Science posts

See science posts on page 34 below.

    • 2014
    • Naomi I. Eisenberger
    • Meta-analytic evidence for the role of the anterior cingulate cortex in social pain
    • Since at least the 1930s, when the American physician James Papez highlighted the importance of the cingulate gyrus for emotional processes (Papez, 1937), researchers have been interested in the functions of this region. One issue that has been challenging to disentangle, though, is how specific psychological processes map onto the various subdivisions of the anterior cingulate cortex (ACC). Whereas early lesion studies focused on the role of the dorsal ACC (dACC) in pain experience (Foltz and White, 1962) and affective processes (Tow and Whitty, 1953), later studies from cognitive neuroscientists in the late 1990s and early 2000s focused on the role of the dACC in cognitive processes such as conflict monitoring and error detection, processes that signal the need for cognitive control (Botvinick et al., 2004). Indeed, an influential review at that time suggested that the dACC was primarily involved in cognitive processes whereas the ventral ACC (vACC) was primarily involved in affect..
    • 2011
    • Jessica R. Andrews-Hanna et al.
    • Cognitive Control in Adolescence: Neural Underpinnings and Relation to Self-Report Behaviors
    • Background Adolescence is commonly characterized by impulsivity, poor decision-making, and lack of foresight. However, the developmental neural underpinnings of these characteristics are not well established. Methodology/Principal Findings To test the hypothesis that these adolescent behaviors are linked to under-developed proactive control mechanisms, the present study employed a hybrid block/event-related functional Magnetic Resonance Imaging (fMRI) Stroop paradigm combined with self-report questionnaires in a large sample of adolescents and adults, ranging in age from 14 to 25. Compared to adults, adolescents under-activated a set of brain regions implicated in proactive top-down control across task blocks comprised of difficult and easy trials. Moreover, the magnitude of lateral prefrontal activity in adolescents predicted self-report measures of impulse control, foresight, and resistance to peer pressure. Consistent with reactive compensatory mechanisms to reduced proac..
    • 2011
    • Ruth M. Krebs et al.
    • The Involvement of the Dopaminergic Midbrain and Cortico-Striatal-Thalamic Circuits in the Integration of Reward Prospect and Attentional Task Demands
    • Reward has been shown to promote human performance in multiple task domains. However, an important debate has developed about the uniqueness of reward-related neural signatures associated with such facilitation, as similar neural patterns can be triggered by increased attentional focus independent of reward. Here, we used functional magnetic resonance imaging to directly investigate the neural commonalities and interactions between the anticipation of both reward and task difficulty, by independently manipulating these factors in a cued-attention paradigm. In preparation for the target stimulus, both factors increased activity within the midbrain, dorsal striatum, and fronto-parietal areas, while inducing deactivations in default-mode regions. Additionally, reward engaged the ventral striatum, posterior cingulate, and occipital cortex, while difficulty engaged medial and dorsolateral frontal regions. Importantly, a network comprising the midbrain, caudate nucleus, thalamus, and anter..
    • 2011
    • Kimberly S. Chiew et al.
    • Positive Affect Versus Reward: Emotional and Motivational Influences on Cognitive Control
    • It is becoming increasingly appreciated that affective influences can contribute strongly to goal-oriented cognition and behavior. However, much work is still needed to properly characterize these influences and the mechanisms by which they contribute to cognitive processing. An important question concerns the nature of emotional manipulations (i.e., direct induction of affectively valenced subjective experience) versus motivational manipulations (e.g., delivery of performance-contingent rewards and punishments) and their impact on cognitive control. Empirical evidence suggests that both kinds of manipulations can influence cognitive control in a systematic fashion, but investigations of both have largely been conducted independently of one another. Likewise, some theoretical accounts suggest that emotion and motivation may modulate cognitive control via common neural mechanisms, while others suggest the possibility of dissociable influences. Here, we provide an analysis and synthesi..
    • 2014
    • T. Shiner et al.
    • Dopamine, Salience, and Response Set Shifting in Prefrontal Cortex
    • Dopamine is implicated in multiple functions, including motor execution, action learning for hedonically salient outcomes, maintenance, and switching of behavioral response set. Here, we used a novel within-subject psychopharmacological and combined functional neuroimaging paradigm, investigating the interaction between hedonic salience, dopamine, and response set shifting, distinct from effects on action learning or motor execution. We asked whether behavioral performance in response set shifting depends on the hedonic salience of reversal cues, by presenting these as null (neutral) or salient (monetary loss) outcomes. We observed marked effects of reversal cue salience on set-switching, with more efficient reversals following salient loss outcomes. L-Dopa degraded this discrimination, leading to inappropriate perseveration. Generic activation in thalamus, insula, and striatum preceded response set switches, with an opposite pattern in ventromedial prefrontal cortex (vmPFC). However..
