Early postural adjustments in cats during a reaching task reflect strategies to predict the forthcoming target location

Abstract

Many types of voluntary movement depend on appropriate postural adjustments. In most situations, such postural adjustments are influenced by learning and are therefore subject to prediction strategies developed through learning. To address how these prediction strategies affect early postural adjustments (EPAs) that occur several hundred milliseconds before movement, we trained two cats in a reaching task where the location of the target was predictable through learning. At the beginning of each trial, the cat stood still with each paw on a force plate for several hundred milliseconds. A target then appeared on either side of a horizontal touch panel, prompting the cat to lift a forepaw. A food reward followed upon holding the target with the forepaw. Target location was alternated every three rewarded trials: one SWITCH followed by two STAY trials. In both cats, EPAs prior to target onset in STAY trials were significantly dependent on the predetermined target location, indicating that they anticipated the target location as a part of their strategy. In SWITCH trials, EPAs aligned with the subsequent STAY trials in both switch directions for one cat, but only in one direction for the other, suggesting that they developed different strategies to handle target location switches.