Light reinforcement in the rat: The effects of continuous and discontinuous periods of apparatus familiarization

The effects of continuous and discontinuous periods of apparatus familiarization on light reinforcement in rats were examined. A previous finding that the light reinforcement effect is greater with longer pretest periods in the dark box was confirmed by comparing 270 min and 30 min periods in the box prior to testing 24 h later. A discontinuous period of 9 daily 30 min sessions, however, produced a bigger effect than the 270 min continuous period. It was concluded that the degree of familiarization with the apparatus is a more important factor than length of time per se in the dark in determining the effectiveness of light as a reinforcer.