Citation

Kaiser MK, Phatak AV. J. Exp. Psychol. Hum. Percept. Perform. 1993; 19(1): 194-202.

Affiliation

NASA Ames Research Center Moffett Field, California 94035-1000.

Erratum On

J Exp Psychol Hum Percept Perform 1993 Aug;19(4):743

Copyright

(Copyright © 1993, American Psychological Association)

DOI

unavailable

PMID

8440985

Abstract

Psychologists are intrigued with the idea that optical variables can specify not only the time until an object impacts an observer but also the severity of the impact. However, the mapping between the optical variables (tau and .tau) and the kinematic variables (velocity, acceleration) has been misstated, erroneously implying that there exist critical values of the optical variables used for locomotion and control. In this commentary, the mathematical relationship between the optical and kinematic variables is reexamined and the erroneous assumptions that have led to the proposal of critical values are show. Also examined are the empirical data on deceleration to approach (particularly from active control paradigms) to assess whether the proposed optical variables are likely candidates for control strategies. Finally, problems associated with numerical approximations to dynamic systems, particularly when analytic solutions exist, are discussed.

Language: en