Effects of availability of microcomputers on student and faculty research

The effect of the widespread availability of microcomputers on research is discussed. Student projects in a course in computer applications in psychology improved markedly, and faculty who had previously not believed that there was great value in using computers discovered innovative ways of facilitating their research.     

Patterns of cardiovascular responses to stress as a function of race and parental hypertension in men

This study investigated cardiovascular responses to two stressors known to elicit either beta-adrenergic (mental arithmetic) or alpha-adrenergic (forehead cold pressor) reactivity in Black and White men. Participants in each group were selected for presence or absence of parental hypertension. Based on previous research, Blacks were expected to show smaller cardiovascular responses to the beta-adrenergic mental arithmetic task and greater responses to the alpha-adrenergic cold pressor relative to the Whites. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, forearm blood flow, and forearm vascular resistance were assessed during a resting baseline, a prestress period, and during and after each experimental procedure. Unlike previous findings, no significant racial differences in cardiovascular responses were found during either task. However, Black participants had significantly higher SBP and DBP levels throughout the cold pressor periods. Parental history did not significantly influence cardiovascular responses in either group. The results are discussed in relation to previous research on racial differences in stress reactivity and their implications for future research.     

Effects of stimulus and contextual information on the lexical decision process

Two experiments were conducted to investigate context effects on the lexical decision process. In both experiments, observers classified letter strings as words or nonwords following the presentation of context in the form of an incomplete sentence. In Experiment 1, the predictability of congruous word stimuli and their frequency of occurrence in printed English were varied. These two factors had independent and additive effects on decision latencies. Stimulus quality, word frequency, and semantic congruity (i.e., congruous vs. incongruous) between the context and the stimulus were varied in Experiment 2. The effects of semantic congruity and word frequency on decision latencies combined additively, as did the effects of semantic congruity and stimulus quality. Two complementary mechanisms were proposed within the framework of a modified version of Becker’s verification model to account for the differential effects of single-word and sentence context priming on the lexical decision process.     

The patterns of silence: Performance structures in sentence production

The pauses produced by speakers while reading familiar material were used to obtain hierarchical sentence structures. Identical structures were obtained from parsing, indicating that the performance structures of sentences are not task specific. The linguistic surface structure of a sentence is a good predictor of the pause durations. However, speakers also revealed a tendency to place pauses between segments of equal length. A simple cyclical model combining, for each pause location, an index of linguistic complexity and a measure of the distance to the midpoint of the segment, accounts for 72% of the pause time variance as opposed to 56% for the linguistic index alone. The generality of the model is shown by its good prediction of the pause durations obtained in unrelated studies in English and American Sign Language.     

Cerebral asymmetry for American Sign Language: The effects of moving stimuli

Previous studies of cerebral asymmetry for the perception of American Sign Language (ASL) have used only static representations of signs; in this study we present moving signs. Congenitally deaf, native ASL signers identified moving signs, static representations of signs, and English words. The stimuli were presented rapidly by motion picture to each visual hemifield. Normally hearing English speakers also identified the English words. Consistent with previous findings, both the deaf and the hearing subjects showed a left-hemisphere advantage to the English words; likewise, the deaf subjects showed a right hemisphere advantage to the statically presented signs. With the moving signs, the deaf showed no lateral asymmetry. The shift from right dominance to a more balanced hemispheric involvement with the change from static to moving signs is consistent with Kimura's position that the left hemisphere predominates in the analysis of skilled motor sequencing (Kimura 1976). The results also indicate that ASL may be more bilaterally represented than is English and that the spatial component of language stimuli can greatly influence lateral asymmetries.     

Spatial visualization and sex differences in quantitative ability

The hypothesis that sex differences in spatial visualization ability might account for sex differences in mathematical ability was supported for a group of 183 male and 81 female college students. With spatial visualization statistically controlled, no significant sex differences in Quantitative Scholastic Aptitude Test (QSAT) scores was found; including sex as a predictor variable increased the variance explained by less than 1%. Although the slope of the regression of mathematics on spatial visualization did not differ as a function of sex, males were somewhat more predictable than females. As the OSAT of both males and females high on spatial visualization was more predictable than the QSAT of those scoring less well, it appears that the sex difference in predictability is due to males having higher spatial ability than females.     

Gradients of auditory generalization for blind, retarded children

Severely retarded, blind children were conditioned to respond differentially to two intensities of a pure tone. Gradients of auditory generalization were obtained that were reliable and similar to those for normal adults, but often asymmetric and non-monotonic.