Effects of graded doses of alcohol on speed-accuracy tradeoff in choice reaction time

The inconsistency of previous results concerning the effects of alcohol on reaction time (RT) may be related to possible tradeoffs between speed and accuracy. In the present experiment, complete speed-accuracy tradeoff functions were generated for each of five doses of alcohol (0-1.33 ml/kg) in a choice RT task. Such functions permit RT differences resulting from changes in performance efficiency to be distinguished from those due to changes in subjects’ speed accuracy criteria. Increasing doses of alcohol produced a progressive decrease in the slope parameter of linear equations fit to the speed-accuracy data, but did not significantly alter the intercept of the functions with the RT axis. Thus, alcohol reduced performance efficiency by decreasing the rate of growth of accuracy per unit time. A change in speed-accuracy criterion was combined with the decrease in efficiency at the highest alcohol dose.     

Braille learning: Relative importance of seven variables

A number of experiments have demonstrated that the learning of braille is affected by a variety of factors. The present experiment was carried out to determine the relative importance of these variables for braille learning. The variables were stimulus set discriminability (high, low), study modality (visual, haptic), test modality (visual, haptic), study size (large vs standard braille cell), test size (large vs standard braille cell), study rate (5 or 10 seconds per item), and test rate (5 or 10 seconds per item). The results showed that study modality, stimulus set discriminability, and test modality were the variables mainly responsible for differences in performance during acquisition. Some practical and theoretical implications of these results are considered.     

Acute neuropsychological consequences of coronary artery bypass surgery

This study examines a series of coronary artery bypass patients (CABS) for neuropsychological and regional cerebral blood flow (RCBF) changes at 8 days and 8 weeks post surgery. Seventy-three percent were found to have moderate or severe neuropsychological deficits at 8 days post operation and 37% at 8 weeks post surgery. A comparison group of major vascular and thoracic surgery patients was also found to have a significant proportion of neuropsychological deficit following surgery. The RCBF assessments indicated a significant drop in mean RCBF at 8 days post surgery in the coronary artery bypass group which did not persist to 8 weeks. The comparison group showed no changes in RCBF following surgery. The findings suggest different patterns of recovery and origins of the neuropsychological deficit in the two groups and emphasize the need for appropriate control groups in studies examining the cortical effects of extracorporeal circulation. In addition, the project received generous support from the special trustees of the Middlesex Hospital.     

Transcendental meditation, mindfulness, and longevity: an experimental study with the elderly

Can direct change in state of consciousness through specific mental techniques extend human life and reverse age-related declines? To address this question, 73 residents of 8 homes for the elderly (mean age = 81 years) were randomly assigned among no treatment and 3 treatments highly similar in external structure and expectations: the Transcendental Meditation (TM) program, mindfulness training (MF) in active distinction making, or a relaxation (low mindfulness) program. A planned comparison indicated that the "restful alert" TM group improved most, followed by MF, in contrast to relaxation and no-treatment groups, on paired associate learning; 2 measures of cognitive flexibility; mental health; systolic blood pressure; and ratings of behavioral flexibility, aging, and treatment efficacy. The MF group improved most, followed by TM, on perceived control and word fluency. After 3 years, survival rate was 100% for TM and 87.5% for MF in contrast to lower rates for other groups.     

The influence of visual texture density gradients on relative distance judgements

A hypothesis derived from J. J. Gibson's psychophysical theory of space perception was tested. Subjects made monocular relative distance judgements by moving a marker to the apparent physical mid-point between two other fixed markers which were placed on a surface along the subjects' line of sight. Judgements were significantly influenced by the texture density gradients of stimulation derived from the surface over which they were made.     

FACTORS THAT AFFECT NONTRADITIONAL VOCATIONAL ENROLLMENT AMONG WOMEN

This study identified the internal (personality) and external (social support) factors that differentiate women who enter male-dominated (Nontraditional) vocational training programs from those who only consider entering such programs (Considereds) and from those who enter female-dominated (Traditional) programs. Four hundred seventy women who were enrolled in California vocational training programs and were stratified on both social class and type of vocational training site completed a self-administered questionnaire covering (1) demographic/family background, (2) social support/encouragement from others, (3) peer experience with nontraditional programs, and (4) personality and sex-role orientation results revealed that the student subgroups differed most significantly in the amount of support, encouragement, and discouragement they received from the important others in their lives. Nontraditional students differed from Traditional students primarily in the support of female friends and family members, and from Considereds in encouragement from school personnel Recommendations are made for steps that can be taken to foster equality of educational opportunity.