Biomedical subjects

M Ingleton

Publications and source records attributed to M Ingleton.

3 recordsLinked to original sources

PubMed1993

Top-bottom and front-behind decisions on rotated objects.

Human adults decided whether a dot was nearer the top or bottom of rotated drawings of objects in a top-bottom task, and whether a dot was at the front of or behind rotated objects in a front-behind task. These two tasks were performed with the head upright and with the head tilted clockwise and counterclockwise in separate blocks of trials in order to dissociate retinal from environmental perceptual frames of reference. Response times increased approximately linearly with increasing departure from the orientation of the perceptual reference frame in both tasks and the magnitude of the effect was similar across tasks. In the head tilted conditions, the perceptual frame of reference was located midway between the environmental and retinal upright for both tasks.

Adolescent↗

PubMed1993

Orientation-invariant transfer of training in the identification of rotated natural objects.

The effects of stimulus orientation on naming were examined in two experiments in which subjects identified line drawings of natural objects following practice with the objects at the same or different orientations. Half the rotated objects were viewed in the orientation that matched the earlier presentations, and half were viewed at an orientation that mismatched the earlier presentations. Systematic effects of orientation on naming time were found during the early presentations. These effects were reduced during later presentations, and the size of this reduction did not depend on the orientation in which the object had been seen originally. The results are consistent with a dual-systems model of object identification in which initially large effects of disorientation are the result of a normalization process such as mental rotation, and in which attenuation of the effects is due to a shift from the normalization system to a feature/part-based system.

Adult↗

PubMed1991

Size invariance in curve tracing.

Subjects decided whether two dots were on the same curve or on different curves in patterns consisting of two curves and two dots in displays that had an exposure duration of 200 msec or that remained in view until the subjects' response. The overall size of the patterns was varied by a factor of two. Furthermore, across experiments, we manipulated the predictability of the size of the pattern on a particular trial. On half of the trials, the two dots were on the same curve; across these trials, the distance between the dots, along the curve, was manipulated systematically while the Euclidean distance between the dots was held constant. On the other half of the trials, the two dots were on different curves. The time to respond same increased monotonically as curve distance between the dots increased, suggesting that subjects mentally traced the curve in order to perform the task. The absolute size of the pattern had little or no effect on the response times, indicating that it was curve distance relative to the overall pattern size, rather than absolute distance, that controlled response times. Furthermore, expectancies about pattern size had essentially no effect on performance. Taken together, the results suggest that the rate of tracing is determined by various stimulus properties that covary with the overall size of the pattern on which tracing takes place, such as the distance between the traced curve and nearby distractor curves, or the curvature of the traced curve.

Adolescent↗