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).     

An evaluation of response cost in the treatment of inappropriate vocalizations maintained by automatic reinforcement

In the current study, we examined the utility of a procedure consisting of noncontingent reinforcement with and without response cost in the treatment of inappropriate vocalizations maintained by automatic reinforcement. Results are discussed in terms of examining the variables that contribute to the effectiveness of response cost as treatment for problem behavior maintained by automatic reinforcement.     

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.     

Dispositional and situational goal orientations as discriminators among recreational and competitive league athletes.

The present study examined the relationship between individual goal orientation, motivational team climate, perceived sport competence, and league structure among 216 youth soccer players. It was predicted that competitive league teams would report higher ego-involvement and performance-oriented team climate and lower sport competence than recreational teams. Discriminant analyses indicated that only the mastery-oriented team climate variable differentiated competitive and recreational teams. Athletes who participated in recreational teams reported a greater degree of mastery-oriented climate than competitive league players. The results suggest that athletes' perceptions of situational rather than dispositional aspects of achievement goals are more highly affected by the playing structure present in youth sport teams. The possible psychological benefits derived from the development of a mastery-oriented team climate in sports are discussed.     

Can Bartlett’s repeated reproduction experiments be replicated?

Surprisingly, Bartlett's (1932) famous repeated reproduction experiments, in which he found systematically increasing errors in recall from the same people tested over time, have never been successfully replicated. Several studies have attempted partial replications, which were unsuccessful, and their authors concluded that the original observations might not be replicable. We conducted a study modeled closely after Bartlett's procedures: Subjects studied "The War of the Ghosts," took an initial test 15 min later, and then took a delayed test after 1 week. A follow-up test was conducted 6 months later on as many subjects as could be obtained. We did replicate Bartlett's results, in that (1) subjects forgot the story over delays but (2) introduced rationalization and distortion into their accounts of the story, with increases in the proportion of material distorted as retention interval increased. Subjects also imported new propositions at long delays, further confirming Bartlett's empirical observations and conclusions. Bartlett's repeated reproduction results can be replicated.     

Credible suggestions affect false autobiographical beliefs

False memory implantation studies are characterised by suggestions indicating that specific unremembered events occurred, attributing suggested events to a knowledgeable source (e.g., parents), and including true events that provide evidence that this source was consulted. These characteristics create a particular retrieval context that influences how individuals come to believe that false events occurred. Two studies used a variant of implantation methods to vary the proportion of events attributed to parents and the presence of true events within the suggestion. In Study 1 participants received six false events, and were told that all or some events came from parents. Participants told that all of the events came from parents formed more and stronger false beliefs. In Study 2 participants also received two true events, and a third group was told that half of the events came from their parents. Participants given the specific ratio ("half") endorsed more false beliefs, and beliefs between the other groups no longer differed. Across both studies participants told that some events came from parents reported stronger memory phenomenology. The effect of suggestions on false beliefs in implantation studies depends partly on the credibility of suggestions derived from providing information about the source of suggested events.