Bodily Activity and Perceptual Activity

Knowledge of Results, Practice, and Sex: Anticipation of Coincidence Revisited

Knowledge of results (KR), practice, and sex were varied to examine their effects on anticipation of coincidence. Although these factors have been given empirical attention, the findings have been inconclusive and mixed, possibly for methodological reasons. Such issues were addressed, and an empirical attempt was made to rectify them. Using a Bassin Anticipation Timer, 30 men and 30 women were equally and randomly assigned to three groups: no KR, exact verbal KR, and verbal KR converted to a spatial representation. All subjects received 200 trials from which absolute error (AE), constant error (CE), and variable error (VE) were derived. Analysis of error terms yielded the following findings: KR and practice reduced error (AE and CE), practice alone reduced variability (VE), initial sex differences in AE and CE disappeared so there were no sex differences in performance, sex differences in variability were maintained over 200 trials. These findings are discussed in light of previous work, and possible explanations for the mixed findings are advanced.

Autokinesis and some conditions of fatigue

Effects of physical, mental, and vigilance fatigue on the autokinetic reports of 48 undergraduate students are described. Eight response measures were taken of the subjects with an apparatus that permitted recording of the apparent motion of the autokinetic stimulus in the same plane as the light source. Presence of the fatigue states was verified by independent measurements. Fatigue conditions facilitated quick and continuous perception of the autokinetic movements. The most perceptual complexity in the patterns of apparent motion was observed under mental fatigue followed by physical and vigilance fatigue, with least in the neutral condition.

Ego defenses and perceptual styles

This study explored similarities between Voth's personality construct (ego-close—ego-distant) and that of Witkin (field-dependent—field-independent), especially with reference to ego defenses. A measure of autokinesis, the Figure-drawing Test, the Rod-and-frame Test and the Defense Mechanisms Inventory were administered to 45 men and 52 women. The correlations between autokinetic scores and the Figure-drawing Test and Rod-and-frame Test scores were of low order and not significant. Correlations between Figure-drawing and Rod-and-frame Test scores and between combined Figure-drawing—Rod-and-frame scores and the subcategories of the Defense Mechanisms Inventory tended to confirm previous findings. Predicted relations between the autokinetic effect and ego defenses were obtained only for men. Other significant sex differences are presented. Possible explanations for these results are discussed.

Age and sex differences in the perception of autokinesis in children

216 boys and girls aged 7, 10 and 13 yr. reported autokinetic motion. Girls at age 7 reported less motion than boys but this difference decreased with increased age. Girls were slower to report movement than boys at age 7 and this also lessened with age. Comparison data from the literature are discussed.