Effects of delay of instrumental reinforcement on human eyelid conditioning were investigated in 5 groups of 20 Ss each with delays of 0, 0.5, 1.0, 2.0, and 4.0 sec. between response and reinforcement. The reinforcement was illumination of a small lamp and operation of an electric counter, and S was told only that if he did the right thing the reinforcement would occur. Acquisition appeared to be maximal when the reinforcement was delayed from .5 to 2.0 sec. The function was a flat-topped inverted U with 0 delay and 4.0 sec. delays producing less conditioning. There was some indication of greater resistance to extinction in those Ss who received the 4.0sec. delay of reinforcement.

No abstract

It seems that visual acuity in combination with other variables may be a more important factor in the explanation of hemifield differences in perceptual accuracy than previously believed.

The present experiment was concerned, in part, with assessing the generality of findings obtained by Simon and Wood (1964) concerning the relative facilitation and inhibitory effects of prior PA stimulus familiarization on subsequent PA learning. Ss were 52 6th and 7th grade children. Results essentially supported those previously obtained with college students. The large attrition rate of Ss failing to reach familiarization list criterion suggests the fairly selected nature of the population of children to which these results can be generalized.