Changes in spinal excitability during dual task performance

ABSTRACT The authors investigated how the nervous system responds to dual task performance. Because dual tasking is associated with greater postural challenges, it was hypothesized that spinal excitability would be reduced when simultaneously performing 2 tasks. For this experiment, participants maintained a lying or standing posture with or without performing a concurrent cognitive task (i.e., reacting to an auditory tone). Spinal excitability was assessed by eliciting the soleus Hoffmann reflex (H-reflex). Results indicated that the H-reflex was 6.4 ± 2.3% smaller (p = .011) when dual compared to single tasking. The reduced H-reflex amplitude, indicating a depressed spinal excitability, when dual tasking is suggested to reflect a neural strategy that individuals adopt to maintain postural stability when cognitive resources are divided between 2 concurrent tasks.     

Memory conformity and the perceived accuracy of self versus other

Here, we demonstrate that the decision to conform to another person’s memory involves a strategic trade-off that balances the accuracy of one’s own memory against that of another person. We showed participants three household scenes, one for 30 s, one for 60 s, and one for 120 s. Half were told that they would encode each scene for half as long as their virtual partner, and half were told that they would encode each scene for twice as long as their virtual partner. On a subsequent two-alternative-forced choice (2AFC) memory test, the simulated answer of the partner (accurate, errant, or no response) was shown before participants responded. Conformity to the partner’s responses was significantly enhanced for the 30-s versus the 60- and 120-s scenes. This pattern, however, was present only in the group who believed that they had encoded each scene for half as long as their partner, even though the short-duration scene had the lowest baseline 2AFC accuracy in both groups and was also subjectively rated as the least memorable by both groups. Our reliance on other people’s memory is therefore dynamically and strategically adjusted according to knowledge of the conditions under which we and other people have acquired different memories.     

An Indicator of Suicidal Ideation on the Rorschach Test

We examined the impact of patient- and therapist-rated alliance developed during psychological assessment on the subsequent alliance measured early and late in formal psychotherapy. We hypothesized that a working alliance developed during psychological assessment conducted from a collaborative therapeutic model of assessment (TMA; Finn &; Tonsager, 1992, 1997; Fischer, 1994) between the patient and therapist would carry into formal psychotherapy. We also hypothesized that alliance for those patients receiving a TMA would be significantly greater than patients receiving psychological testing as usual. To test this hypothesis, we administered the Combined Alliance Short Form-Patient Version (Hatcher &; Barends, 1996) and the Combined Alliance Short Form-Therapist Version (Hatcher, 1999) to a sample of outpatients and their therapists at the end of the assessment feedback session, early, and late in psychotherapy. The hypotheses were supported as alliance scales rated at the assessment feedback session demonstrated positive and significant relationships with alliance throughout formal psychotherapy and in relation to a control group. The clinical utility and research implications of these findings are discussed.     

Organizational reward systems: Implications for climate

This study investigated the role of systematically different organizational reward structures upon individual perceptions of the reward climate. Nurses in a naval hospital worked for the same supervisors but were subject to either tenure-contingent (N=73) or behavior-contingent (N=50) reward systems. No differences in perceived reward climate were found between the two groups. In the tenure-contingent group, job attitudes reflected individual characteristics rather than perceived climate. The opposite relationship was found for the behavior-contingent group.Support for this research was provided under Office of Naval Research Contract RR942-08-01 NR 170-915. Opinions expressed are those of the author. No endorsement by the Department of the Navy has been given, nor should it be inferred. Portions of the study were conducted while the author was at the Naval Health Research Center in San Diego. The author would like to thank R. J. Bullock, Mark C. Butler, L. R. James, and R. D. Pritchard for their helpful comments and assistance.