Science posts

See science posts on page 11 below.

    • 2010
    • Karin J.H. Verweij et al.
    • A genome-wide association study of Cloninger's temperament scales: Implications for the evolutionary genetics of personality
    • Variation in personality traits is 30–60% attributed to genetic influences. Attempts to unravel these genetic influences at the molecular level have, so far, been inconclusive. We performed the first genome-wide association study of Cloninger's temperament scales in a sample of 5117 individuals, in order to identify common genetic variants underlying variation in personality. Participants’ scores on Harm Avoidance, Novelty Seeking, Reward Dependence, and Persistence were tested for association with 1,252,387 genetic markers. We also performed gene-based association tests and biological pathway analyses. No genetic variants that significantly contribute to personality variation were identified, while our sample provides over 90% power to detect variants that explain only 1% of the trait variance. This indicates that individual common genetic variants of this size or greater do not contribute to personality trait variation, which has important implications regarding the gen..
    • 2015
    • Lars Penke et al.
    • The Evolutionary Genetics of Personality Revisited
    • Like all human individual differences, personality traits and intelligence are substantially heritable. From an evolutionary perspective, this poses the question what evolutionary forces maintain their genetic variation. Information about the genetic architecture and associations with evolutionary fitness permit inferences about these evolutionary forces. As our understanding of the genomics of personality and its associations with reproductive success have grown considerably in recent years, it is time to revisit this question. While mutations clearly affect the very low end of the intelligence continuum, individual differences in the normal intelligence range seem to be surprisingly robust against mutations, suggesting that they might have been canalized to withstand such perturbations. Most personality traits, by contrast, seem to be neither neutral to selection nor under consistent directional or stabilizing selection. Instead evidence is in line with balancing selection acting o..
    • 2013
    • Daniel L. Schacter et al.
    • Episodic future thinking and episodic counterfactual thinking: Intersections between memory and decisions
    • This article considers two recent lines of research concerned with the construction of imagined or simulated events that can provide insight into the relationship between memory and decision making. One line of research concerns episodic future thinking, which involves simulating episodes that might occur in one’s personal future, and the other concerns episodic counterfactual thinking, which involves simulating episodes that could have happened in one’s personal past. We first review neuroimaging studies that have examined the neural underpinnings of episodic future thinking and episodic counterfactual thinking. We argue that these studies have revealed that the two forms of episodic simulation engage a common core network including medial parietal, prefrontal, and temporal regions that also supports episodic memory. We also note that neuroimaging studies have documented neural differences between episodic future thinking and episodic counterfactual thinking, inc..
    • 2015
    • Beth L. Parkin et al.
    • Dynamic Network Mechanisms of Relational Integration
    • A prominent hypothesis states that specialized neural modules within the human lateral frontopolar cortices (LFPCs) support “relational integration” (RI), the solving of complex problems using inter-related rules. However, it has been proposed that LFPC activity during RI could reflect the recruitment of additional “domain-general” resources when processing more difficult problems in general as opposed to RI specifically. Moreover, theoretical research with computational models has demonstrated that RI may be supported by dynamic processes that occur throughout distributed networks of brain regions as opposed to within a discrete computational module. Here, we present fMRI findings from a novel deductive reasoning paradigm that controls for general difficulty while manipulating RI demands. In accordance with the domain-general perspective, we observe an increase in frontoparietal activation during challenging problems in general as opposed to R..
    • 2015
    • Paul D. Metzak et. al
    • Functional brain networks involved in reality monitoring
    • Source monitoring refers to the recollection of variables that specify the context and conditions in which a memory episode was encoded. This process involves using the qualitative and quantitative features of a memory trace to distinguish its source. One specific class of source monitoring is reality monitoring, which involves distinguishing internally generated from externally generated information, that is, memories of imagined events from real events. The purpose of the present study was to identify functional brain networks that underlie reality monitoring, using an alternative type of source monitoring as a control condition. On the basis of previous studies on self-referential thinking, it was expected that a medial prefrontal cortex (mPFC) based network would be more active during reality monitoring than the control condition, due to the requirement to focus on a comparison of internal (self) and external (other) source information. Two functional brain networks emerged from ..
