Individual differences in working memory capacity and dual-process theories of the mind

Dual-process theories of the mind are ubiquitous in psychology. A central principle of these theories is that behavior is determined by the interplay of automatic and controlled processing. In this article, the authors examine individual differences in the capacity to control attention as a major contributor to differences in working memory capacity (WMC). The authors discuss the enormous implications of this individual difference for a host of dual-process theories in social, personality, cognitive, and clinical psychology. In addition, the authors propose several new areas of investigation that derive directly from applying the concept of WMC to dual-process theories of the mind.     

Paradoxes in Double Extension Set Theories

Three systems of double extension set theory have been proposed by Andrzej Kisielewicz in two papers. In this paper, it is shown that the two stronger systems are inconsistent, and that the third, weakest system does not admit extensionality for general sets or the use of general sets as parameters in its comprehension scheme. The parameter-free version of the comprehension principle of double extension set theory is also shown to be inconsistent with extensionality. The definitions of the systems and a self-contained exposition of their properties is given, sufficient to develop the inconsistency proofs.     

Risk of false positives when identifying malingered profiles using the trauma symptom inventory

The Trauma Symptom Inventory (TSI; Briere, 1995) is a 100-item self-report measure of posttraumatic symptomatology that includes an Atypical Response (ATR) validity scale designed to differentiate honest from malingered profiles. In this study, using an analogue design to experimentally manipulate honest and malingered responses on the TSI, we found that proposed ATR cut scores produce a significant risk of false positives. Furthermore, the functioning of proposed cut scores worsened when we used posttraumatic stress disorder relevant samples and low estimates of malingering base rates. In light of these findings, the TSI should be used with caution when assessing claims of posttraumatic stress in forensic or disability settings.     

Involvement of 5-HT1A receptors in animal tests of anxiety and depression: evidence from genetic models

Clinical studies have suggested the involvement of 5-HT1A receptors in anxiety and depressive disorders because partial 5-HT1A receptor agonists such as buspirone are therapeutic. The present review considers evidence from genetic animal models that support a role for 5-HT1A receptors in anxiety-like and depressed-like behavior in animals. Selective breeding for differential hypothermic responses to a selective 5-HT1A receptor agonist led to the development of the high DPAT sensitive (HDS) and low DPAT sensitive (LDS) lines of rats. The HDS rats differ from the LDS rats on several behavioral measures reflective of anxiety or depression, including reduced social interaction, reduced responding in a conflict task and exaggerated immobility in the forced swim test. However, they do not differ from the LDS rats in the elevated plus maze task, which is a commonly used test of anxiety. Nor do the HDS rats exhibit a typical anxiogenic response to the hippocampal administration of the 5-HT1A agonist. Although the HDS rats do exhibit elevations in 5-HT1A receptors in regions of the limbic cortex, it is not clear whether these increases account for the behavioral differences. Paradoxically, 5-HT1A receptor knockout mice also exhibit anxiety-like behavior in the plus maze, open field and conflict tests compared to wild type mice. However, the knockouts exhibited less immobility in the forced swim test than wild type control mice. Recent studies using selective regional reinstatement of the receptor have implicated the postsynaptic 5-HT1A receptors in these changes in anxiety-like behavior. Thus, preliminary evidence from two different types of genetic animal models suggests that anxiety-like behavior can arise if the 5-HT1A receptor function is eliminated or overexpressed. Further study with additional tests of anxiety are needed to confirm this intriguing relationship.     

Do conjunction errors in auditory recognition imply feature migration?

It has recently been proposed that the feature values (e.g., pitch, duration, etc.) of tones are processed in separate perceptual channels and are later reintegrated to form the experience of a unitary percept. Patterns of errors in recognizing combinations of auditory features have been taken as failures of, and thus evidence for, an auditory feature-integration process. We outline an alternative interpretation of these effects based on similarity structure of the stimuli.     

Evaluating Single-Subject Treatment Research: Lessons Learned from the Aphasia Literature

The mandate for evidence-based practice has prompted careful consideration of the weight of the scientific evidence regarding the therapeutic value of various clinical treatments. In the field of aphasia, a large number of single-subject research studies have been conducted, providing clinical outcome data that are potentially useful for clinicians and researchers; however, it has been difficult to discern the relative potency of these treatments in a standardized manner. In this paper we describe an approach to quantify treatment outcomes for single-subject research studies using effect sizes. These values provide a means to compare treatment outcomes within and between individuals, as well as to compare the relative strength of various treatments. Effect sizes also can be aggregated in order to conduct meta-analyses of specific treatment approaches. Consideration is given to optimizing research designs and providing adequate data so that the value of treatment research is maximized.     

