Relationship between reaction time variability and motor skill development in ADHD

Slower and more variable reaction times to computerized tasks have been documented in children diagnosed with attention deficit/hyperactivity disorder (ADHD). Recent research supports a role for attentional lapses in generating abnormally variable and slow responses. However, given the association between ADHD and impairments in motor control, we hypothesized that slower or more variable reaction times might also correlate with motor development. The aim of this case-control study was to explore the relationship between motor function, reaction speed and variability, and ADHD. After comprehensive educational and clinical assessments, motor skill development was evaluated in 35 children ages 9 to 14 (19 with ADHD) using the Physical and Neurological Examination for Subtle Signs (PANESS) test battery. Finger-sequencing speed and variability were quantified with goniometers. Reaction times were measured with 20 trials each of computerized simple and choice (binary) tasks. Compared to healthy controls, children with ADHD had slower and more variable reaction times, and these findings correlated with impaired motor development (PANESS) and slow and variable finger sequencing (goniometers). Further studies of motor development in ADHD may identify factors influencing speed and variability of reaction times.     

Differential effects of visual-spatial attention on response latency and temporal-order judgment

Summary Theorists from both classical structuralism and modern attention research have claimed that attention to a sensory stimulus enhances processing speed. However, they have used different operations to measure this effect, viz., temporal-order judgment (TOJ) and reaction-time (RT) measurement. We report two experiments that compared the effect of a spatial cue on RT and TOJ. Experiment 1 demonstrated that a nonmasked, peripheral cue (the brief brightening of a box) affected both RT and TOJ. However, the former effect was significantly larger than the latter. A masked cue had a smaller, but reliable, effect on TOJ. In Experiment 2, the effects of a masked cue on RT and TOJ were compared under identical stimulus conditions. While the cue had a strong effect on RT, it left TOJ unaffected. These results suggest that a spatial cue may have dissociable effects on response processes and the processes that lead to a conscious percept. Implications for the concept of direct parameter specification and for theories of visual attention are discussed.     

Relationship between reaction time variability and motor skill development in ADHD

Slower and more variable reaction times to computerized tasks have been documented in children diagnosed with attention deficit/hyperactivity disorder (ADHD). Recent research supports a role for attentional lapses in generating abnormally variable and slow responses. However, given the association between ADHD and impairments in motor control, we hypothesized that slower or more variable reaction times might also correlate with motor development. The aim of this case-control study was to explore the relationship between motor function, reaction speed and variability, and ADHD. After comprehensive educational and clinical assessments, motor skill development was evaluated in 35 children ages 9 to 14 (19 with ADHD) using the Physical and Neurological Examination for Subtle Signs (PANESS) test battery. Finger-sequencing speed and variability were quantified with goniometers. Reaction times were measured with 20 trials each of computerized simple and choice (binary) tasks. Compared to healthy controls, children with ADHD had slower and more variable reaction times, and these findings correlated with impaired motor development (PANESS) and slow and variable finger sequencing (goniometers). Further studies of motor development in ADHD may identify factors influencing speed and variability of reaction times.     

Book Reviews

Book Reviewed
The Politics of Cultural Differences. By David C. Leege, Kenneth D. Wald, Brian S. Krueger, and Paul D. Mueller. Princeton, NJ: Princeton University Press. 2002. 304 pp. $21.95 paper, $60 cloth.
The Psychological Assessment of Political Leaders. Edited by Jerrold M. Post, M.D. Ann Arbor, MI: University of Michigan Press. 2003. 412 pp.
FDR's Body Politics: The Rhetoric of Disability. By Davis W. Houck and Amos Kiewe. College Station, TX: Texas A&M University Press. 2003. 141 + xii pp.
The Power of Legitimacy: Assessing the Role of Norms in Crisis Bargaining. By Christopher Gelpi. Princeton, NJ: Princeton University Press. 2003. 232 pp. $39.50.     

