Contextual Interference in Movements of the Same Class: Differential Effects on Program and Parameter Learning

Contextual interference effects in motor learning usually were not found when the tasks to be learned presumably required the same generalized motor program (GMP) and differed only with regard to the movement parameters (see Lee, Wulf, & Schmidt, 1992; Magill & Hall, 1990). Thus, tasks requiring different motor programs (e.g., different relative timings) seemed to be a prerequisite for random practice to be more effective than blocked practice. However, the previous studies (that did not find random/blocked differences) used global error measures that confounded errors in relative timing and errors in absolute timing. In the present study, subjects practiced three movement patterns that had the same relative timing (requiring the same GMP) but different overall durations (requiring different parameters). Errors in relative timing and in absolute timing were assessed separately. The results indicate that random practice is more effective for the learning of relative timing (GMP learning) and less effective for the learning of absolute timing (parameter learning) than blocked practice. Preliminary ideas as to the reasons for this effect are discussed.     

Predicting the Completion of an Integrative and Intensive Outpatient Chronic Pain Treatment With the Personality Assessment Inventory

The X-zero distinction has been used as the operational definition of MMPI item subtlety in previous research. A consistent finding has been that the X items, which are obvious in terms of pathological content, can be faked whereas the more subtle zero items cannot be faked. The present study examined the relationship between instructional sets and endorsement patterns, using a more refined, comprehensive measure of item subtlety. Sixty (30 male, 30 female) subjects completed two MMPI protocols, one under a standard instructional set and the other under either a fake-good or fake-bad response set. Order of administration and sex were counterbalanced. In general, the findings for the subtle-obvious dimension paralleled the previous findings with the X-zero distinction. Endorsement of obvious items was a direct function of instructional set, whereas endorsement of subtle items was inversely related to instructional set. Because subtle items did not appear to measure the constructs for which they had been originally intended, other uses for subtle items were discussed.     

Cross-cultural generalizability of the Personality and Role Identity Structural Model (PRISM): Implications for trait and cultural psychology

The cross-cultural generalizability of the Personality and Role Identity Structural Model (PRISM; Wood & Roberts, 2006) was tested in the United States, Mexico, Malaysia, China, and Japan. Participants rated their general and role identities, as defined by the PRISM, using Big Five trait adjectives, then rated their personality states (i.e., role experiences) in various roles in multiple daily interactions for 14 days. Structural predictions based on the PRISM were supported in all five cultures. Cultural differences were limited and did not reflect cultural differences in individualism–collectivism, dialecticism, or cultural tightness. The results supported the cross-cultural generalizability of the PRISM and the merits of contextualized trait measures in the prediction of role experiences. Implications for trait and cultural psychology are discussed.     

Lower limb kinematic variability in dancers performing drop landings onto floor surfaces with varied mechanical properties

Elite dancers perform highly skilled and consistent movements. These movements require effective regulation of the intrinsic and extrinsic forces acting within and on the body. Customized, compliant floors typically used in dance are assumed to enhance dance performance and reduce injury risk by dampening ground reaction forces during tasks such as landings. As floor compliance can affect the extrinsic forces applied to the body, secondary effects of floor properties may be observed in the movement consistency or kinematic variability exhibited during dance performance. The aim of this study was to investigate the effects of floor mechanical properties on lower extremity kinematic variability in dancers performing landing tasks. A vector coding technique was used to analyze sagittal plane knee and ankle joint kinematic variability, in a cohort of 12 pre-professional dancers, through discrete phases of drop landings from a height of 0.2 m. No effect on kinematic variability was observed between floors, indicating that dancers could accommodate the changing extrinsic floor conditions. Future research may consider repeat analysis under more dynamic task constraints with a less experienced cohort. However, knee/ankle joint kinematic variability was observed to increase late in the landing phase which was predominantly comprised of knee flexion coupled with the terminal range of ankle dorsiflexion. These findings may be the result of greater neural input late in the landing phase as opposed to the suggested passive mechanical interaction of the foot and ankle complex at initial contact with a floor. Analysis of joint coordination in discrete movement phases may be of benefit in identifying intrinsic sources of variability in dynamic tasks that involve multiple movement phases.     