    • 2013
    • Caroline Gurvich et al.
    • Prefrontal and striatal dopamine influence cognitive control: gene-gene and gene-gender interactions.
    • Introduction: The exploration of genetic variations along the dopaminergic pathway provides one avenue to better understand the complex and interacting influences of prefrontal and striatal dopamine on cognition. This study examined the influence of common and functional polymorphisms of the catechol-O-methyltransferase [COMT] gene, the dopamine transporter gene (DAT1) and the dopamine receptor D2 [DRD2] gene on cognitive control in a healthy sample. Methods: A total of 338 healthy adults, selected from an international consortium linked to Brain Research and Integrative Neuroscience (BRAINnet), were genotyped. Cognitive measures were selected to explore attention (sustained attention and switching of attention), working memory and inhibitory control. Interactions between genotypes were explored using Multivariate Analyses of Variance. Gender was also explored as an additional variable given previous research suggesting gender dopamine interactions. Results: Working mem..
    • 2014
    • Barbara J. Weiland et al.
    • Relationship between impulsivity, prefrontal anticipatory activation, and striatal dopamine release during rewarded task performance
    • Impulsivity, and in particular the negative urgency aspect of this trait, is associated with poor inhibitory control when experiencing negative emotion. Individual differences in aspects of impulsivity have been correlated with striatal dopamine D2/D3 receptor availability and function. This multi-modal pilot study used both positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) to evaluate dopaminergic and neural activity, respectively, using modified versions of the monetary incentive delay task. Twelve healthy female subjects underwent both scans and completed the NEO Personality Inventory Revised to assess Impulsiveness (IMP). We examined the relationship between nucleus accumbens (NAcc) dopaminergic incentive/reward release, measured as a change in D2/D3 binding potential between neutral and incentive/reward conditions with [11C]raclopride PET, and blood oxygen level-dependent (BOLD) activation elicited during the anticipation of rewards, measured wi..
    • 2010
    • Michael J Frank et al.
    • Prefrontal and striatal dopaminergic genes predict individual differences in exploration and exploitation
    • The basal ganglia support learning to exploit decisions that have yielded positive outcomes in the past. In contrast, limited evidence implicates the prefrontal cortex in the process of making strategic exploratory decisions when the magnitude of potential outcomes is unknown. Here we examine neurogenetic contributions to individual differences in these distinct aspects of motivated human behavior, using a temporal decision-making task and computational analysis. We show that two genes controlling striatal dopamine function, DARPP-32 (also called PPP1R1B) and DRD2, are associated with exploitative learning to adjust response times incrementally as a function of positive and negative decision outcomes. In contrast, a gene primarily controlling prefrontal dopamine function (COMT) is associated with a particular type of 'directed exploration', in which exploratory decisions are made in proportion to Bayesian uncertainty about whether other choices might produce outcomes that are better ..
    • 2014
    • Set E et al.
    • Dissociable contribution of prefrontal and striatal dopaminergic genes to learning in economic games.
    • Game theory describes strategic interactions where success of players' actions depends on those of coplayers. In humans, substantial progress has been made at the neural level in characterizing the dopaminergic and frontostriatal mechanisms mediating such behavior. Here we combined computational modeling of strategic learning with a pathway approach to characterize association of strategic behavior with variations in the dopamine pathway. Specifically, using gene-set analysis, we systematically examined contribution of different dopamine genes to variation in a multistrategy competitive game captured by (i) the degree players anticipate and respond to actions of others (belief learning) and (ii) the speed with which such adaptations take place (learning rate). We found that variation in genes that primarily regulate prefrontal dopamine clearance--catechol-O-methyl transferase (COMT) and two isoforms of monoamine oxidase--modulated degree of belief learning across individuals. In cont..
    • 2009
    • James F. Cavanagh et al.
    • Prelude to and Resolution of an Error: EEG Phase Synchrony Reveals Cognitive Control Dynamics during Action Monitoring
    • Error-related activity in the medial prefrontal cortex (mPFC) is thought to work in conjunction with lateral prefrontal cortex (lPFC) as a part of an action-monitoring network, where errors signal the need for increased cognitive control. The neural mechanism by which this mPFC–lPFC interaction occurs remains unknown. We hypothesized that transient synchronous oscillations in the theta range reflect a mechanism by which these structures interact. To test this hypothesis, we extracted oscillatory phase and power from current–source–density-transformed electroencephalographic data recorded during a Flanker task. Theta power in the mPFC was diminished on the trial preceding an error and increased immediately after an error, consistent with predictions of an action-monitoring system. These power dynamics appeared to take place over a response-related background of oscillatory theta phase coherence. Theta phase synchronization between FCz (mPFC) and F5/6 (lPFC) sites was..

Related

You might be interested in.