Sex task and processing strategy effects in hemispheric alpha asymmetries for the recall and recognition of arousal words: results from perceptual and motor tasks in males and females

Hemispheric alpha asymmetries of males and females were observed during perceptual and motor tasks requiring recall and recognition of words controlled for level of arousal (positive, negative, and neutral). Verbal reports of individual processing strategy were collected and analyzed relative to hemispheric alpha ratios. Results showed greater alpha suppression in the left relative to right hemisphere for recall as compared to recognition tasks and for word presentation when contrasted with motor conditions. High positive correlations were found between narrative report of processing strategy and hemispheric alpha data. A separate analysis revealed that seven subjects identified as highly analytic processors showed greater alpha suppression in the left relative to right hemisphere across tasks, conditions, and stimuli than did seven highly visual processors who, in contrast, demonstrated greater right hemispheric alpha suppression. Task difficulty and individual differences in processing style that modify cerebral laterality effects are discussed.     

Object-Based Visual Selection: Evidence From Perceptual Completion

A large body of evidence suggests that visual attention selects objects as well as spatial locations. If attention is to be regarded as truly object based, then it should operate not only on object representations that are explicit in the image, but also on representations that are the result of earlier perceptual completion processes. Reporting the results of two experiments, we show that when attention is directed to part of a perceptual object, other parts of that object enjoy an attentional advantage as well. In particular, we show that this object-specific attentional advantage accrues to partly-occluded objects and to objects defined by subjective contours. The results corroborate the claim that perceptual completion precedes object-based attentional selection.     

Dichotic ear preferences of stuttering children and adults.

39 stutterers and 39 normal speakers indicated their ear preferences for dichotically presented words and digits. A single response mode for both dichotic words and digits was selected to study speech perception. Stutterers showed significantly less of the normal right-ear preference for dichotic words and digits than non-stutterers. The proportion of stutterers who failed to demonstrate a right-ear preference for dichotic words was significantly greater than for non-stutterers. 18% of the stutterers and none of the non-stutterers showed reversed or a left-ear preference for dichotic digits. Although non-stuttering children and adults performed alike on the dichotic tasks, the right-ear dichotic-words scores of stuttering children were significantly smaller than those of adult stutterers. The results are related to an early notion that stuttering may be related to mixed dominance and recent evidence showing that large percentages of older stuttering children show spontaneous remission of stuttering.     

Voluntary attention and the spacing effect

Three experiments were done to test the hypothesis that the spacing effect results from a voluntary decision by the subject to pay little attention to the second presentation (P₂) of an item when it occurs shortly after the first (P¹)- In all three experiments, the spacing of repetitions was varied. In Experiment I, allocation of attention was manipulated by pairing P₂ of some pictures with a signal that indicated high payoff for later retention. In Experiment II, attention was controlled more directly by requiring the subject, in one condition, to recite words aloud. In both experiments, the dependent variable was judged frequency. In neither experiment did the effect of the attention manipulation interact with that of the spacing of repetitions. In Experiment III, the number of eye fixations given a picture was taken to be a measure of attention. The number of fixations dropped from P₁ to P₂ to P₃, but was unaffected by the spacing of repetitions. The experiments provide no support for a voluntary attention explanation of the spacing effect.     

The interference of various word parts on color naming in the Stroop test

This study compared the interfering effects of various word parts on performance of the Stroop task. In different conditions, the first, middle, and last two letters of a color word formed color patches. In other conditions, random letters were attached to these word parts. In a control condition, entire words formed the color patches. While no condition produced as much interference as the control condition, the first part of a color word interfered with color naming more than other word parts. The addition of unrelated letters had little or no effect on the interference produced by the first part of a word. The results are consistent with suggestions that word perception often involves the activation of an articulatory motor program which is initiated by the first part of the word.