Reference frames during the acquisition and development of spatial memories

Four experiments investigated the role of reference frames during the acquisition and development of spatial knowledge, when learning occurs incrementally across views. In two experiments, participants learned overlapping spatial layouts. Layout 1 was first studied in isolation, and Layout 2 was later studied in the presence of Layout 1. The Layout 1 learning view was manipulated, whereas the Layout 2 view was held constant. Manipulation of the Layout 1 view influenced the reference frame used to organize Layout 2, indicating that reference frames established during early environmental exposure provided a framework for organizing locations learned later. Further experiments demonstrated that reference frames established after learning served to reorganize an existing spatial memory. These results indicate that existing reference frames can structure the acquisition of new spatial memories and that new reference frames can reorganize existing spatial memories.     

Working memory for patterned sequences of auditory objects in a songbird

The capacity to remember sequences is critical to many behaviors, such as navigation and communication. Adult humans readily recall the serial order of auditory items, and this ability is commonly understood to support, in part, the speech processing for language comprehension. Theories of short-term serial recall posit either use of absolute (hierarchically structured) or relative (associatively structured) position information. To date, neither of these classes of theories has been tested in a comparative auditory model. European starlings, a species of songbird, use temporally structured acoustic signals to communicate, and thus have the potential to serve as a model system for auditory working memory. Here, we explore the strategies that starlings use to detect the serial order of ecologically valid acoustic communication signals and the limits on their capacities to do so. Using a two-alternative choice operant procedure, we demonstrate that starlings can attend to the serial ordering of at least four song elements (motifs) and can use this information to classify differently ordered sequences of motifs. Removing absolute position cues from sequences while leaving relative position cues intact, causes recognition to fail. We then show that starlings can, however, recognize motif-sequences using only relative position cues, but only under rigid circumstances. The data are consistent with a strong learning bias against relative position information, and suggest that recognition of structured vocal signals in this species is inherently hierarchical.     

Increasing positive intergroup contact

We tested an intervention designed to correct negative expectations about inter-racial interactions, increase the positivity of those interactions, and increase inter-racial friendships. In Study 1 (n = 58) White college students watched videotapes depicting an inter-racial friendship and either did or did not write about a similar experience. Participants who wrote about a similar experience expected and actually had a more positive inter-racial interaction. In Study 2 (n = 99) White college students watched videotapes depicting an inter-racial or same-race friendship and either did or did not write about a similar experience. Those who saw the inter-racial video and wrote about a similar experience had a more positive inter-racial interaction and initiated more inter-racial friendships in the following weeks than participants in the other conditions.     

Group transformation: How demonstrability promotes intra-group cooperation in social dilemmas

Intra-group cooperation in a social dilemma is increased after a group has discussed and reached a decision, especially if the dilemma is easily understood (‘demonstrable’). This paper examines how demonstrability affects the decision of a group that consists entirely of participants who are initially non-cooperative. Thirty-eight 6-person groups with unanimous prior preference for cooperation or non-cooperation discussed a prisoner’s dilemma before making a group decision. When demonstrability was low groups reflected the prior (either cooperative or non-cooperative) preferences of their members. When demonstrability was high we found that groups showed no effect of prior preference. Specifically, groups of prior non-cooperators made more cooperative group decisions and subsequently their members remained cooperative when asked to express preferences individually. The combined advantages of group process and high demonstrability for facilitating optimal cooperation are discussed.     

Consuming experience: Why affective forecasters overestimate comparative value

The hedonic value of an outcome can be influenced by the alternatives to which it is compared, which is why people expect to be happier with outcomes that maximize comparative value (e.g., the best of several mediocre alternatives) than with outcomes that maximize absolute value (e.g., the worst of several excellent alternatives). The results of five experiments suggest that affective forecasters overestimate the importance of comparative value because forecasters do not realize that comparison requires cognitive resources, and that experiences consume more cognitive resources than do forecasts. In other words, because forecasters overestimate the extent to which they will be able to think about what they did not get while experiencing what they got.     

Concurrent reinforcement schedules for problem behavior and appropriate behavior: experimental applications of the matching law

This study evaluated how children who exhibited functionally equivalent problem and appropriate behavior allocate responding to experimentally arranged reinforcer rates. Relative reinforcer rates were arranged on concurrent variable-interval schedules and effects on relative response rates were interpreted using the generalized matching equation. Results showed that relative rates of responding approximated relative rates of reinforcement. Finally, interventions for problem behavior were evaluated and differential reinforcement of alternative behavior and extinction procedures were implemented to increase appropriate behavior and decrease problem behavior. Practical considerations for the application of the generalized matching equation specific to severe problem behavior are discussed, including difficulties associated with defining a reinforced response, and obtaining steady state responding in clinical settings.