Biomedical subjects

M L Manning

Publications and source records attributed to M L Manning.

21 records · Page 2Linked to original sources

PubMed1987

Individual differences in responses of untrained observers to stroboscopic apparent motion.

Two large groups of inexperienced subjects (n = 208 and n = 50) and a small group of experienced subjects (n = 5) were tested using time-till-breakdown as a measure of long-range apparent motion across a range of temporal frequencies. One group of inexperienced subjects was retested after one week and demonstrated quite stable patterns of response. Large intersubject variability was observed in terms of the amount of motion seen, with most inexperienced subjects reporting very little apparent motion. A raster display produced a peak frequency 1 Hz higher than a standard tachistoscope display. The role of experience was also examined with a small group of inexperienced subjects (n = 8) tested once daily over five consecutive days. There was high intersubject variability and intrasubject consistency, demonstrating little influence of learning and experience. The results are discussed in terms of current ideas on the breakdown effect.

Humans↗

PubMed1986

Evoked potentials to dynamic random dot stimuli with varying dot density ratios of disparity to background.

A systematic study was made of visual evoked responses to dynamic random dot stimuli containing controllable, monocularly visible contrast cues. Ratios of dot densities for the centrally presented, disparate figure and the background were varied in steps of 1/8 maximum density between 0/8 and 8/8. The figure was either a square or an equivalent area of nebulous shape. A 30-arc min disparity was compared with binocular nondisparate and monocular conditions. Evoked responses (scalp sites 02, 01, T6, T5) were averaged for each of 24 disparity-contrast-shape conditions. At all contrast levels, response amplitudes and latency over the left hemisphere was significantly greater than over the right hemisphere. For 30 arc min disparity, amplitudes in the 8/8 condition were significantly smaller than in conditions where stimulus/background contrast could afford monocular depth cues. Hemisphere amplitude differences diminished as contrast decreased. Factor analyses isolated two overlapping components in the response to disparate stimuli. The earlier, at 236 ms latency, may index the stereoscopic stimulus features. The later, at 295 ms, peaking at maximum contrast and present in all suprathreshold nondisparity conditions, may index contrast features of the stimulus. The results indicate the importance of controlling dot density ratios in electrophysiological studies of the stereoscopic response to random dot stimuli.

Adult↗

PubMed1983

Three myths concerning adolescence.

This paper examines relevant literature from the seventeenth century to the present regarding myths about adolescence. The findings do not support the contentions that adolescence is a time of rebellious, antisocial, and unacceptable behavior; the concept of adolescence has been present throughout history; and there is a generation gap between adolescents and their parents. Belief in these myths can distort perceptions, thus affecting the way professionals deal with adolescents. Debunking of these myths will allow professionals who work with adolescents to maintain objectivity by helping them distinguish clearly between fact and myths.

Adolescent↗