Redundancy: a similar principle in independent adaptation techniques

The present study examined the similarities between four auditory adaptation techniques to determine whether the effects were correlated. The four adaptation techniques compared were: Simultaneous Dichotic Loudness Balance technique (SDLB; Hood, 1950), Magnitude Estimated Binaural technique (MEB; Botté, Canévet, & Scharf, 1982), Magnitude Estimated Monaural technique, (MEM; Weiler, Sandman, & Pederson, 1981), and the Monaural Reaction Time technique (RT; Davis & Weiler, 1976). Results did not show significant correlations between the four techniques, except (r = 0.39) between MEB and MEM procedures. This correlation was much less than the reliability of the measures would allow (r = 0.98 and r = 0.99, respectively). Thus, it appears that the different methods either produced different adaptation effects or measured different aspects of auditory adaptation. The normal ear apparently shows several forms of adaptation, which reduces the perceptual strength of a continuing stimulus, in favor of an intermittent, less redundant one.     

Effects of head restraint on signal detectability in simultaneous and successive vigilance tasks

Dittmar, Warm, and Dember (1985) suggested that visual parallax may lead to declines in perceptual sensitivity over time in spatial vigilance tasks involving comparative judgments. The present study tested this possibility by restraining subjects' head movements during a 1-hr vigil in which comparative (simultaneous task) or absolute (successive task) judgments of line length were necessary for signal detection. Under free-viewing conditions, perceptual sensitivity declined over time with both types of tasks. Head restraint eliminated the sensitivity decrement in both cases. The results highlight signal quality as a crucial determinant of perceptual decrements in sustained attention.     

The Social Psychology of Caregiving: Physical and Psychological Costs of Providing Support to the Disabled1

The emphasis of much of the existing research on social support-health relationships has been on the availability and impact of support on the recipient, but social psychologists have paid little attention to the costs to the caregiver of providing that support. In an earlier study (Schulz & Decker, 1985), we found that the long-term coping of individuals experiencing chronic disability as a result of spinal-cord injury was facilitated by the availability of a primary support person, or caregiver. In this study we examined the determinants of well-being of the primary caregiver of the middle-aged and elderly spinal-cord-injured persons. Psychological well-being, life satisfaction, and depression were the dependent measures. The availability of social support, social contact, and feelings of control over one's life were important determinants of caregiver well-being, even after controlling for health and income. In addition, the amount of time spent each day assisting the disabled person was a strong independent correlate of depression, and the extent to which the caregiver felt burdened by the victim was significantly and negatively related to life satisfaction. These results are discussed in the context of a comprehensive stress-coping model. Since data were available from both disabled individuals and their primary support persons, we had the unique opportunity to compare the perspectives of both those giving and receiving daily care. We found no relationship in levels of psychological well-being and depression reported by the disabled person and caregiver; however, caregivers attributed to the victims affective levels similar to their own.     

Study of neuromotor reaction times under the influence of thyrotropin-releasing hormone

Neuromotor reaction times (simple, choice, and decision) were measured when Thyrotropin-releasing hormone (TRH) was administered intravenously to nine healthy men in a double-blind study. Measurements were made of simple reaction time, choice reaction time, and decision time for each subject at various intervals over a 54-hr. period. Given the observed inherent interaction of the drug with the long time used (54 hr.), most analyses were conducted across separate time epochs. Injected subjects showed inhibition in the normal improvement of simple reaction time (which occurs with practice), and they reduced the time required to make a decision. Choice reaction time, however, remained unchanged across the drug-nondrug experimental conditions.     

Visual dominance in olfactory memory

The object of the present study was to verify the emergence of a 'visual dominance' effect in memory tests involving different sensory modes (sight and smell), brought about the preattentive mechanisms which select the visual sensory mode regardless of the recall task.