Association between aerobic fitness and visuospatial performance in healthy older adults.

This study examined whether chronic physical exercise activity is associated with better neurocognitive performance in older adults. One hundred five men participated in 1 of 3 age groups (18-28, 35-45, and 60-73). For each age group, subjects were classified as high or low in fitness on the basis of self-reported activity levels and the results of a submaximal bicycle ergometer test. A comprehensive battery of neuropsychological tests was administered to each subject, and older subjects scored significantly lower than the younger groups on most tests. Significant differences between high- and low-fit subjects were found only on tasks with heavy visuospatial demands, and these differences were most notable in the older adult group. These findings suggest that participation in aerobic exercise activity selectively preserves some cognitive functions that normally decline with age. The benefits of activity appear to be most evident on tasks that require visuospatial processing.     

When emotion does and does not impair performance: A Garner theory of the emotional Stroop effect

It takes people longer to name the ink colour of emotion or threat words than that of neutral words, the emotional Stroop effect (ESE). In three experiments with normal and patient populations, we show that the ESE is a special case of a generic attention model and effect entailed in Garner's speeded classification paradigm. Guided by the Garner model we demonstrate that task-irrelevant dimensions that differ in salience can produce the ESE and mimic it with neutral stimuli. When each word appears in a constant colour, as mandated in the correlation condition of the Garner design, the ESE is eliminated. This important result is consistent with the attention account of the ESE. We conclude that when emotion stimuli appear in a random fashion they interfere with task performance. However, when emotion stimuli are correlated with features of the ongoing task they help task performance not least due to their extreme salience.     

Do subitizing deficits in developmental dyscalculia involve pattern recognition weakness?

The abilities of children diagnosed with developmental dyscalculia (DD) were examined in two types of object enumeration: subitizing, and small estimation (5–9 dots). Subitizing is usually defined as a fast and accurate assessment of a number of small dots (range 1 to 4 dots), and estimation is an imprecise process to assess a large number of items (range 5 dots or more). Based on reaction time (RT) and accuracy analysis, our results indicated a deficit in the subitizing and small estimation range among DD participants in relation to controls. There are indications that subitizing is based on pattern recognition, thus presenting dots in a canonical shape in the estimation range should result in a subitizing‐like pattern. In line with this theory, our control group presented a subitizing‐like pattern in the small estimation range for canonically arranged dots, whereas the DD participants presented a deficit in the estimation of canonically arranged dots. The present finding indicates that pattern recognition difficulties may play a significant role in both subitizing and subitizing deficits among those with DD.     

Time estimation could be impaired in male,but not female adults with attention deficits

The ability to judge the passage of time is critical to behavioral regulation and planning and can be impaired among individuals with attention deficit. Time estimation was tested in young adults screened for attention deficit, based on scores of a self-report questionnaire for attention problems (CAARS), using a prospective reproduction paradigm. Four time intervals (3, 6, 12, and 24 s) were tested in two conditions: (1) reproduction of the duration of a visual stimulus and (2) reproduction of an empty time interval. A significant interaction between gender and group was found suggesting that males, but not females, with attention deficits made larger errors than controls. Males with attention deficits and both groups of females made larger underestimations of time judgement than control males.     

Depressed mothers' newborns show longer habituation and fail to show face/voice preference

Twenty neonates of depressed and nondepressed mothers failed to show an initial visual preference for their mother's versus a female stranger's face/voice. Subsequently, infants were habituated to their mother's face and voice. Infants of depressed mothers required 1/3 more trials and almost twice as long to habituate. A posthabituation test with their mother and a different female stranger revealed a preference for the stranger's face for 9 out of the 10 newborns of the nondepressed mothers. Again, the infants of depressed mothers displayed no visual preference. These findings reveal differences in depressed mothers newborns' speed of habituation and face/voice preferences. ©2002 Michigan Association for Infant Mental Health.     

The Impact of Cognitive Diversity on Crisis Negotiations

This paper reports on a series of experiments designed to assess the impact of grouping decision makers by level of cognitive complexity on the outcomes they attain in crisis negotiations. The participants—University of Maryland undergraduates who took roles in a simulated international hostage crisis—used a computer decision support system and a controlled network environment for communications. The goal of the experiments was to better understand the dynamics that lead certain types of groupings to have greater success in negotiations, and that lead certain groups of adversaries to achieve more mutually beneficial outcomes such as compromise and agreement. The findings point to a positive relationship between the level of homogeneity in cognitive complexity among decision makers and the achievement of positive outcomes in crisis negotiations.     

