Duration of negative practice and the reduction of leg pounding of a traumatically brain-injured adult

This study evaluated the relative efficacy of long (1 minute) and short (15 seconds) durations of negative practice for reducing self-stimulatory leg pounding of a traumatically brain-injured adult. In individual social skill training classes, long negative practice and short negative practice were administered concurrently in an alternating treatments design. Generalization of treatment effects outside of training sessions was assessed during the client's lunch period. The results revealed that both durations of negative practice were equally effective in reducing leg pounding during training sessions. However, the effects of training did not generalize to settings in which the practice contingency was not enforced. Pounding was more frequent and negative practice somewhat less effective during periods of high social stimulation.     

Specification of direction and duration during programming of discrete sliding movements

Summary Two experiments on duration programming of a discrete sliding movement in choice reactions are reported. In the first experiment it was examined whether duration of movement might be preprogrammed when varied across sessions. The result suggested that programming of movement duration is dependent on direction uncertainty. Experiment 2 used the movement precue technique in an attempt to further examine programming of movement duration and direction. Movement duration, movement direction, movement form and foreperiod duration were manipulated. When duration was not precued, a duration effect was found, while precueing resulted in disappearance of the duration effect, demonstrating that duration of sliding movements can be preprogrammed. Moreover, (pre)programming duration was independent of direction uncertainty, supporting an independent order notion of programming of these response variables. Evidence that motor preparation comprises different processing stages was derived from the additive effects of foreperiod duration and of the movement variables duration and direction.     

Clinician experiences of homework in couples and family therapy: A survey of perceived impact on the working alliance

The process of engaging clients in homework assignments has been studied extensively in research settings, but rarely have the challenges in the implementation of the science been considered in couples and family therapy. A survey was conducted of 226 clinicians regarding (1) their experience of homework adherence (quantity and quality) with couple and family clients, and (2) their experience of the impact of homework non-completion (IHN) on the working alliance. Clinicians working with families reported less overall homework quantity and quality. However, across both couples and family clients, more negative IHN was reported among clinicians experiencing less homework quantity, both in terms of IHN bond (couple ρ = 0.71, p < 0.001; family ρ = 0.78, p < 0.001) and IHN agreement (couples ρ = 0.25, p < 0.001; ρ = 0.19, p = 0.006), and among clinicians with fewer years of clinical experience (r = 0.19, n = 136, p < 0.05). The present findings suggest that, in the context of couples and family therapy, there is a risk of perceived negative IHN on the working alliance. There would be merit to future investigations examining the processes of facilitating homework engagement within the context of a strong working alliance.     

Fragile promise: The role of justification in promise-breaking

People who consider themselves moral sometimes use self-serving justifications to rationalize their selfish behaviours. Previous studies have tested the role of ambiguity in justifying wrongdoings, but it remains unclear whether ambiguity also plays a role in justifying promise-breaking behaviour and whether heterogeneity exists. To investigate justification in promise-breaking, we introduced a new experimental paradigm called the card-guessing task and used hierarchical cluster analysis to classify participants based on their promise-breaking decisions in unambiguous and ambiguous conditions. Experiment 1 revealed three clusters of solutions: Cluster 1 always kept their promises (i.e., keepers); Cluster 2 only exploited the vague promises and broke their promises in the ambiguous condition (i.e., intermediates); Cluster 3 tended to take advantage of vague promises and broke their promises irrespective of ambiguity (i.e., breakers). Experiment 2 confirmed that participants in the three clusters differed in their norm-abiding preferences and social value orientations. Keepers were more altruistic and had a stronger sense of norm compliance than intermediates and breakers. In conclusion, our study demonstrates that self-serving justifications were more likely to be employed by people who are moderately sensitive to deviation from social norms, which has implications for strategic interventions and policy formulation concerning unethical behaviour.     

Differential payoff and locus of selectivity in a visual memory task

Two experiments were run to investigate the locus of selectivity in a visual memory task involving differential payoff for letters correctly recalled: Major variables consisted of value instructions given before or after the exposure of a display, the ratio of high to low value, and exposure duration. The results showed that Ss make more correct reports of higher value than of lesser value, whether value instructions are given before or after the display. Furthermore, overall performance and extent of selectivity increase with increasing exposure time, but more for the before than the after conditions of instruction. These results suggest that selectivity occurs both during perception and retention and during recall.     

Visual on- and off-latencies and handedness

Ten Ss served in this experiment, five right-handed and five left-handed. Every S was tested in a perceived-order situation and by the up-and-down method to determine the relative on-latency for a visual test stimulus. i.e, (ON-Lat for lest stimulus involving right hemisphere- ON-Lat for standard stimulus involving left hemisphere) and to determine a similarly defined relative off-latency for the same test stimulus. The algebraic difference between the relative on-latency measure and the relative off-latency measure was then found. Data from a previous study had suggested that this “on-off difference” was characteristically positive for left-handed Ss and negative for right-handed Ss. The present data agree. The left-handed Ss were found to differ significantly from the right-handed Ss in the magnitude of the on-off difference. This outcome appears important as a possible clue to functional interhemispheric differences related to handedness.     

The number of ways to label a structure

It has been observed that the number of different ways in which a graph withp points can be labelled isp! divided by the number of symmetries, and that this holds regardless of the species of structure at hand. In this note, a simple group-theoretic proof is provided.This work was supported by Grant MH 10834 from the National Institute of Mental Health.