Electromyograph responses and performance success estimates as a function of internal-external control.

For 12 externally scoring college women, marginally significant correlations of EMG recordings with self-estimates of success in tensing forearm muscles (-.50) and with success in relaxing these muscles (-.54) were obtained. Similar correlations for 12 internally scoring women were much smaller. Analysis of variance of means had indicated no differences in ability of these groups to control muscles of the forearm.     

Variation in performance on auditory and visual monitoring tasks as a function of signal and stimulus frequencies

Observers were required to detect double jumps of a diffuse light spot jumping in a circular pattern and more intense noise pulses in a pulse train. Seven groups performed at different combinations of stimulus and signal frequencies, higher signal frequency/stimulus frequency ratios, and lower stimulus frequencies. Stimulus frequency was a more potent determiner of performance than signal frequency, and performance was not invariant within a given signal frequency/stimulus frequency ratio. Correlations of dependent measures were also examined.-Results are discussed with reference to various theories of vigilance behavior.     

Helping as a function of empathic responses and sociopathy

The present study reports two experiments which investigated helping as a function of empathic anxiety (anxiety in response to modeled distress) and individual differences in sociopathic tendencies. The first experiment concerned the effects of empathic anxiety, sociopathy, and perceived similarity/dissimilarity to a distressed person on helping. As predicted, subjects who experienced high levels of empathic anxiety helped more than subjects who experienced low levels of empathic anxiety. High sociopathic subjects experienced lower levels of empathic anxiety and helped less than did low sociopathic subjects. However, a path analysis disclosed that sociopathy's relationship to helping was not due to (or mediated by) empathic anxiety. The similarity manipulation did not influence empathic anxiety or helping. In the second experiment, subjects were classified as primary or secondary sociopaths (based on their levels of trait anxiety). As in the first experiment, empathic anxiety and sociopathy were significantly related to helping. Primary sociopaths displayed less empathic anxiety than secondary sociopaths, but the two groups did not differ in their willingness to help. Thus, in neither study could the sociopath's behavior be explained by empathic anxiety. The discussion concerned empathy as a mediational variable in helping and the role of personality variables in helping. A post hoc explanation of the sociopath's behavior, based on Schwartz' theory of the characteristics of helpers, was proposed.     

Inhibition of return: sensitivity and criterion as a function of response time

Inhibition of return (IOR) refers to a mechanism that results in a performance disadvantage typically observed when targets are presented at a location once occupied by a cue. Although the time course of the phenomenon--from the cue to the target--has been well studied, the time course of the effect--from target to response--is unknown. In 2 experiments, the effect of IOR upon sensitivity and response criterion under different levels of speed stress was examined. In go/no-go and choice reaction time tasks, IOR had at least 2 distinct effects on information processing. Early in target processing, before sufficient target information has accrued, there is a bias against responding to cued targets. Later, as target information is allowed to accrue, IOR reduces sensitivity to the target's nonspatial feature. Three accounts relating to the early bias effect of IOR and the late effect of IOR on sensitivity are offered.     

Variation in coordination of a discrete multiarticular action as a function of skill level

The authors investigated coordination modes that emerged as a function of the interaction between skill level and task constraints in a multiarticular kicking action. Five skilled, 5 intermediate, and 5 novice participants attempted to satisfy specific height and accuracy constraints in kicking a ball over a barrier. Skilled and intermediate groups demonstrated a functional coordination mode involving less joint involvement at the proximal joints and greater joint involvement at distal joints, mimicking a chip-like action in soccer. Conversely, the novice group tended to produce larger ranges of motion throughout the kicking limb in a driving-like kicking action. Key differences were also found for task outcome scores, joint angle-angle relations, and ball-trajectory plots between the skilled and intermediate groups and the novice group. Findings from this study demonstrated that joint involvement during this discrete multiarticular action is a function of skill level and task constraints rather than a consequence of a global freezing-freeing strategy suggested in some previous research. The authors also highlight the merit of using a model of the acquisition of coordination in examining how coordination modes for multiarticular actions differ as a function of skill.     

Psychomotor performance as a function of time of day

Previously reported data on mirror tracking were reexamined for time-of-day (TOD) effects on performance and for the interaction of these effects with sex and practice effects. Analyses showed a significant linear decline of mean score from 0900 through 1300 hours, a sharp postlunch recovery at 1400 hours, and another significant linear decline from 1400 through 1700 hours. These effects were orthogonal to sex and practice effects. Discussion emphasized the importance of control for time of day in experimental design and suggested several hypotheses about the decremental effects of time of day.     

Binocular summation in the evoked cortical potential

Computer-averaged evoked potentials were recorded from six subjects presented with flashes under conditions of binocular and monocular viewing, with a device fitted over each eye to produce ganzfeld conditions. Tests were run with red light and with blue. Analysis of the evoked potentials indicates a substantially larger amplitude with binocular stimulation.     

Block-design performance as a function of hue and race

The block-design subtest of the WISC was presented in two forms, the standard red/white and an alternative blue/yellow, to two groups of fourth- and fifth-grade children. Twenty black children and 20 white children performed the red/white task with no significant differences between their scores. Another 20 black and 20 white children performed the blue/yellow task showing a significant interracial difference. Within the group of black children there was also a significant difference between the red/white design scores and the blue/yellow design scores. It is proposed that genetically determined differences in the pigmentation of the fundus oculi account for these results.     

Cerebral evoked responses in schizophrenia

Results of previous studies of evoked responses in schizophrenic disorders are reviewed, and data from a new study of somatosensory recovery functions in schizophrenia are presented. Subjects in the latter study were 18 schizophrenic patients and 18 nonpatients matched for age and sex. Latencies and amplitudes of eight consecutive evoked-response peaks were measured. Only one amplitude and one latency of the response to the first stimulus discriminated between patients and controls, whereas four amplitudes and three latencies of the second response did so. Amplitude recovery was less in patients, whereas latency recovery was greater. The data verified previous findings of impaired amplitude recovery in schizophrenia, but did not confirm previous findings of increased amplitude in response to a single stimulus. Evoked-response deviations so far determined are not specific to schizophrenic disorders, inasmuch as they have been found in several other psychiatric syndromes. The data are in accord with the idea that psychiatric disorders involve deviant cerebral processing of sensory information.     

Progamming time in serial tapping responses as a function of pathway constraint

Summary This study varied the accuracy demand within a linear series of targets to investigate the effect of movement-pathway constraints on response-programming time. Sidaway, Christina, and Shea (1988) have suggested that constraints placed upon movement initiation by the demand for response precision may play an important role in determining the length of the programming process. By varying the subtended angles of a series of three targets, this experiment tested the specific prediction of Sidaway et al. that programming time may be a function of the target, within a line of targets, that subtends the smallest angle at the start position. It is this target that demands the greatest precision in the movement pathway. Subjects participated in a series of conditions in which the size and placement of the target that imposed the maximal constraint was varied. In each condition the subjects were required to strike a series of three targets with a stylus in a simple reaction-time paradigm. Analysis of the reaction-time results revealed a significant effect of size of constraint, but no effect of position of constraint. Analysis of the movementtime data dispelled movement-duration and movement-velocity interpretations of the results and intimated a possible online trajectory-correction process.Portions of these data were first presented at the Annual Meeting of the Psychonomic Society in Atlanta, Georgia, November 1989.