Inhibition,Reinforcement Sensitivity and Temporal Information Processing in ADHD and ADHD+ODD: Evidence of a Separate Entity?

This study compared children with ADHD-only, ADHD+ODD and normal controls (age 8–12) on three key neurocognitive functions: response inhibition, reinforcement sensitivity, and temporal information processing. The goal was twofold: (a) to investigate neurocognitive impairments in children with ADHD-only and children with ADHD+ODD, and (b) to test whether ADHD+ODD is a more severe from of ADHD in terms of neurocognitive performance. In Experiment 1, inhibition abilities were measured using the Stop Task. In Experiment 2, reinforcement sensitivity and temporal information processing abilities were measured using a Timing Task with both a reward and penalty condition. Compared to controls, children with ADHD-only demonstrated impaired inhibitory control, showed more time underestimations, and showed performance deterioration in the face of reward and penalty. Children with ADHD+ODD performed in-between children with ADHD-only and controls in terms of inhibitory controls and the tendency to underestimate time, but were more impaired than controls and children with ADHD-only in terms of timing variability. In the face of reward and penalty children with ADHD+ODD improved their performance compared to a neutral condition, in contrast to children with ADHD-only. In the face of reward, the performance improvement in the ADHD+ODD group was disproportionally larger than that of controls. Taken together the findings suggest that, in terms of neurocognitive functioning, comorbid ADHD+ODD is a substantial different entity than ADHD-only.     

How Are Traits Related to Problem Behavior in Preschoolers? Similarities and Contrasts Between Temperament and Personality

The lack of empirical research relating temperament models and personality hinders conceptual integration and holds back research linking childhood traits to problem behavior or maladjustment. This study evaluates, within a sample of 443 preschoolers, the relationships between children’s maladaptation and traits measured by three temperament models (Thomas and Chess, Buss and Plomin, and Rothbart), and a Five-Factor based personality model. Adequate reliabilities and expected factor structures are demonstrated for most scales. A joint principal component analysis combining 28 temperament and 18 personality scales indicates a six-factor model, distinguishing Sociability, Activity, Conscientiousness, Disagreeableness, Emotionality, and Sensitivity. Regression analyses reveal that although single temperament and personality scales explain from 23% to 37% of problem behavior variance, the six components explain from 41% to 49% and provide a clearer differentiation among CBCL-problem scales. This age-specific taxonomy refines and corroborates conclusions based on narrative reviews and furnishes a more balanced view of trait–maladjustment relationships.

The time course effect of moderate intensity exercise on response execution and response inhibition

This research aimed to investigate the time course effect of a moderate steady-state exercise session on response execution and response inhibition using a stop-task paradigm. Ten participants performed a stop-signal task whilst cycling at a carefully controlled workload intensity (40% of maximal aerobic power), immediately following exercise and 30 min after exercise cessation. Results showed that moderate exercise enhances a subjects’ ability to execute responses under time pressure (shorter Go reaction time, RT without a change in accuracy) but also enhances a subjects’ ability to withhold ongoing motor responses (shorter stop-signal RT). The present outcomes reveal that the beneficial effect of exercise is neither limited to motor response tasks, nor to cognitive tasks performed during exercise. Beneficial effects of exercise remain present on both response execution and response inhibition performance for up to 52 min after exercise cessation.     

Domestic violence against women: Understanding social processes and women's experiences

The prevalence of domestic abuse against women has been estimated as high as one in four. The risk is particularly high for women who are younger, economically dependent, unemployed and with children. Research about the factors that maintain situations of abuse has generally focused separately on the coping strategies of women, barriers to leaving the relationship and the perpetrators' means of abuse. In this study we used a community psychology perspective to seek a broader understanding of what maintains situations of abuse, in order to suggest interventions in a rural County in the North of England. Twelve women who had experienced domestic abuse and had used voluntary sector services agreed to be interviewed about their experiences and the resources and strategies available to them. Using grounded theory we generated four themes: (1) Commonalities and contradictions in the experience of abuse; (2) living with abuse; (3) the response of systems reinforced or challenged the abuse and (4) dealing with abuse beyond the relationship. These findings illustrate how situations of domestic abuse can be prolonged by limited options available to victims for support and protection, and a lack of active public acknowledgement that domestic abuse is unacceptable. Copyright © 2009 John Wiley & Sons, Ltd.     

Sleep deprivation affects multiple distinct cognitive processes

Sleep deprivation adversely affects the ability to perform cognitive tasks, but theories range from predicting an overall decline in cognitive functioning (because of reduced stability in attentional networks) to claiming specific deficits in executive functions. In the present study, we measured the effects of sleep deprivation on a two-choice numerosity discrimination task. A diffusion model was used to decompose accuracy and response time distributions in order to produce estimates of distinct components of cognitive processing. The model assumes that, over time, noisy evidence from the task stimulus is accumulated to one of two decision criteria and that parameters governing this process can be extracted and interpreted in terms of distinct cognitive processes. The results showed that sleep deprivation affects multiple components of cognitive processing, ranging from stimulus processing to peripheral nondecision processes. Thus, sleep deprivation appears to have wide-ranging effects: Reduced attentional arousal and impaired central processing combine to produce an overall decline in cognitive functioning.     

TwoMP: A MATLAB graphical user interface for two-mode partitioning

Two-way two-mode data occur in almost every domain of scientific psychology. The information present in such data, however, may be hard to grasp because of the dimensions of one or both modes. Two-mode partitioning addresses this problem by breaking down both modes into a number of mutually exclusive and exhaustive subsets. Although such a technique may be very useful, up to now, software—and consequently, two-mode partitioning—has been available only to a handful of specialists in the field. In this article, we present a free, easy-to-use MATLAB graphical user interface (TwoMP) for two-mode partitioning models, specifically developed for nonspecialist users. A short formal introduction is given on the statistics of the method, and the basic use of TwoMP is demonstrated with an example.     

Regions of the MPFC differentially tuned to social and nonsocial affective evaluation

The medial prefrontal cortex (MPFC) reliably activates in social cognition and reward tasks. This study locates distinct areas for each. Participants made evaluative (positive/negative) or social (person/not a person) judgments of pictured positive or negative people and objects in a slow event-related design. Activity in an anterior rostral region (arMPFC) was significantly greater for positive than for negative persons but did not show a valence effect for objects, and this was true regardless of the judgment task. This suggests that the arMPFC is tuned to social valence. Interestingly, however, no regions of the MPFC were found to be responsive to social information independently of valence. A region-of-interest analysis of the paraanterior cingulate cortex (pACC), previously implicated in reward processing, demonstrated sensitivity to the valence of all stimuli, whether persons or objects, across tasks. Affective evaluation may be a general function of the MPFC, with some regions being tuned to more specific domains of information (e.g., social) than are others.