UCS intensity and performance in eyelid conditioning

Studies of the effects of UCS intensity on performance in human eyelid conditioning are reviewed, particularly with respect to a recent claim that this variable determines the proportion of Ss who condition and not the performance level of individual Ss. The evidence reviewed clearly indicates that UCS intensity does affect the level of performance in Ss who condition. The function involved appears to be negatively accelerated and to approach an asymptote within a relatively small range of intensity values. These effects of UCS intensity are interpreted as reflecting both motivational and associative factors. (28 ref.)