    • 2011
    • L. Strathearn
    • Maternal Neglect: Oxytocin, Dopamine and the Neurobiology of Attachment
    • Maternal neglect, including physical and emotional neglect, is a pervasive public health challenge with serious long-term effects on child health and development. I provide an overview of the neurobiological basis of maternal caregiving, aiming to better understand how to prevent and respond to maternal neglect. Drawing from both animal and human studies, key biological systems are identified that contribute to maternal caregiving behaviour, focusing on the oxytocinergic and dopaminergic systems. Mesocorticolimbic and nigrostriatal dopamine pathways contribute to the processing of infant-related sensory cues leading to a behavioural response. Oxytocin may activate the dopaminergic reward pathways in response to social cues. Human neuroimaging studies are summarised that demonstrate parallels between animal and human maternal caregiving responses in the brain. By comparing different patterns of human adult attachment, we gain a clearer understanding of how differences in maternal brai..
    • 2002
    • Michael J. Kane et. al
    • The role of prefrontal cortex in working-memory capacity, executive attention, and general fluid intelligence - An individual-differences perspective
    • We provide an “executive-attention” framework for organizing the cognitive neuroscience research on the constructs of working-memory capacity (WMC), general fluid intelligence, and prefrontal cortex (PFC) function. Rather than provide a novel theory of PFC function, we synthesize a wealth of singlecell, brain-imaging, and neuropsychological research through the lens of our theory of normal individual differences in WMC and attention control (Engle, Kane, & Tuholski, 1999; Engle, Tuholski, Laughlin, & Conway, 1999). Our critical review confirms the prevalent view that dorsolateral PFC circuitry is critical to executive-attention functions. Moreover, although the dorsolateral PFC is but one critical structure in a network of anterior and posterior “attention control” areas, it does have a unique executiveattention role in actively maintaining access to stimulus representations and goals in interference-rich contexts. Our review su..
    • 2003
    • Jean Decety et. al
    • Shared representations between self and other: a social cognitive neuroscience view
    • The abilities to identify with others and to distinguish between self and other play a pivotal role in intersubjective transactions. Here, we marshall evidence from developmental science, social psychology and neuroscience (including clinical neuropsychology) that support the view of a common representation network (both at the computational and neural levels) between self and other. However, sharedness does not mean identicality, otherwise representations of self and others would completely overlap, and lead to confusion. We argue that self-awareness and agency are integral components for navigating within these shared representations. We suggest that within this shared neural network the inferior parietal cortex and the prefrontal cortex in the right hemisphere play a special role in interpersonal awareness.
    • 2008
    • Noah A. Shamosh et. al
    • Individual Differences in Delay Discounting Relation to Intelligence, Working Memory, and Anterior Prefrontal Cortex
    • Lower delay discounting (better self-control) is linked to higher intelligence, but the basis of this relation is uncertain. To investigate the potential role of working memory (WM) processes, we assessed delay discounting, intelligence (g), WM (span tasks, 3-back task), and WM-related neural activity (using functional magnetic resonance imaging) in 103 healthy adults. Delay discounting was negatively correlated with g and WM. WM explained no variance in delay discounting beyond that explained by g, which suggests that processes through which WM relates to delay discounting are shared by g. WM-related neural activity in left anterior prefrontal cortex (Brodmann's area 10) covaried with g, r = .26, and delay discounting, r = -.40, and partially mediated the relation between g and delay discounting. Overall, the results suggest that delay discounting is associated with intelligence in part because of processes instantiated in anterior prefrontal cortex, a region known to support the in..
    • 2011
    • Brandon J. Schmeichel et al.
    • Self-Control at High and Low Levels of Mental Construal
    • The present experiment tested the hypothesis that low-level construals—a known contributor to self-control failure—can improve self-control under some circumstances. In support of this hypothesis, the authors found evidence that low-level construals (relative to high-level construals) improve performance on a measure of response inhibition that requires close attention and responsiveness to the immediate environment—the stop signal task (SST). They also found evidence, consistent with previous research, that high-level construals (relative to low-level construals) improve performance on a modified version of the SST (i.e., the delay SST) that requires both response inhibition and goal maintenance in working memory. These results suggest that, depending on the nature of the task, either low-level construals or high-level construals can enhance self-control.