Biomedical subjects

R A Finke

Publications and source records attributed to R A Finke.

27 records · Page 2Linked to original sources

PubMed1981

Methodological considerations in experiments on imagery acuity.

We examine the possible reasons why the results of our recent study on imagery acuity differed from those of an attempted replication by Intons-Peterson and White. Comparison of the two studies suggests that the differences in results are likely to be due to differences in procedures for giving imagery instructions and measuring the fields of resolution, and not to the presence or absence of experimenter bias. Accordingly, we discuss the importance of using skilled and practiced experimenters when conducting imagery acuity experiments. In addition, we address issues raised by Banks concerning the identification of particular levels of functional equivalence in imagery and perception.

Discrimination Learning↗

PubMed1980

Mental imagery acuity in the peripheral visual field.

Subjects made judgements of resolution on two small dots that they either imagined or acutally observed at horizontal and vertical positions away from the point of eye fixation. As the distance between these two dots increased, the size of fields of resolution in imagery increased, in proportion to increases in the size of fields of resolution in perception. For vivid imagers, fields of resolution in imagery were the same size as those in perception, whereas for nonvivid imagers, fields of resolution in imagery were smaller than those in perception. In addition, fields of resolution in imagery and perception were virtually identical in shape, exhibiting similar horizontal eccentricity and vertical asymmetry. Fields within which attention can be distributed in imagery were also measured by having subjects make judgements of resolution on pairs of dot patterns imagined simultaneously on opposite sides of the point of eye fixation. These fields were smaller than fields of resolution for images of single dot patterns and were circular, as opposed to elliptical. These results suggest that peripheral acuity in visual imagery is limited by the same types of neural constraints that limit peripheral acuity in visual perception.

Distance Perception↗

PubMed1980

Emergent two-dimensional patterns in images rotated in depth.

Once a person has observed a three-dimensional scene, how accurately can he or she then imagine the appearance of that scene from different viewing angles? In a series of experiments addressed to this question, subjects formed mental images of a set of objects hanging in a clear cylinder and mentally rotated their images as they physically rotated the cylinder by various amounts. They were asked to perform four tasks, each demanding the ability to "see" the two-dimensional patterns that should emerge in their images if the images depicted the new perspective view accurately--(a) Subjects described the two-dimensional geometric shape that the imagined objects formed in an image rotated 90 degrees; (b) they "scanned" horizontally from one imagined object to another in a rotated image; (c) they physically rotated the empty cylinder together with their image until two of the imagined objects were vertically aligned; and (d) they adjusted a marker to line up with a single object in a rotated image. The experimental results converged to suggest that subjects' images accurately displayed the two-dimensional patterns emerging from a rotation in depth. However, the amount by which they rotated their image differed systematically from the amount specified by the experimenter. Results are discussed in the context of a model of the mental representation of physical space that incorporates two types of structures, one representing the three-dimensional layout of a scene, and the other representing the two-dimensional perspective view of the scene from a given vantage point.

Adult↗

PubMed1980