Control of responding by the elements of a compound discriminative stimulus and by the elements as individual discriminative stimuli

In the first of two studies, the responding of four albino rats was differentially reinforced in the presence of noise and light together and then tested in the presence of the noise and the light separately during extinction. The light exercised substantially more control of responding than did the noise. In the second study the responding of a similar group of four rats was differentially reinforced in the presence of the noise and the light separately. Control of responding by the light developed more rapidly than control by the noise. Results suggest that levels of control by stimuli after differential reinforcement with respect to the stimuli together can be predicted by the rates of development of control during differential reinforcement with respect to the stimuli separately.     

CHEMICAL TRANSFER OF ALTERNATION TRAINING IN THE SKINNER BOX

F jerdingstad , E. J. Chemical transfer of alternation training in the Skinner box. Scand. J. Psychol ., 1969, 10 , 220–224.—In six individual experiments one group of recipient mice was injected with brain extract from rat donors trained to alternate between bars in a Skinner box; another group was injected with extract from donors reinforced for pressing either bar irrespective of choice. During testing the recipients of 'alternation extract' showed a significantly higher tendency to alternate.     

A STUDY OF MOTION PREFERENCES

M ashhour , M. A study of motion preferences. Scand. J. Psychol ., 1969, 10 , 299–105. — Human motion preferences as a function of velocity were investigated by the method of paired comparisons under 3 conditions of motion track length. It was found that, ( a ) for all the conditions and irrespective of sex, preference was a unimodal asymmetric function of velocity, the modal value being about 50–80 min of arc/sec, ( b ) motion track length affected the proportions of preferential judgments without affecting the asymmetry and unimodality features of the functions, ( c ) preferences were independent of velocity ratios. The relationship between preference and attention are discussed.