The differential effect of team members' trust on team performance: The mediation role of team cohesion

This study examines team performance as affected by various trusting relationships: trust between team members and the team's trust in their direct manager and in top management. Data for the study were collected from a survey of 690 professional elite athletes (belonging to 59 different sports clubs) playing in the regular, top professional Spanish leagues. The model was tested at the team level. Findings reveal that team member trust with respect to the different foci has both a direct and indirect effect on team performance, and that team player trust and cohesion play a mediating role. This study illustrates the dynamic relationship within teams, and, as such, trust among teammates mediates the relationship between trust in the coach as well as team cohesion in determining team performance. The implications for managing teams in other contexts are also evaluated.     

Rethinking free, libre and open source software

This special issue includes seven articles that make significant contribution to the literature pertaining to knowledge and public policy around Free, Libre and Open Source Software (FLOSS). Focusing on questions in two themes (i) motivation and organization and (ii) public policy, the articles in this volume develop new analytic models and report on new empirical findings, as an important step in bridging the wide gap that exists in public policy literature around FLOSS. Warning against rhetorical pitfalls that have been prevalent in FLOSS research, this introduction starts with a short history of FLOSS development, continues with a brief thematic literature review and review of the misconceptions surrounding FLOSS, and concludes with a first introduction of the articles that follow. He is part of the Dutch Institute of Government (NIG), the research school for public administration and political science. His research focuses on the organization of open source communities. He received two grants from the Netherlands Organization for Scientific Research (NWO) for research related to open source communities. The first grant was to study the interplay between intellectual property rights and open source communities. The results are published in Governing the Virtual Commons (Cambridge University Press, 2003). He has written numerous articles on open source, which have appeared in journals like Electronic Markets; Knowledge, Technology and Policy; and the International Journal of IT Standards & Standardisation Research. She received her Ph.D. in sociology from the University of York (UK) in 2004. Her Ph.D. research investigated the heterogeneity and contingency in the Free, Libre Open Source Software (FLOSS) social worlds, which is based on a constellation of hacking practices, from the sociological perspective. Her principal research interests center on FLOSS studies, Science and Technology Studies (STS), virtual communities and knowledge-sharing. Shay is also a fellow at The Information Society Project at the Yale Law School. Shay holds a B.Sc. in computer science and a B.A. in philosophy, magna cum laude, from Tel-Aviv University, and an M.A. from New York University where his interdisciplinary research thesis focused on the political economy of free and open source software and file sharing networks. Shay is an entrepreneur that co-founded two software start-up companies, and was involved for several years in cutting edge software research, combining open source and proprietary software.     

Brain hyper‐connectivity and operation‐specific deficits during arithmetic problem solving in children with developmental dyscalculia

Developmental dyscalculia (DD) is marked by specific deficits in processing numerical and mathematical information despite normal intelligence (IQ) and reading ability. We examined how brain circuits used by young children with DD to solve simple addition and subtraction problems differ from those used by typically developing (TD) children who were matched on age, IQ, reading ability, and working memory. Children with DD were slower and less accurate during problem solving than TD children, and were especially impaired on their ability to solve subtraction problems. Children with DD showed significantly greater activity in multiple parietal, occipito‐temporal and prefrontal cortex regions while solving addition and subtraction problems. Despite poorer performance during subtraction, children with DD showed greater activity in multiple intra‐parietal sulcus (IPS) and superior parietal lobule subdivisions in the dorsal posterior parietal cortex as well as fusiform gyrus in the ventral occipito‐temporal cortex. Critically, effective connectivity analyses revealed hyper‐connectivity, rather than reduced connectivity, between the IPS and multiple brain systems including the lateral fronto‐parietal and default mode networks in children with DD during both addition and subtraction. These findings suggest the IPS and its functional circuits are a major locus of dysfunction during both addition and subtraction problem solving in DD, and that inappropriate task modulation and hyper‐connectivity, rather than under‐engagement and under‐connectivity, are the neural mechanisms underlying problem solving difficulties in children with DD. We discuss our findings in the broader context of multiple levels of analysis and performance issues inherent in neuroimaging studies of typical and atypical development.