Auditory evoked potentials during selective listening to dichotic speech messages

The sensitivity of the scalp-recorded, auditory evoked potential to selective attention was examined while subjects monitored one of two dichotically presented speech passages for content. Evoked potentials were elicited to irrelevant probe stimuli (vowel sounds) embedded in both the right- and the leftear’s message. The amplitude of the evoked potential was larger to probe stimuli embedded in the attended message than to probe stimuli in the unattended message. Recall performance was unaffected by the presence of the probes. The results are interpreted as supporting the hypothesis that this evoked potential sensitivity reflects an initial “input selection” stage of attention.     

A comparison of the predictive validity of typical and maximal personality measures

Most personality tests are based on concepts assessing typical performance, and tests of this sort have not been generally successful in predicting criterion behaviors with useful levels of efficiency. Ability tests, which call for maximal performance, have been much more successful as predictors of criterion outcomes. Following a model derived from ability tests, predictors requiring separate typical and maximal self-reports of emotional expressivity were compared to measures of typical and maximal emotional expression in the laboratory. For angry expression, self-reports of maximal expressivity tended to outpredict self-reports of typical expressivity for both typical and maximal laboratory measures of angry expression. Although similar trends were observed for elation, the advantage of maximal self-report measures over typical self-report measures was negligible. Results were discussed in terms of both experimental and clinical implications.     

Monaural right-ear advantage in a target-identification task

Subjects were monaurally presented with consonant—vowel syllables to the right or left ear, with or without simultaneous noise to the other ear. The subject's task on each trial was to indicate whether or not the item presented was the target item /ba/. A right-ear advantage in reaction time was obtained: 14 msec for target items, 6 msec for nontarget items. The size of this effect was comparable in the presence vs. absence of competing noise. No consistent individual differences were found in the size of the right-ear advantage for this task, although such differences were obtained in a dichotic-perception pretest.It is argued that data of this type do not permit inferences about the use of particular ear/hemisphere neural pathways.     

Dichotic competition of simultaneous tone bursts of different frequency: IV. Correlation with dichotic competition of speech signals

Presentation of dichotic chords to thirty subjects showed that 23% were right ear dominant, 40% were left ear dominant and 37% had no marked ear dominance. Presentation of dichotic consonant-vowel (CV) signals to the same subjects showed that 70% were right ear dominant and 30% were left ear dominant. Despite the fact that an ear dominance effect was present for both speech and non-speech sounds there was no significant correlation (either positive or negative) between an individual's performance on the two tasks. The performance of native speakers of tonal languages and of musicians was not significantly different from the experimental group of English speaking subjects. These results suggest that the two ear dominance effects are unrelated.     

An electronic visual stimulator

A group of circuits is described that produce various patterns on an oscilloscope screen that are useful in studying vision. These patterns are: a flashing bar, a drifting bar, a flashing grating, and a drifting grating. The circuits have controls for: contrast, velocity, width, position, and orientation with respect to the vertical. This article describes the principles of design and use of these circuit modules as a precise electronic visual stimulator.