Contents Volume 117, 2004

Volume Contents

Contents Volume 117, 2004     

Contributions of striatal subregions to place and response learning

The involvement of different subregions of the striatum in place and response learning was examined using a T-maze. Rats were given NMDA lesions of the dorsolateral striatum (DLS), anterior dorsomedial striatum (ADMS), posterior dorsomedial striatum (PDMS), or sham surgery. They were then trained to retrieve food from the west arm of the maze, starting from the south arm, by turning left at the choice point. After 7 d of training, with four trials a day, a probe test was given in which the starting arm is inserted as the north arm, at the opposite side of the maze. A left turn would indicate a "response" strategy; a right turn, a "place" strategy. The rats were then trained for 7 more days, followed by a second probe test. Unlike rats in the other groups, most of the rats in the PDMS group turned left, using the response strategy on both probe tests. These results suggest that the PDMS plays a role in spatially guided behavior.     

A meta-analytic review of prospective memory and aging

A meta-analysis of prospective memory (PM) studies revealed that in laboratory settings younger participants outperform older participants on tests of both time- and event-based PM (rs=-.39 and -.34, respectively). Event-based PM tasks that impose higher levels of controlled strategic demand are associated with significantly larger age effects than event-based PM tasks that are supported by relatively more automatic processes (rs=-.40 vs. -.14, respectively). However, contrary to the prevailing view in the literature, retrospective memory as measured by free recall is associated with significantly greater age-related decline (r=-.52) than PM, and older participants perform substantially better than their younger counterparts in naturalistic PM studies (rs=.35 and.52 for event- and time-based PM, respectively).     

Resolution of conflicts between internal and external information sources on a time reproduction task: the role of perceived information reliability and attributional style

Erroneous knowledge of results (KR) that conflicts with other internal or external information sources is preferentially used and misguides performance on motor and mental timing tasks. Buekers et al. [J. Motor Behavior 26 (1994) 27] hypothesized that KR is used preferentially because participants deem it to be the most reliable information source. We tested this hypothesis in two experiments. We manipulated subjective reliability of information and information content and demonstrated that both reliability and content are assessed and used. In a third experiment we examined whether attributional style affected the use of internal and external information. While KR was present, attributional style was unrelated to performance. However, when erroneous KR was withdrawn, participants who scored high in internal attributional style or high in controllability showed more accurate performance. Whereas evaluation of information quality is explicit, information provided by the KR, whether accurate or not, may influence both implicit and explicit aspects of the tasks.     

Psychology,population, and reproductive behavior

This special section on international perspectives in psychology focuses on population issues and reproductive behavior across national and cultural boundaries, emphasizing the responsibility of psychologists and colleagues in related disciplines to generate and communicate culturally mindful findings likely to shape public health policy and improve human well-being. After considering the historical and policy context, it highlights internationally collaborative research projects in the Czech Republic, Egypt, Mexico, and the United States that address reproductive behavior, women's roles and status, responsible parenthood, and abortion legislation in terms of cultural context, gender equity, the needs of adolescents, and public health policy. The articles illustrate the importance of the cultural context within which psychological research is conducted and how psychology can be informed by international perspectives.     

The developmental ecology of urban males' youth violence

Data from a longitudinal study of 294 African American and Latino adolescent boys and their caregivers living in poor urban communities were used to test a developmental-ecological model of violence. Six annual waves of data were applied to evaluate the relations between microsystem influences of parenting and peer deviance (peer violence and gang membership), macrosystem influences of community structural characteristics and neighborhood social organization, and individual involvement in violence (level and growth). Structural equation modeling analyses showed that community structural characteristics significantly predicted neighborhood social processes. Parenting practices partially mediated the relation between neighborhood social processes and gang membership. Parenting practices was fully mediated in its relation to peer violence by gang membership. Gang membership was partially mediated by peer violence level in its relation to individual violence level. Although the overall set of relations does not satisfy mediation requirements fully in all instances, the model was validated for the most part, supporting a focus on a multilevel ecological model of influences on risk development.     

Natural scenes upset the visual applecart

The effortless ease of everyday vision seems to contradict numerous findings on the limited capacity of visual attention. However, natural scenes appear to escape the stringent limitations of attention that apply to seemingly far simpler stimuli. This astonishing result will oblige us to rethink the nature of visual attention and its limited capacity.     

Refutation of Poffenberger's inference: an existence proof and a countermodel

Interhemispheric relay time (IHRT) is inferred from simple (visual) reaction time (SRT) by subtracting SRTs in ipsilateral hand-field conditions from SRTs in contralateral hand-field conditions. This index, the "crossed-uncrossed differential" (CUD) is a synonym of IHRT in the current literature. The CUD has been shown to be significantly moderated by experimental variables, including attentional. One reason the CUD = IHRT hypostasy persists today is that no experimental manipulation has yet been able to generate a significantly negative CUD in a subject manifesting a significant positive CUD in classical conditions. We implemented an experimental manipulation, in SRT, consisting of increasing complexity of the response after the initial key press required at detection. In a very large scale single-case experiment, we found that the CUD thus went from significantly positive in classical SRT to significantly negative in the increased response load condition.     

Prevalence,and intellectual outcome of unilateral focal cortical brain damage as a function of age,sex and aetiology

Neurologists and neuropsychologists are aware that aging men are more at risk than women for brain damage, principally because of the well known male-predominant risk for cardiovascular disease and related cerebrovascular accidents. However, a disproportion in prevalence of brain damage between the sexes in childhood may be less suspected. Furthermore, sex-specific risk for other aetiologies of brain damage may be little known, whether in the pediatric or adult populations. Proposals of a sex difference in cognitive recovery from brain damage have also been controversial. Six hundred and thirty five "consecutive" cases with cortical focal lesions including cases of all ages and both sexes were reviewed. Aetiology of the lesion was determined for each case as was postlesion IQ. Risk was highly male prevalent in all age groups, with a predominance of cardiovascular aetiology explaining much of the adult male prevalence. However, several other aetiological categories were significantly male prevalent in juveniles (mitotic, traumatic, dysplasic) and adults (mitotic, traumatic). There was no sex difference in outcome (i.e., postlesion IQ) of these cortical brain lesions for the cohort as a whole, after statistical removal of the influence of lesion extent, aetiology and presence of epilepsy. Mechanisms potentially responsible for sex differences in prevalence, aetiology of brain damage, and recovery, are reviewed and discussed.