Are Motor Inhibition and Cognitive Flexibility Dead Ends in ADHD?

Executive dysfunction has been postulated as the core deficit in ADHD, although many deficits in lower order cognitive processes have also been identified. By obtaining an appropriate baseline of lower order cognitive functioning light may be shed on as to whether executive deficits result from problems in lower order and/or higher order cognitive processes. We examined motor inhibition and cognitive flexibility in relation to a baseline measure in 816 children from ADHD and control families. Multiple children in a family were tested in order to examine the familiality of the measures. No evidence was found for deficits in motor inhibition or cognitive flexibility in children with ADHD or their nonaffected siblings: Compared to their baseline speed and accuracy of responding, children with ADHD and their (non)affected siblings were not disproportionally slower or inaccurate when demands for motor inhibition or cognitive flexibility were added to the task. However, children with ADHD and their (non)affected siblings were overall less accurate than controls, which could not be attributed to differences in response speed. This suggests that inaccuracy of responding is characteristic of children having (a familial risk for) ADHD. Motor inhibition and cognitive flexibility as operationalized with mean reaction time were found to be familial. It is concluded that poorer performance on executive tasks in children with ADHD and their (non)affected siblings may result from deficiencies in lower order cognitive processes and not (only) from higher order cognitive processes/executive functions.     

The association between life events and suicide intent in self-poisoners with and without a history of deliberate self-harm: a preliminary study

The associations between life events in the 12 months preceding an episode of self-poisoning resulting in hospital attendance (the index episode), and the suicide intent of this episode were compared in individuals for whom the index episode was their first, episode and in individuals in whom it was a recurrence of DSH. Results indicated a significant interaction between independent life events, repetition status, and gender in the prediction of suicide intent, the association between life events and intent being moderated by repetition status in women only. The results provide preliminary evidence to suggest the presence of a suicidal process in women, in which the impact of negative life events on suicide intent diminishes across episodes.     

Patients suffering from nonspecific work-related upper extremity disorders exhibit insufficient movement strategies

The purpose of this research was to investigate whether patients experiencing nonspecific complaints of the forearm caused by sustained use of the personal computer exhibit deviant movement strategies as compared to healthy participants. Patients (N=10) and controls (N=24) performed a graphical aiming task combined with an auditory memory task. Force production (pen pressure), kinematic- and performance variables were recorded. During a trial, the control group gradually increased pen pressure from the stationary phases to the dynamic phase. The patients increased their pen pressure much more abruptly and to such a degree that the final pressure during real-time movement far exceeded that of the controls. Memory load led to a greater increase of pen pressure from the stationary phase to the dynamic phase in the patient group. Patients further displayed longer reaction times. The results are discussed within the framework of our recent theory on the role of neuromotor noise in the regulation of task performance under conditions of stress.     

Trends in Hanging and Firearm Suicide Rates in Australia: Substitution of Method?

This study examined the increase in the rate of suicide by hanging and an apparently simultaneous decrease in the rate of suicide by firearm as hypothetical evidence that Australian males have substituted one method of suicide for another. Trends in hanging and firearm suicide rates were examined from 1975 to 1998 for all Australian males and from 1971 to 1998 for a subset of Australian male youth, as well as a group of Australian males aged over 64 years at the time of their death. When the firearm suicide rate for Australian males declined the hanging rate increased simultaneously, with no statistical difference in the rate of change of the two methods. A similar pattern of simultaneous divergence in hanging and firearm suicide rates of a 15- to 24-year-old subgroup occurred at a not dissimilar rate over a longer time period. Rates of suicide by hanging were found to have begun increasing prior to the decline in firearm suicide. The declining rate of firearm suicide in the 15- to 24-year-old subgroup coincided with an increase in the overall suicide rate. Relationships between trends in hanging and firearm suicide differed between states and between urban and non-urban areas within Queensland, with the firearm suicide rate falling more rapidly in urban areas, especially following the introductions of restrictions to weapon purchases. Individual suicide method choice may be related to independent changes in the social acceptability of each method, as well as to an increasing prevalence of suicide in younger males, who are more likely to use the hanging method. The functioning and effect of social acceptability remains unclear, however. Intervention and prevention strategies should focus on challenging the social acceptability of hanging, especially among males aged 15 to 24 years.     

Visceral drives in retrospect: explanations about the inaccessible past

The present research demonstrates that the extent to which people appreciate the influence past visceral states have had on behavior (e.g., the influence hunger has had on food choice) depends largely on their current visceral state. Specifically, we found that when people were in a hot state (e.g., fatigued), they attributed behavior primarily to visceral influences, whereas when people were in a cold state (e.g., nonfatigued), they underestimated the influence of visceral drives and instead attributed behavior primarily to other, nonvisceral factors. This hot-cold empathy gap was observed when people made attributions about the past behavior of another person or themselves, and proved difficult to overcome, as participants could not correct for the biasing influence of their current visceral state when instructed to do so. These different attribution patterns also had consequences for people's satisfaction with their performance. Those who attributed their poor performance to visceral factors were more satisfied than those who made dispositional attributions.     

Some Results on Modal Axiomatization and Definability for Topological Spaces

We consider two topological interpretations of the modal diamond—as the closure operator (C-semantics) and as the derived set operator (d-semantics). We call the logics arising from these interpretations C-logics and d-logics, respectively. We axiomatize a number of subclasses of the class of nodec spaces with respect to both semantics, and characterize exactly which of these classes are modally definable. It is demonstrated that the d-semantics is more expressive than the C-semantics. In particular, we show that the d-logics of the six classes of spaces considered in the paper are pairwise distinct, while the C-logics of some of them coincide. Mathematics Subject Classifications (2000): 03B45, 54G99. Presented by Michael Zakharyaschev     

Why people engage in parasuicide: a cross-cultural study of intentions

Information obtained at interview from 1,646 parasuicide patients in 14 regions in 13 European countries participating in the WHO/EURO Multicentre Study on Suicidal Behaviour was used to study self-reported intentions involved in parasuicide. Comparisons were made across cultures, genders, and age groups. Although some statistically significant differences were found, the effect sizes were very small. The main finding from this study is thus that parasuicide patients in different countries tend to indicate that similar types of intentions are involved in their acts of parasuicide, and that the intentions do not vary greatly with gender or age. The hypothesis that rates of suicide and parasuicide vary between regions with the frequency with which suicidal intention is indicated by the patients was also tested, but was supported only for women and in relation to national suicide rates. The findings from this study are likely to be generalizable to other settings and have implications for clinical practice.