Reaping the benefits of task conflict in teams: the critical role of team psychological safety climate

Past research suggests that task conflict may improve team performance under certain conditions; however, we know little about these specific conditions. On the basis of prior theory and research on conflict in teams, we argue that a climate of psychological safety is one specific context under which task conflict will improve team performance. Using evidence from 117 project teams, the present research found that psychological safety climate moderates the relationship between task conflict and performance. Specifically, task conflict and team performance were positively associated under conditions of high psychological safety. The results support the conclusion that psychological safety facilitates the performance benefits of task conflict in teams. Theoretical implications and suggestions for future research are discussed.     

Are daily fluctuations in perceived environment associated with walking?

The physical environment is thought to influence walking; however, daily variations in perceived environment have received little attention. The current study sought to examine if key within-person factors (i.e., implementation intentions, social support, affect and self-efficacy) would be associated with walking and if perceived access to supportive environments (e.g., access to nice walking paths) and perceived environmental barriers (e.g., bad weather and safety issues) were uniquely associated with walking after controlling for other constructs. Participants (N = 14, 50.0% men, 78.6% White, M age = 59.4 ± 6.4) were in the intervention arm of an 8-week controlled trial promoting walking via personal digital assistants. Participants completed electronic surveys twice a day (total entries = 804) in which they reported brisk walking levels and psychosocial and environmental factors. Multilevel modelling was used to examine within-person variations in constructs as determinants of walking. Results suggested that daily variations in implementation intentions, social support and positive affect were positively associated with walking. Further, perceived access to supportive environments, though not perceived environmental barriers, was positively associated with walking after controlling for other constructs (p < 0.05). Future research should explore intervention components that target context-specific information about perceived access to supportive environments as part of a broader perspective on intervention development.     

Effects of photoaging information and UV photo on sun protection intentions and behaviours: A cross-regional comparison

The physical environment is thought to influence walking; however, daily variations in perceived environment have received little attention. The current study sought to examine if key within-person factors (i.e., implementation intentions, social support, affect and self-efficacy) would be associated with walking and if perceived access to supportive environments (e.g., access to nice walking paths) and perceived environmental barriers (e.g., bad weather and safety issues) were uniquely associated with walking after controlling for other constructs. Participants (N?=?14, 50.0% men, 78.6% White, M age?=?59.4?±?6.4) were in the intervention arm of an 8-week controlled trial promoting walking via personal digital assistants. Participants completed electronic surveys twice a day (total entries?=?804) in which they reported brisk walking levels and psychosocial and environmental factors. Multilevel modelling was used to examine within-person variations in constructs as determinants of walking. Results suggested that daily variations in implementation intentions, social support and positive affect were positively associated with walking. Further, perceived access to supportive environments, though not perceived environmental barriers, was positively associated with walking after controlling for other constructs (p?<?0.05). Future research should explore intervention components that target context-specific information about perceived access to supportive environments as part of a broader perspective on intervention development.     

On the nature of quantum mechanics

Summary It is argued that the EPR paradox cannot be resolved in the context of quantum mechanics. Bell's theorem is shown to be equivalent to a Belinfante theory of zero type. It is concluded therefore that it cannot have as wide a range of applicability in excluding Hidden Variable Theories as commonly alleged. It follows that standard quantum mechanics should not be regarded as a complete theory in Einstein's sense. Indeed, it is argued that a purely probabilistic theory cannot be the basis of a comprehensive understanding of physics. An attempt is made to formulate a deterministic, local Hidden Variable Theory to account for the Bohm-Einstein thought experiment reproducing quantum mechanical predictions.     

Effects of Prenatal and Postbirth Intimate Partner Violence on Preschool-Age Children’s Dissociative Symptoms

Studies on the effects of intimate partner violence (IPV) on children have typically focused on IPV to which children were exposed after their birth. However, research has also demonstrated the effect of prenatal IPV on children’s psychological functioning, although this has not yet been studied with respect to dissociation. In this study, we examined the association between prenatal and postbirth IPV and dissociative symptoms among preschool-age children using a Bayesian approach to multiple regression. Results indicated that prenatal IPV predicts child dissociative symptoms over and above postbirth IPV and other negative life events that the child has experienced. These results provide further evidence for the role prenatal IPV plays in the development of child psychopathology and suggest directions for future research and intervention.