, Volume 45, Issue 5, pp 391-394

Visual acceleration detection: Effect of sign and motion orientation


Thresholds for the detection of constant acceleration and deceleration of a discrete object moving along horizontal and vertical axes were studied. A staircase methodology was used to determine thresholds for three average velocities (0.7, 1.2, and 1.7 deg/sec). Thresholds, expressed as the proportion of velocity change, did not differ significantly among the average velocities; thus, a consistent Weber-like fraction is suggested by the data. Furthermore, there was an interaction between the axis of motion (horizontal or vertical) and the sign of the velocity change (acceleration or deceleration): accelerations were easier to detect along the vertical axis, decelerations along the horizontal axis.

This article is based on Jack B. Calderone’s honors’ thesis. Portions of this paper were presented at the Fourth International Conference on Event Perception and Action, Trieste, Italy, August 1987, and at the 68th Convention of the Western Psychological Association, Burlingame, CA, April 1988.