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Biomedical subjects

B Wallace

Publications and source records attributed to B Wallace.

At least 91 records · Page 5Linked to original sources
PubMed1984

Hypnotic susceptibility and performance on various attention-specific cognitive tasks.

We conducted two experiments to investigate cognitive performance as related to level of hypnotic susceptibility. In Experiment 1 time-to-location of a target in a visual search task was assessed. For this task the letter Z was embedded either within straight-form or round-form letters. Results indicated that high-hypnotic-susceptibility subjects (highs) were significantly faster than low-susceptibility-subjects (lows) in locating the embedded letter. Experiment 2 investigated performance on single- and double-digit arithmetic (addition) problems as a function of hypnotic susceptibility level. Subjects were presented with arithmetic problems and were asked to complete them within a 60-s time period. Highs completed a significantly greater number of double-digit problems but not single-digit problems within this time frame than did lows. The results of the two experiments are explained in terms of the application of differing strategies or operations by highs and lows in the performance of cognitive tasks.

Attention↗
PubMed1984

The roles of target and eye motion in the production of the visual shift in prism adaptation.

Two experiments, with a total of 48 Ss, were performed to evaluate the possible determinants of the visual shift (VS) in prism adaptation. In Experiment 1 the effects of target movement and pursuit eye movements on resultant visual adaptation were investigated. Maximal VS was produced when both of these conditions were present. Experiment 2 was conducted to determine whether hypnotic anesthesia in and around the eyes and eye muscles reduces feedback from eye-position sensations and, consequently, the magnitude of the VS. This manipulation proved to be successful and virtually eliminated the production of VS. The results of the two experiments helped to identify two factors that contribute to the production of the VS: the presence of visual target movement during prism exposure and the accompanying eye movement which produces a change in the felt position of the eyes during target tracking.

Adaptation, Ocular↗
PubMed1982

Illusory changes in a sound source and outflow theory.

Two experiments, with a total of 220 Ss, were conducted to investigate the possibility of illusory movement of a sound source. In Experiment 1 intensity level (from 10 to 60 db SPL) and frequency of an auditory sound (from 1000 to 5000 Hz) were varied while the Ss head was stabilized with a head rest; in Experiment 2, intensity and frequency were also varied while the S's head was free to move. When head position was fixed, error signal variables such as intensity had no effect on the frequency of illusory direction changes of a sound source. However, when the head position was not fixed, increasing the intensity of the sound source significantly decreased the number of reported illusory direction changes. In addition, in both experiments, illusory changes of intensity were experienced by Ss, and increasing the intensity of the sound source also decreased this illusion. The results were interpreted in the context of an error signal and noise model of autokinetic effects, and the implications for the perception of auditory localization and movement of a sound source were discussed.

Auditory Perception↗