Effect of monochromatic rearing on the control of responding by wavelength

The wavelength of a discriminative stimulus exerted no control over the behavior of ducklings raised in a monochromatic environment. Stimulus control was established, however, when responding was reinforced in the presence of one wavelength and not in the presence of another.

Behavior in a novel situation as influenced by the immediately preceding environment

Behavior in a novel situation, which basically represented an increase in complexity for some Ss and a decrease in complexity for others, was sampled by the use of an exhaustive list of response categories at 5-sec intervals for 24 min. Wide behavioral differences are described. In addition, the feasibility of the time-sampling technique for the study of animal behavior is further demonstrated, and its more general use is advocated.

Some parameters affecting the distributional properties of operant-level running in rats

Six adult female albino rats were subjected to operations known to increase the frequency of wheel-running. Operations included limited access to wheel, food deprivation, and protracted maintenance on a 24-hr feeding schedule. A distributional analysis of response duration, burst duration, and inter-burst interval showed that the increased frequency in all cases arose mainly from a shortening of the interval between successive bursts. Only short-term food deprivation produced any notable increase in burst length, and even here changes in both speed of the individual responses and in number of responses per burst were slight compared to changes in inter-burst interval.

The operant control of vocalization in the dog

Control over the vocal responses of three dogs was established using operant-conditioning procedures. Several points of interest were observed in the data. First, fixed-ratio schedules of reinforcement generated a vocal response topography which was similar in detail to that of a "motor" bar-nosing response. Second, vocal responding was brought under the control of external visual stimuli as a result of differential reinforcement. Third, good stimulus control was maintained on a multiple schedule containing a vocal-response component and a bar-response component. Fourth, the stimulus control on the multiple schedule transferred with minimal disruption to a chain schedule requiring a sequence of 10 bar responses followed by 10 vocal responses. Fifth, because vocal and bar responses are not mutually exclusive, concurrent responding tended to develop on the chain schedule. These results were discussed with reference to the advisability of applying the terms operant and respondent to unconditioned behavior, and, particularly, to unconditioned verbal behavior.

Motor responses of moths to low-intensity x-ray exposure

A brief burst of x-rays elicited flight activity in moths placed in a darkened x-ray exposure room. Wing-beat activity was recorded as an index of this behavior. Wing-beat activity could be initiated in resting moths or amplitude augmented in active moths by x-ray dose rates of 0.01 to 1.5 roentgens per second, with a latency of less than 1 second after onset of exposure.