Uncovering mental representations with Markov chain Monte Carlo

A key challenge for cognitive psychology is the investigation of mental representations, such as object categories, subjective probabilities, choice utilities, and memory traces. In many cases, these representations can be expressed as a non-negative function defined over a set of objects. We present a behavioral method for estimating these functions. Our approach uses people as components of a Markov chain Monte Carlo (MCMC) algorithm, a sophisticated sampling method originally developed in statistical physics. Experiments 1 and 2 verified the MCMC method by training participants on various category structures and then recovering those structures. Experiment 3 demonstrated that the MCMC method can be used estimate the structures of the real-world animal shape categories of giraffes, horses, dogs, and cats. Experiment 4 combined the MCMC method with multidimensional scaling to demonstrate how different accounts of the structure of categories, such as prototype and exemplar models, can be tested, producing samples from the categories of apples, oranges, and grapes.     

Evaluation of stimulus control over a communication response as an intervention for stereotypical responding

Stereotypical behavior maintained by automatic reinforcement often does not result in harm but may be undesirable in some situations. In the current investigation, participants were 2 individuals who engaged in nonharmful stereotypical responses shown in an analogue functional analysis to be insensitive to social contingencies. After bringing these responses under stimulus control using differential punishment, both participants learned a mand to terminate punishment for stereotypy. We also assessed whether the mand could be brought under stimulus control.     

Rising to the threat: Reducing stereotype threat by reframing the threat as a challenge

In two experiments, we found that the performance-inhibiting consequences of stereotype threat were eliminated when the threat was subtly reframed as a challenge. In Experiment 1, Black school children in North Carolina completed a 10-item mathematics test. Participants who reported their race before taking the test performed more poorly than participants who reported their race after completing the test, unless the test was framed as a challenge. Experiment 2 replicated this effect with undergraduates at a prestigious university. When reminded that they graduated from high schools that were poorly represented at the university, they performed more poorly than their peers on a math test. However, when the test was reframed as a challenge, this threat had no effect on their performance. These findings are discussed in terms of their theoretical and practical applications for both educational and athletic training.     

Evidence that episodic memory impairment during tobacco abstinence is independent of attentional mechanisms

Previous studies have demonstrated reductions in episodic memory during nicotine withdrawal. However, these studies have been unable to dissociate memory reductions from losses in attention associated with tobacco abstinence. In the present study, the authors sought to determine whether episodic memory reduction is a primary effect of nicotine withdrawal during tobacco abstinence. Heavy smokers were tested when smoking normally and following 24 hrs of abstinence. Participants were tested with a recognition memory task in which items were studied under full and divided attention conditions. Forward digit span and backward digit span were also included as control measures. Withdrawal was associated with a reduction in memory performance that was independent of attention at encoding. The authors conclude that impairment of episodic memory is a primary effect of nicotine withdrawal during tobacco abstinence. Further research is required to determine if this is associated with continued use of tobacco and cessation failures.     

Trends in Publication of Spirituality/Religiosity Articles in Critical Care Populations

Research on spirituality and religion (S/R) is receiving more attention as healthcare staff recognize the importance of treating the whole person. This is especially pertinent in critical care, where patients and families deal with a multitude of issues. As not all research comes exclusively from theologically educated authors, this study explored publication trends of S/R articles in critical care. Findings indicated medically credentialed professionals, not chaplains and/or pastoral care staff, constituted the majority of authors in S/R articles.     

Reversed Resolution in Reducing General Satisfiability Problem

In the following we show that general property S considered by Cowen [1], Cowen and Kolany in [3] and earlier by Cowen in [2] and Kolany in [4] as hypergraph satisfiability, can be constructively reduced to (3, 2) · SAT, that is to satisfiability of (at most) triples with two-element forbidden sets. This is an analogue of the“classical” result on the reduction of SAT to 3 · SAT.     

A Psychometric Analysis of the Revised Child Anxiety and Depression Scale—Parent Version in a Clinical Sample

The Revised Child Anxiety and Depression Scale—Parent Version (RCADS-P) is a 47-item parent-report questionnaire of youth anxiety and depression, with scales corresponding to the DSM-IV categories of Separation Anxiety Disorder, Social Phobia, Generalized Anxiety Disorder (GAD), Panic Disorder, Obsessive-Compulsive Disorder, and Major Depressive Disorder (MDD). The RCADS-P is currently the only parent-report questionnaire that concurrently assesses youth symptomatology of individual anxiety disorders as well as depression in accordance with DSM-IV nosology. The present study examined the psychometric properties of the RCADS-P in a large (N = 490), clinic-referred sample of youths. The RCADS-P demonstrated favorable psychometric properties, including high internal consistency, convergent/divergent validity, as well as strong discriminant validity—evidencing an ability to discriminate between anxiety and depressive disorders, as well as between the targeted anxiety disorders. Support for the DSM-related six-factor RCADS-P structure was also evidenced. This structure demonstrated superior fit to a recently suggested alternative to the DSM-IV classification of anxiety and affective disorders—namely, the MDD/GAD “distress” factor.     

Composition and consistency of the desired affective state: The role of personality and motivation

Using longitudinal and experience sampling designs, the consistency and composition, and personality and motivational predictors, of the desired affective state are explored. Findings indicate that, while the desired affect is relatively malleable throughout one semester, it is relatively stable throughout 1 week. Personality and motivations/goals were related to the content of the desired affective state. Extraversion, neuroticism, agreeableness, and conscientiousness were related to the content of the desired affective state. In addition, higher-order goals predicted the content of the desired affective state. Our results suggest that the content of the desired affective state may be largely dependent on personality, motivation, and, potentially, an interaction between personality and motivation.