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Biomedical subjects

R Becklen

Publications and source records attributed to R Becklen.

6 recordsLinked to original sources
PubMed1985

Vector analysis and process combination in motion perception.

Experiments are reported supporting an altered explanation of the vector analysis that occurs in certain motion displays discovered by Johansson (1950). What seemed the result of a perceptual vector analysis is ascribed to the outcome of two different, independent stimulus conditions to which such displays can give rise because of external vector analysis. The different stimulus conditions are configurational change on the one hand and one of the subject-relative stimulus conditions on the other. In two of Johansson's displays, conditions for configurational change were altered by adding stationary reference points in the surround of the displays. Veridical perception of the displays resulted in a majority of instances. We also found that the different motions that result from configurational change and from subject-relative stimulation may combine to form unitary perceived motions and that this happens quite frequently under some conditions.

Humans↗
PubMed1984

A limitation of position constancy.

When the eyes track a moving object, the image of a stationary target shifts on the retina colinearly with the eye movement. A compensation process called position constancy prevents this image shift from causing perceived target motion commensurate with the image shift. The target either appears stationary or seems to move in the direction opposite to the eye movement, but much less than the image shift would warrant. Our work is concerned with the question of whether position constancy operates when the image shift and the eye movement are not colinear. That can occur when, during the eye movement, the target undergoes a motion of its own. Evidence is reported that position constancy fails to operate when the direction of the target motion forms an angle with the direction of the eye movement.

Adult↗