Does stimulus complexity determine whether working memory storage relies on prefrontal or sensory cortex?

Traditionally, working and short-term memory (WM/STM) have been believed to rely on storage systems located in prefrontal cortex (PFC). However, recent experimental and theoretical efforts have suggested that, in many cases, sensory or other task-relevant cortex is the actual storage substrate for WM/STM. What factors determine whether a given WM/STM task relies on PFC or sensory cortex? In the present article, we outline recent experimental findings and suggest that the dimensionality or complexity of the to-be-remembered property or properties of a stimulus can be a determining factor.     

Children's 5-HTTLPR genotype moderates the link between maternal criticism and attentional biases specifically for facial displays of anger

Theorists have proposed that negative experiences in childhood may contribute to the development of experience-specific information-processing biases, including attentional biases. There are also clear genetic influences on cognitive processes, with evidence that polymorphisms in specific candidate genes may moderate the impact of environmental stress on attentional biases (e.g., a functional polymorphism in the serotonin transporter gene; 5-HTTLPR). In the current study, we tested a gene×environment (G×E) model of risk for attentional biases. We hypothesised that children whose mothers exhibit high levels of expressed emotion criticism (EE-Crit) would display attentional biases specifically for angry, but not happy or sad, faces, and that this link would be stronger among children carrying one or two copies of the 5-HTTLPR short allele than among those homozygous for the long allele. Results generally supported these hypotheses, though we found that carriers of the 5-HTTLPR short allele who also had a critical mother exhibited attentional avoidance of angry faces rather than preferential attention.     

Posttraumatic stress, difficulties in emotion regulation, and coping-oriented marijuana use

In an effort to better understand factors that may explain prior findings of a positive relation between posttraumatic stress symptom severity and coping-oriented marijuana use motivation, the present study tested whether the association between posttraumatic stress symptom severity and marijuana use coping motives is mediated by difficulties in emotion regulation. Participants were 79 (39 women; M(age) = 22.29 years, SD = 6.99) community-recruited adults who reported (1) lifetime exposure to at least one posttraumatic stress disorder Criterion A traumatic event and (2) marijuana use in the past 30 days. Results indicated that difficulties in emotion regulation, as indexed by the Difficulties in Emotion Regulation Scale (Gratz & Roemer, 2004), fully mediated the association between posttraumatic stress symptom severity and marijuana use coping motives. Implications for the treatment of co-occurring posttraumatic stress and marijuana use are discussed.     

Serotonin Transporter Genotype Moderates the Link Between Children’s Reports of Overprotective Parenting and Their Behavioral Inhibition

The goal of the current study was to examine environmental and genetic correlates of children’s levels of behavioral inhibition (BI). Participants were 100 mother child pairs drawn from the community who were part of a larger study of the intergenerational transmission of depression. Results indicated that higher levels of maternal overprotection, as reported by the child, were associated with elevations in BI among children carrying two copies of the lower expressing 5-HTTLPR alleles (S or L_G), but not among those carrying only one copy or those homozygous for the L_A allele. In addition, this interaction was specific for the social component of BI, not the nonsocial component. This relation was maintained even after statistically controlling for children’s and mother’s psychopathology. Together, these findings add to emerging research demonstrating that G × E interactions predict variation in BI during childhood.     

View combination: a generalization mechanism for visual recognition

We examined whether view combination mechanisms shown to underlie object and scene recognition can integrate visual information across views that have little or no three-dimensional information at either the object or scene level. In three experiments, people learned four “views” of a two dimensional visual array derived from a three-dimensional scene. In Experiments 1 and 2, the stimuli were arrays of colored rectangles that preserved the relative sizes, distances, and angles among objects in the original scene, as well as the original occlusion relations. Participants recognized a novel central view more efficiently than any of the Trained views, which in turn were recognized more efficiently than equidistant novel views. Experiment 2 eliminated presentation frequency as an explanation for this effect. Experiment 3 used colored dots that preserved only identity and relative location information, which resulted in a weaker effect, though still one that was inconsistent with both part-based and normalization accounts of recognition. We argue that, for recognition processes to function so effectively with such minimalist stimuli, view combination must be a very general and fundamental mechanism, potentially enabling both visual recognition and categorization.     

Contrasting effects of feature-based statistics on the categorisation and basic-level identification of visual objects

Conceptual representations are at the heart of our mental lives, involved in every aspect of cognitive functioning. Despite their centrality, a long-standing debate persists as to how the meanings of concepts are represented and processed. Many accounts agree that the meanings of concrete concepts are represented by their individual features, but disagree about the importance of different feature-based variables: some views stress the importance of the information carried by distinctive features in conceptual processing, others the features which are shared over many concepts, and still others the extent to which features co-occur. We suggest that previously disparate theoretical positions and experimental findings can be unified by an account which claims that task demands determine how concepts are processed in addition to the effects of feature distinctiveness and co-occurrence. We tested these predictions in a basic-level naming task which relies on distinctive feature information (Experiment 1) and a domain decision task which relies on shared feature information (Experiment 2). Both used large-scale regression designs with the same visual objects, and mixed-effects models incorporating participant, session, stimulus-related and feature statistic variables to model the performance. We found that concepts with relatively more distinctive and more highly correlated distinctive relative to shared features facilitated basic-level naming latencies, while concepts with relatively more shared and more highly correlated shared relative to distinctive features speeded domain decisions. These findings demonstrate that the feature statistics of distinctiveness (shared vs. distinctive) and correlational strength, as well as the task demands, determine how concept meaning is processed in the conceptual system.     

Effort in the face of difference: Feeling like a non‐prototypical group member motivates effort

Three studies examined the relationship between individuals' perceived “prototypicality” in a group, their subsequent self‐presentation goals, and individual effort in that group. Consistent with the finding that feelings of marginal ingroup membership status elicit a desire to seek stronger social connections within ingroups, we predicted that non‐prototypical group members will have more salient self‐presentation goals than prototypical members, and as such will exert more individual effort to exhibit the value of their membership to the group. Correlational Study 1 confirmed that non‐prototypical group members may be more likely than prototypical members to volunteer for activities that would benefit their group. Two experimental studies were then conducted to test the causal influence of feelings of prototypicality while also identifying theoretically relevant moderating conditions of perceived task efficacy (Study 2) and public versus private task performance (Study 3). These findings suggest that effortful performance in groups is partly motivated by the desire to foster social ties. Copyright © 2012 John Wiley & Sons, Ltd.     

Value Commitment,Resolute Choice,and the Normative Foundations of Behavioural Welfare Economics

Given the endowment effect, the role of attention in decision-making, and the framing effect, most behavioural economists agree that it would be a mistake to accept the satisfaction of revealed preferences as the normative criterion of choice. Some have suggested that what makes agents better off is not the satisfaction of revealed preferences, but ‘true’ preferences, which may not always be observed through choice. While such preferences may appear to be an improvement over revealed preferences, some philosophers of economics have argued that they face insurmountable epistemological, normative, and methodological challenges. This article introduces a new kind of true preference – values-based preferences – that blunts these challenges. Agents express values-based preferences when they choose in a manner that is compatible with a consumption plan grounded in a value commitment that is normative, affective, and stable for the agent who has one. Agents who choose according to their plans are resolute choosers. My claim is that while values-based preferences do not apply to every choice situation, this kind of preference provides a rigorous way for thinking about classic choice situations that have long interested behavioural economists and philosophers of economics, such as ‘Joe-in-the-cafeteria.’