard WM tasks and in the social WM task. However, the influence of COMT on social WM performance was not accounted for by its influence on either standard WM paradigms. There was no main effect of DAT1 or MAOA, but a significant COMT x DAT1 interaction on social WM perform..
    • 2004
    • Simon Baron-Cohen et al.
    • The Empathy Quotient: An Investigation of Adults with Asperger Syndrome or High Functioning Autism, and Normal Sex Differences
    • Empathy is an essential part of normal social functioning, yet there are precious few instruments for measuring individual differences in this domain. In this article we review psychological theories of empathy and its measurement. Previous instruments that purport to measure this have not always focused purely on empathy. We report a new self-report questionnaire, the Empathy Quotient (EQ), for use with adults of normal intelligence. It contains 40 empathy items and 20 filler/control items. On each empathy item a person can score 2, 1, or 0, so the EQ has a maximum score of 80 and a minimum of zero. In Study 1 we employed the EQ with n = 90 adults (65 males, 25 females) with Asperger Syndrome (AS) or high-functioning autism (HFA), who are reported clinically to have difficulties in empathy. The adults with AS/HFA scored significantly lower on the EQ than n = 90 (65 males, 25 females) age-matched controls. Of the adults with AS/HFA, 81% scored equal to or fewer than 30 points out of ..
    • 2015
    • Ulrike Basten et al.
    • Where smart brains are different: A quantitative meta-analysis of functional and structural brain imaging studies on intelligence
    • Individual differences in general intelligence have been associated with differences in brain structure and function. The currently most popular theory of the neural bases of intelligence – the Parieto-Frontal Integration Theory of Intelligence (P-FIT) – describes a network of frontal and parietal brain regions as the main neural basis of intelligence. Here, we put the theory to an empirical test by conducting voxel-based quantitative meta-analyses of 12 structural and 16 functional human brain imaging studies, testing for statistically significant spatial convergence across studies. We focused our analyses on studies reporting associations between individual differences in intelligence (as assessed by established tests of psychometric intelligence) and either (a) brain activation during a cognitive task (functional meta-analysis) or (b) amount of grey matter as assessed by voxel-based morphometry (structural meta-analysis). The functional meta-analysis resulted in eight ..
    • 2014
    • Daniella Laureiro-Martínez et al.
    • Understanding the exploration–exploitation dilemma: An fMRI study of attention control and decision-making performance
    • This paper studies the cognitive processes that enable decision makers to switch between exploitation and exploration. We use functional magnetic resonance imaging (fMRI) in a sample of expert decision makers to make two main contributions. First, we identify and contrast the specific brain regions and cognitive processes associated with exploitation and exploration decisions. Exploitation activates regions associated with reward seeking, which track and evaluate the value of current choices, while exploration relies on regions associated with attentional control, tracking the value of alternative choices. Second, we propose and test the idea that stronger activation of the brain circuits related to attentional control allows individuals to achieve better decision-making performance as a result. We discuss the implications of these results for strategic management research and practice.
    • 2015
    • Hyeon-Ae Jeon et al.
    • Degree of automaticity and the prefrontal cortex
    • The dorsolateral prefrontal cortex (PFC), with more anterior areas [Brodmann area (BA) 45, 47, and 10], has been known to be activated as cognitive hierarchy increases. However, this does not hold for highly automatic processes such as first language (L1), where the posterior region (BA 44) is known as the key area for the processing of complex linguistic hierarchy. Discussing this disparity, we propose that the degree of automaticity (DoA) is a crucial factor for the framework of functional mapping in the PFC: the posterior-to-anterior gradient system for more controlled processes and the posterior-confined system for automatic processes. We support this view with previous findings and provide a new perspective on the functional organization of the PFC.
    • 2008
    • Cools R
    • Role of dopamine in the motivational and cognitive control of behavior.
