Microstructural organization of corpus callosum projections to prefrontal cortex predicts bimanual motor learning

The corpus callosum (CC) is the largest white matter tract in the brain. It enables interhemispheric communication, particularly with respect to bimanual coordination. Here, we use diffusion tensor imaging (DTI) in healthy humans to determine the extent to which structural organization of subregions within the CC would predict how well subjects learn a novel bimanual task. A single DTI scan was taken prior to training. Participants then practiced a bimanual visuomotor task over the course of 2 wk, consisting of multiple coordination patterns. Findings revealed that the predictive power of fractional anisotropy (FA) was a function of CC subregion and practice. That is, FA of the anterior CC, which projects to the prefrontal cortex, predicted bimanual learning rather than the middle CC regions, which connect primary motor cortex. This correlation was specific in that FA correlated significantly with performance of the most difficult frequency ratios tested and not the innately preferred, isochronous frequency ratio. Moreover, the effect was only evident after training and not at initiation of practice. This is the first DTI study in healthy adults which demonstrates that white matter organization of the interhemispheric connections between the prefrontal structures is strongly correlated with motor learning capability.     

Do not cross the line: Heuristic spatial updating in dynamic scenes

In two experiments, we examined the spatial integration of two viewpoints onto dynamic scenes. We tested the spatial-alignment hypothesis (which predicts integration by alignment along the shortest path) against the spatial-heuristic hypothesis (which predicts integration by observation of the left?Cright orientation on the screen). The stimuli consisted of film clips comprising two shots, each showing a car driving by. In Experiment 1, the dynamic scenes were ambiguous with regard to their interpretation: The cars could have been driving either in the same or in opposite directions. In line with the spatial-heuristic hypothesis, participants responded with ??same direction?? if the cars shared a screen direction. In Experiment 2, environmental cues disambiguated the dynamic scenes, and the screen direction of the cars was either congruent or incongruent with the depicted environmental cues. As compared with congruent dynamic scenes, incongruent dynamic scenes elicited prolonged reaction times, thus suggesting that heuristic spatial updating was used with congruent stimuli, whereas spatial-alignment processes were used with incongruent stimuli.     

Whichever way you choose to categorize, working memory helps you learn

There has been growing interest in the relationship between the capacity of a person's working memory and their ability to learn to categorize stimuli. While there is evidence that working memory capacity (WMC) is related to the speed of category learning, it is unknown whether WMC predicts which strategies people use when there are multiple possible solutions to a categorization problem. To explore the relationship between WMC, category learning, and categorization strategy use, 173 participants completed two categorization tasks and a battery of WMC tasks. WMC predicted the speed of category learning, but it did not predict which strategies participants chose to perform categorization. Thus, WMC does not predict which categorization strategies people use but it predicts how well they will use the strategy they select.     

Physical self-concept and disturbed eating attitudes and behaviors in French athlete and non-athlete adolescent girls: direct and indirect relations

This study aims to investigate the direct and indirect associations between physical self-subdomains, physical self-worth, global self-worth, and disturbed eating attitudes and behaviors among French non-elite athlete and non-athlete adolescent girls. A sample of adolescent girls including 50 ballet dancers, 41 basketball players, and 47 non-athletes was used in this study. Data obtained from the ballet dancer and basketball player subsamples revealed significant, sample-specific as well as common, direct relations between global and physical self-perceptions and disturbed eating attitudes and behaviors, as well as significant indirect relations (via global self-worth and physical self-worth) between specific physical self-perceptions and disturbed eating attitudes and behaviors. In contrast, no association was found between global and physical self-perceptions in the sample of non-athlete adolescent girls.     

The Role of Threat in Attitudes Toward Affirmative Action and Its Beneficiaries1

This set of two studies employed the integrated threat theory to examine attitudes toward affirmative action (AA). The first study found that opposition to the policy of AA was predicted by realistic threats, symbolic threats, and personal relevance; while attitudes toward the beneficiaries of AA were predicted by three of the four threat variables (symbolic threats, intergroup anxiety, and negative stereotypes), and in‐group identity. The second study replicated and expanded on the first study and found that the effects of several individual‐difference variables (racism, anti‐Black affect, and political conservatism) on opposition to AA were mediated by three of the threats in the integrated threat theory (realistic threats, symbolic threats, and negative stereotypes). The implications of the results are discussed.     

The dual role of ‘emergence’ in the philosophy of mind and in cognitive science

The concept of emergence is widely used in both the philosophy of mind and in cognitive science. In the philosophy of mind it serves to refer to seemingly irreducible phenomena, in cognitive science it is often used to refer to phenomena not explicitly programmed. There is no unique concept of emergence available that serves both purposes.     

When discounting fails: An unexpected finding

Two studies were designed to investigate the effects of prior information about plausible causes on subsequent attributions. In the Experiment 1, prior information was given about an internal and an external cause. It was predicted and found that the stronger an expectancy for a behavior, the more the behavior would be attributed to the cause that formed the basis of the expectancy. It was also predicted that (1) for facilitative causes, the stronger the expectancy based on a given cause, the less the behavior would be attributed to other causes (discounting), and (2)for inhibitory causes, the stronger the expectancy, the more the behavior would be attributed to other causes (augmenting). These predictions were not supported. It was suggested that discounting and augmenting did not occur because subjects had been given information about both causes which "locked in" their attributions to each cause. To test this explanation, a second study was undertaken in which observers were given information about only one cause. The results of Experiment 2 indicated that discounting and augmenting may only occur for attributions to causes about which no prior information is available.     

Reactions to stigmatized others: Response amplification vs sympathy

Four experiments examined the conditions under which responses to handicapped persons are characterized by sympathy or response amplification. The first two experiments tested the hypothesis that contact with a handicapped person would lead to amplified positive and negative responses in comparison to contact with a nonhandicapped person. The results indicated that mere contact was not sufficient to elicit response amplification. Instead, contact led to more positive evaluations of the handicapped than of the nonhandicapped other, regardless of whether she behaved in a positive or negative manner—a “sympathy” effect. The third and fourth experiments indicated that amplified positive and negative responses to the handicapped will occur when the behavior of a handicapped person is highly relevant to the evaluator. A two-stage model of responses to stigmatized others is proposed to account for these results.     

The Effects of Gender on Career Decision Problems in Young Adults

The authors investigated gender differences in psychological problems in the career decision making (CDM) process of young adults. Specifically, problems with decision anxiety, life-goal awareness, luck-fate orientation, authority orientation, and secondary gain motivation were investigated. Methodology involved administering the Career Decision Diagnostic Assessment (CDDA) instrument to 1,006 college students from four universities. Results indicated no gender differences in global levels of problems in CDM. Women reported more problems with life-goal awareness and authority orientation than did men. Men reported more problems with secondary gain motivations than did women. The results are discussed in terms of implications for gender-differentiated career counseling.     

A preliminary inquiry into the effect of potentially biasing information on judges and jurors in civil litigation

The American system of civil procedure presumes that judges and jurors will respond quite differently to potentially biasing material introduced into adjudicatory proceedings. Judges are assumed to possess a special capacity to control their subjective reactions to such material while jurors are perceived as incapable of such control. This article first reviews these presumptions and the differential treatment accorded judges and jurors by the system. An experiment in which judges and jurors were exposed to potentially biasing material in a civil trial is then described. The results suggest that judges and jurors may be similarly influenced by such exposure, regardless whether the biasing material is ruled admissible or inadmissible. The implications of these preliminary data—that judges may not possess the presumed special capacity to remain immune to bias—are briefly discussed.