Localized disruption of Narp in medial prefrontal cortex blocks reinforcer devaluation performance

Neuronal activity regulated pentraxin (Narp) is a secreted protein that regulates α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors (AMPAR) aggregation and synaptogenesis. Mapping of Narp-positive neurons in brain has revealed it is prominently expressed in several limbic system projection pathways. Consistent with this localization pattern, Narp knockout mice show deficits in using the current value of a reinforcer to guide behavior, a critical function of the limbic system. To help assess whether this behavioral deficit is due to impairment of synaptogenesis during development or in modulating synaptic signaling in the mature brain, we have used a dominant negative Narp viral construct which blocks trafficking of endogenous Narp to axons. Focal injection of this viral construct into the medial prefrontal cortex (mPFC) of adult mice, a region containing Narp-positive projection neurons, blocked reinforcer devaluation. Thus, these results indicate that Narp released from mPFC neurons plays a key role in mediating synaptic changes underlying instrumental reinforcer devaluation.     

Objects do not aid inhibition of return in crossing the vertical meridian

Location-based cuing experiments have shown that inhibition of return (IOR) spreads beyond a cued location but appears to be confined to the cued hemifield by the vertical meridian. Previous studies have also shown that IOR can spread across objects and here we investigate whether an object can be used to mediate the spreading of IOR into the opposite hemifield. Two experiments used a rectangular object that surrounded four target locations, two to the left and right of a central fixation point. The spreading of IOR in the presence of the object was determined and compared with a condition where the object-frame was absent. Object-present and object-absent trials were either mixed within a block (Experiment 1) or divided into separate blocks (Experiment 2). Both experiments revealed robust inhibition in the cued but not the uncued hemifield, further demonstrating the hemifield-based spreading of IOR.     

Terror Management Theory: Implications for Understanding Prejudice,Stereotyping, Intergroup Conflict,and Political Attitudes

Terror management theory posits that to maintain psychological security despite the awareness of personal mortality, humans must maintain faith in cultural worldviews. These worldviews provide ways for humans to believe they are significant enduring beings in a world of meaning rather than mere animals fated only to obliteration upon death. We review basic support for terror management theory and research exploring the implications of terror management theory for understanding prejudice, stereotyping, intergroup conflict, and political attitudes. This research shows that when the psychological need to defend these worldviews is heightened by reminders of death (mortality salience), prejudice, stereotyping, and support for charismatic leaders and aggression against outgroups is increased. Terror management concerns also lead targets of prejudice to disidentify with their ingroup and confirm negative stereotypes of their group. We conclude by considering the implications of terror management theory and research for the alleviation of prejudice and intergroup conflict.     

Your divided attention, please! The maintenance of multiple attentional control sets over distinct regions in space

When non-informative peripheral cues precede a target defined by a specific feature, cues that share the critical feature will capture attention while cues that do not will be effectively ignored. We tested whether different attentional control sets can be simultaneously maintained over distinct regions of space. Participants were instructed to respond only to specific colored targets at specific locations. Most trials included non-predictive cues whose location and/or color were either congruent or incongruent with the spatial and/or color properties of the impending target. We observed contingent capture only for cues that were consistent with the attentional control set applied to that region of space. This is the first demonstration that separate attentional control sets can be simultaneously maintained at distinct spatial locations, with implications for the flexibility of endogenous control over automatic attentional orienting.     

The path or the goal? Decision vs. information focus in biased information seeking after preliminary decisions

Research on the phenomenon of selective exposure to information demonstrates that after preliminary or final decisions, people show a preference for supporting rather than conflicting information (confirmation bias). In this article, we examine conditions that increase or decrease distortions in the search for information. We report on four experiments indicating that the confirmation bias is influenced by whether people focus on their decision or on the presented pieces of information during the information search. Focusing on the decision, for example, because a reward for a correct decision is promised or simply because participants repeatedly think of it, increases the confirmation bias. On the other hand, if participants focus on the available pieces of information because they have to invest money in order to search for information or because they have to evaluate the individual pieces of information, the confirmation bias decreases. Implications for theoretical understanding and interventions for decision-making situations are discussed.     

Measuring model flexibility with parameter space partitioning: an introduction and application example

A primary criterion on which models of cognition are evaluated is their ability to fit empirical data. To understand the reason why a model yields a good or poor fit, it is necessary to determine the data-fitting potential (i.e., flexibility) of the model. In the first part of this article, methods for comparing models and studying their flexibility are reviewed, with a focus on parameter space partitioning (PSP), a general-purpose method for analyzing and comparing all classes of cognitive models. PSP is then demonstrated in the second part of the article in which two connectionist models of speech perception (TRACE and ARTphone) are compared to learn how design differences affect model flexibility.     

Genetic Testing of Children at Risk for Adult Onset Conditions: When is Testing Indicated?

We report a family with an extensive history of colon cancer consistent with hereditary nonpolyposis colorectal cancer (HNPCC). A specific disease causing mutation was identified in affected individuals; p.W714X MLH1 mutation. Given the very young age of onset of cancer in some affected family members, with the youngest affected individual being 19 years of age, genetic counseling was recommended to children as young as 9 years. Ethical issues arose when affected families requested genetic testing for their underage children. Here we describe and debate the value of offering molecular testing for this adult onset disorder to several children in this particular family. We also examine possible molecular causes for the very young age of onset in some family members.     

Cognitive processes in dissociation: an analysis of core theoretical assumptions

Dissociation is typically defined as the lack of normal integration of thoughts, feelings, and experiences into consciousness and memory. The present article critically evaluates the research literature on cognitive processes in dissociation. The authors' review indicates that dissociation is characterized by subtle deficits in neuropsychological performance (e.g., heightened distractibility). Some of the cognitive phenomena (e.g., weakened cognitive inhibition) associated with dissociation appear to be dependent on the emotional or attentional context. Contrary to a widespread assumption in the clinical literature, dissociation does not appear to be related to avoidant information processing. Rather, it is associated with an enhanced propensity toward pseudo-memories, possibly mediated by heightened levels of interrogative suggestibility, fantasy proneness, and cognitive failures. Evidence for a link between dissociation and either memory fragmentation or early trauma based on objective measures is conspicuously lacking. The authors identify a variety of methodological issues and discrepancies that make it difficult to articulate a comprehensive framework for cognitive mechanisms in dissociation. The authors conclude with a discussion of research domains (e.g., sleep-related experiences, drug-related dissociation) that promise to advance our understanding of cognition and dissociation.