Spatial and nonspatial escape strategies in the Barnes maze

The Barnes maze is a spatial memory task that requires subjects to learn the position of a hole that can be used to escape the brightly lit, open surface of the maze. Two experiments assessed the relative importance of spatial (extra-maze) versus proximal visible cues in solving the maze. In Experiment 1, four groups of mice were trained either with or without a discrete visible cue marking the location of the escape hole, which was either in a fixed or variable location across trials. In Experiment 2, all mice were trained with the discrete visible cue marking the target hole location. Two groups were identical to the cued-target groups from Experiment 1, with either fixed or variable escape locations. For these mice, the discrete cue either was the sole predictor of the target location or was perfectly confounded with the spatial extra-maze cues. The third group also used a cued variable target, but a curtain was drawn around the maze to prevent the use of spatial cues to guide navigation. Probe trials with all escape holes blocked were conducted to dissociate the use of spatial and discrete proximal cues. We conclude that the Barnes maze can be solved efficiently using spatial, visual cue, or serial-search strategies. However, mice showed a strong preference for using the distal room cues, even when a discrete visible cue clearly marked the escape location. Importantly, these data show that the cued-target control version of the Barnes maze as typically conducted does not dissociate spatial from nonspatial abilities.     

Convergent and discriminant validity of psychopathy factors assessed via self-report: a comparison of three instruments

Psychopathy has been conceptualized as a personality disorder with distinctive interpersonal-affective and behavioral deviance features. The authors examine correlates of the factors of the Psychopathic Personality Inventory (PPI), Self-Report Psychopathy-II (SRP-II) scale, and Antisocial Process Screening Device (APSD) to understand similarities and differences among the constructs embodied in these instruments. PPI Fearless Dominance and SRP-II Factor 1 were negatively related to most personality disorder symptoms and were both predicted by high Dominance and low Neuroticism. In addition, PPI Fearless Dominance correlated positively with antisocial personality features, although SRP-II Factor 1 did not. In contrast, PPI Impulsive Antisociality, SRP-II Factor 2, and both APSD factors correlated with antisocial personality features and symptoms of nearly all personality disorders, and were predicted by low Love. Results suggest ways in which the measurement of the constructs in each instrument may be improved.     

Assessment of accurate self-knowledge

Despite ongoing theoretical interest in the accuracy of self-knowledge and its implications for mental health, few researchers have yet to tackle this topic directly. This may be due, in part, to several factors that make assessing individual differences in accurate self-knowledge especially difficult. In this article, we present a method for the assessment of accurate self-knowledge that relies on information gathered from the self, knowledgeable others, and observations of behavior in the laboratory, and we provide psychometric support for this newly developed assessment procedure. Specifically, we present evidence for internal consistency reliability, convergent and discriminant validity, and criterion-related validity. Other researchers interested in studying the accuracy of self-knowledge might wish to adopt this procedure in their own research endeavors.     

The driving anger expression inventory: a measure of how people express their anger on the road

Four ways people express their anger when driving were identified. Verbal Aggressive Expression (alpha=0.88) assesses verbally aggressive expression of anger (e.g., yelling or cursing at another driver); Personal Physical Aggressive Expression (alpha=0.81), the ways the person uses him/herself to express anger (e.g., trying to get out and tell off or have a physical fight with another driver); Use of the Vehicle to Express Anger (alpha=0.86), the ways the person uses his/her vehicle to express anger (e.g., flashing lights at or cutting another driver off in anger); and Adaptive/Constructive Expression (alpha=0.90), the ways the person copes positively with anger (e.g., focuses on safe driving or tries to relax). Aggressive forms can be summed into Total Aggressive Expression Index (alpha=0.90). Aggressive forms of expression correlated positively with each other (rs=0.39-0.48), but were uncorrelated or correlated negatively with adaptive/constructive expression (rs=-0.02 to -0.22). Aggressive forms of anger expression correlated positively with driving-related anger, aggression, and risky behavior; adaptive/constructive expression tended to correlate negatively with these variables. Differences in the strengths of correlations and regression analyses supported discriminant and incremental validity and suggested forms of anger expression contributed differentially to understanding driving-related behaviors. Theoretical and treatment implications were explored.