Task-related arousal of type A and type B persons: level of challenge and response specificity

To determine whether different levels of challenge had differential effects on the arousal levels of Type A and Type B persons, 30 Type A and 30 Type B male subjects worked on an intelligence test task (digits backwards recall) that was easy, moderately difficult, or extremely difficult. Arousal was measured in terms of systolic blood pressure, diastolic blood pressure, pulse rate, pulse volume, skin resistance, and subjective arousal. Results indicated that while working on the extremely difficult task, the Type A subjects evidenced reliably higher systolic blood pressure than did the Type B subjects (p = 0.1; difference = 7.52 mm of Hg) and that there were not reliable differences between the subjects in systolic blood pressure at other levels of challenge or on other measures of arousal.     

Participation,influence, and satisfaction in group decision making

The hypothesis that attitudinal effects of participation depend on individual differences in motivation was tested in a laboratory experiment with 56 three-man groups (leader and two members). Measures of the attractiveness of power and social acceptance were obtained prior to a group decision task, after which members described their perceived participation, influence, and satisfaction. Results showed that: (a) influence was more strongly related to satisfaction for members with strong, as opposed to weak, power motives; (b) for members with strong affiliation motives, participation was more strongly related to satisfaction than was influence. Relationships varied across satisfaction aspects. It was concluded that participation may be associated with favorable role attitudes through different motive-attainment mechanisms in the group decision-making process.     

Concurrent variation of response bias and sensitivity in an operant-psychophysical test

The yes-no signal detection procedure was applied to a single-response operant paradigm in which rats discriminated between a standard auditory intensity and attenuated comparison values. The payoff matrix was symmetrical (with reinforcing brain stimulation for correct detections and brief time-out for errors), but signal probability and intensity differences were varied to generate a family of isobias and isosensitivity functions. The d’ parameter remained fairly constant across a wide range of bias levels. Isobias functions deviated from a strict matching strategy as discrimination difficulty increased, although an orderly relation was maintained between signal probability value and the degree and direction of response bias.     

Auditory evoked brain responses: Intensity functions from bipolar human scalp recordings

Average evoked brain responses were computed from four simultaneous recordings during binaural tone stimulation at 10 intensity levels. Amplitudes and latencies were measured for the prominent components, and linear regression coefficients were computed. The results indicate that the sensitivity of the evoked response to stimulus intensity is dependent upon the selection of the appropriate measure. Linear amplitude functions were demonstrated. Additional research relating these responses to psychophysical measures is suggested.     

Detection of extraneous signals during sentence recognition

In two separate experiments, 40 Ss were presented with recorded sentences during each of which a click occurred. Ss had to depress a key as soon as they heard the click. RTs were f aster when the click was located at the major syntactic break of the sentence compared with RTs to clicks not at a break. This confirmed the hypothesis that processing load is a function of the surface structure of sentences, although the role of minor breaks was not clear. A second finding was that RTs were slower when the click was in the first rather than in the second half of the sentence. This can also be explained in terms of differential processing loads.