Investigating the modality specificity of response selection using a temporal flanker task

The neurocognitive architecture for response selection is uncertain. Some theorists suggest that it is mediated by an amodal central mechanism, whereas others propose a set of independent control mechanisms. In a functional neuroimaging experiment, we investigated the nature of response selection by examining how its underlying brain mechanisms are affected by stimulus modality. To do this, we used a modified flanker task, in which the target and flanker (distractor) stimuli differed in time rather than space, making it accessible for both visual and auditory stimuli. As in the traditional flanker task, larger reaction times were observed for incongruent than congruent trials (i.e., a congruency effect) for both modalities. Congruency affected brain activation for both modalities in prefrontal cortex, parietal cortex, and the putamen. Modality-dependent activation was found in additional prefrontal and parietal regions for the visual modality and in left inferior prefrontal cortex for the auditory modality. Modality-dependent activity specifically related to response congruency was also found in sensory cortical regions. These data suggest that modality affects the brain regions throughout the cortex mediating response selection even for conceptually identical stimuli and tasks. They are consistent with the hypothesis that (at least partially) independent brain networks mediate response selection and that input modality may be a powerful factor for organizing neural activity to support task performance.     

Piéron's Law holds during stroop conflict: insights into the architecture of decision making

Piéron's Law describes the relationship between stimulus intensity and reaction time. Previously (Stafford & Gurney, 2004), we have shown that Piéron's Law is a necessary consequence of rise-to-threshold decision making and thus will arise from optimal simple decision-making algorithms (e.g., Bogacz, Brown, Moehlis, Holmes, & Cohen, 2006). Here, we manipulate the color saturation of a Stroop stimulus. Our results show that Piéron's Law holds for color intensity and color-naming reaction time, extending the domain of this law, in line with our suggestion of the generality of the processes that can give rise to Piéron's Law. In addition, we find that Stroop condition does not interact with the effect of color saturation; Stroop interference and facilitation remain constant at all levels of color saturation. An analysis demonstrates that this result cannot be accounted for by single-stage decision-making algorithms which combine all the evidence pertaining to a decision into a common metric. This shows that human decision making is not information-optimal and suggests that the generalization of current models of simple perceptual decision making to more complex decisions is not straightforward.     

Validity of Resumé Reviewers' Inferences Concerning Applicant Personality Based on Resumé Evaluation

Recruiters infer personal traits from job applicants' resumés and use these inferences in evaluating job applicants' employability. No research to date, however, has determined if resumé reviewers' inferences of applicants' personality drawn solely from resumé biographical data are valid. In the present study, resumé reviewers (N=52) examined one of two applicant resumés and then described the applicant's personality based on the Big 5 taxonomy. Validities of reviewers' inferences concerning applicant personality were assessed by correlating resumé reviewers' judgments with applicants' self‐reported Big 5 personality scores. Results suggested that valid personality inferences are possible based solely on resumé evaluation. We also found evidence suggesting that attending a brief training session may enhance reviewers' accuracy when inferring applicants' personality from resumé information.     

Further validation of the MMPI-2 and MMPI-2-RF Response Bias Scale: findings from disability and criminal forensic settings

The present study extends the validation of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) Response Bias Scale (RBS; R. O. Gervais, Y. S. Ben-Porath, D. B. Wygant, & P. Green, 2007) in separate forensic samples composed of disability claimants and criminal defendants. Using cognitive symptom validity tests as response bias indicators, the RBS exhibited large effect sizes (Cohen's ds = 1.24 and 1.48) in detecting cognitive response bias in the disability and criminal forensic samples, respectively. The scale also added incremental prediction to the traditional MMPI-2 and the MMPI-2-RF overreporting validity scales in the disability sample and exhibited excellent specificity with acceptable sensitivity at cutoffs ranging from 90T to 120T. The results of this study indicate that the RBS can add uniquely to the existing MMPI-2 and MMPI-2-RF validity scales in detecting symptom exaggeration associated with cognitive response bias.     

Learning achievement, social adjustment, and family conflict among Bedouin-Arab children from polygamous and monogamous families

A sample of 146 Bedouin-Arab pupils from polygamous and monogamous families participated in this study, which was conducted in a Bedouin-Arab village in the Negev, Israel. The authors compared learning achievement, social adjustment, and family conflict. Data revealed differences between the two groups: The children from monogamous families had higher levels of learning achievement than did the children from polygamous families; in addition, those from monogamous families adjusted to the school framework better than did those from polygamous families. The mean conflict rating of children from polygamous families was higher than that of their counterparts from monogamous families. The father's level of education tended to be inversely correlated with family size in terms of both number of children and number of wives.     

Chronic stress accelerates atherosclerosis in the apolipoprotein E deficient mouse

Conventional cardiovascular risk factors such as cholesterol and blood pressure do not account fully for variation in coronary heart disease suggesting the involvement of additional mechanisms. We have examined the effects of a chronic psychological stress protocol on the development of atherosclerosis in the apolipoprotein E knockout mouse. We observed a 3-fold increase in staining for atheroma accompanied by a 10-fold increase in corticosterone concentrations in mice stressed for 12 weeks. These data suggest that chronic mild stress can induce or accelerate the development of atherosclerosis.