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.     

Behavioral Approach System Sensitivity and Risk Taking Interact to Predict Left-Frontal EEG Asymmetry

The Behavioral Approach System (BAS) hypersensitivity theory of bipolar disorder (BD; Alloy & Abramson, 2010; Depue & Iacono, 1989) suggests that hyperreactivity in the BAS results in the extreme fluctuations of mood characteristic of BD. In addition to risk conferred by BAS hypersensitivity, cognitive and personality variables may play a role in determining risk. We evaluated relationships among BAS sensitivity, risk taking, and an electrophysiological correlate of approach motivation, relative left-frontal electroencephalography (EEG) asymmetry. BAS sensitivity moderated the relationship between risk taking and EEG asymmetry. More specifically, individuals who were high in BAS sensitivity showed left-frontal EEG asymmetry regardless of their level of risk-taking behavior. However, among individuals who were moderate in BAS sensitivity, risk taking was positively associated with asymmetry. These findings suggest that cognitive and personality correlates of bipolar risk may evidence unique contributions to a neural measure of trait-approach motivation. Clinical implications of these findings are discussed.     

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.     

Can negative attitudes toward patients with borderline personality disorder be changed? The effect of attending a STEPPS workshop

We sought to determine whether negative attitudes toward patients with borderline personality disorder (BPD) can be modified through education. Mental health clinicians attended a 1-day workshop on the Systems Training for Emotional Predictability and Problem Solving (STEPPS) group treatment program for BPD. A questionnaire to assess attitudes towards BPD was given to 271 clinicians before and after the workshop. Following the workshop, clinicians endorsed having significantly greater empathy toward patients with BPD, and having greater awareness of the distress and low self-esteem associated with the disorder. Significant improvement was seen in the clinicians' attitudes toward patients with BPD and their desire to work with them. Clinicians were significantly less likely to express dislike for BPD patients. They also reported feeling more competent in their ability to treat these patients. The study offers preliminary evidence that negative attitudes toward patients with BPD can be modified through education.     

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.     

Positive overgeneralization and Behavioral Approach System (BAS) sensitivity interact to predict prospective increases in hypomanic symptoms: a behavioral high-risk design

Recent work has identified Behavioral Approach System (BAS) sensitivity as a risk factor for the first onset and recurrence of mood episodes in bipolar disorder, but little work has evaluated risk factors for the prospective development of hypomanic symptoms in individuals at risk for, but without a history of, bipolar disorder. The present study used a prospective behavioral high-risk design to evaluate the impact of positive overgeneralization, a cognitive correlate of risk for hypomania, on hypomanic symptoms in individuals with high vs. moderate BAS sensitivity, but without a history of mood elevation. Hierarchical linear regressions indicated that upward positive overgeneralization and BAS sensitivity interacted to predict increased levels of hypomanic symptoms at follow-up, controlling for initial hypomanic symptoms. The pattern of this interaction was such that positive overgeneralization predicted higher levels of hypomanic symptoms among high-BAS, but not moderate-BAS, individuals. Thus, the self-reported tendency to experience grandiose increases in confidence following success may confer additional risk for mood elevation among individuals already at risk for developing bipolar disorder. Potential implications for prevention and treatment are discussed.