    • Brain dopamine has often been implicated in impulsive and/or inflexible behaviors, which may reflect failures of motivational and/or cognitive control. However, the precise role of dopamine in such failures of behavioral control is not well understood, not least because they implicate paradoxical changes in distinct dopamine systems that innervate dissociable neural circuits. In addition, there are large individual differences in the response to dopaminergic drugs with some individuals benefiting from and others being impaired by the same drug. This complicates progress in the understanding of dopamine's role in behavioral control processes, but also provides a major problem for neuropsychiatry, where some individuals are disproportionately vulnerable to the adverse effects of dopamine-enhancing drugs on motivation and cognition. Recent progress is reviewed from cognitive and behavioral neuroscience research on motivation and cognitive control, which begins to elucidate the factors t..
    • 2007
    • Xavier Caldú et al.
    • Impact of the COMT Val108/158 Met and DAT genotypes on prefrontal function in healthy subjects
    • Two limiting factors of dopamine activity are the catechol-o-methyltransferase (COMT) and the dopamine transporter (DAT), which terminate dopamine activity by degradation and uptake, respectively. Genetic variants of COMT and DAT have been related to the enzymatic activity and protein availability, respectively. The Met allele of the COMT Val108/158 Met polymorphism has been associated to lower enzymatic activity and the 9-repeat allele of the DAT 40 base-pair (bp) variable number of tandem repeat (VNTR) polymorphism has been related to lower protein availability. Genotypes for COMT and DAT were determined in a sample of 75 healthy subjects, who underwent functional magnetic resonance imaging (fMRI) while performing an N-back task. To further assess the effects of the genotypes on cognition, subjects were administered the Wisconsin Card Sorting Test (WCST) and the Continuous Performance Test (CPT). Analysis of fMRI data revealed an additive effect of these two genes on brain activati..
    • 2015
    • Wen-Dong Li et al.
    • A mixed blessing? Dual mediating mechanisms in the relationship between dopamine transporter gene DAT1 and leadership role occupancy
    • Trait theories of leadership have documented the role of individual characteristics in affecting leadership. Twin studies have further revealed significant genetic effects on leadership role occupancy. In the era of genomics, the current research examines how a dopamine transporter gene, DAT1, is involved in genetic influences on leadership role occupancy. Study 1 found DAT1 10-repeat allele to negatively relate to proactive personality, which in turn was positively associated with leadership role occupancy. The negative indirect effect was significant, but the overall relationship between this gene and leadership was not. In addition to replicating Study 1's findings using a nationally representative sample, Study 2 revealed another countervailing mechanism: DAT1 was positively related to (moderate) rule breaking, which was positively associated with leadership role occupancy. Consistent findings across the two studies suggest that the pathways linking specific genes to leadership a..
    • 2015
    • Jan-Emmanuel De Neve et al.
    • Born to lead? A twin design and genetic association study of leadership role occupancy
    • We address leadership emergence and the possibility that there is a partially innate predisposition to occupy a leadership role. Employing twin design methods on data from the National Longitudinal Study of Adolescent Health, we estimate the heritability of leadership role occupancy at 24%. Twin studies do not point to specific genes or neurological processes that might be involved. We therefore also conduct association analysis on the available genetic markers. The results show that leadership role occupancy is associated with rs4950, a single nucleotide polymorphism (SNP) residing on a neuronal acetylcholine receptor gene (CHRNB3). We replicate this family-based genetic association result on an independent sample in the Framingham Heart Study. This is the first study to identify a specific genotype associated with the tendency to occupy a leadership position. The results suggest that what determines whether an individual occupies a leadership position is the complex product of gene..
    • 2011
    • Noudoost B et al.
    • Control of visual cortical signals by prefrontal dopamine.
    • The prefrontal cortex is thought to modulate sensory signals in posterior cortices during top-down attention, but little is known about the underlying neural circuitry. Experimental and clinical evidence indicate that prefrontal dopamine has an important role in cognitive functions, acting predominantly through D1 receptors. Here we show that dopamine D1 receptors mediate prefrontal control of signals in the visual cortex of macaques (Macaca mulatta). We pharmacologically altered D1-receptor-mediated activity in the frontal eye field of the prefrontal cortex and measured the effect on the responses of neurons in area V4 of the visual cortex. This manipulation was sufficient to enhance the magnitude, the orientation selectivity and the reliability of V4 visual responses to an extent comparable with the known effects of top-down attention. The enhancement of V4 signals was restricted to neurons with response fields overlapping the part of visual space affected by the D1 receptor manipu..