Frustration Effect in a Free Operant Situation for Albino Rats

Rats were trained to bar press for food reinforcement in a two-bar multiple fixed-ratio situation. After the animal had established asymptotic rates of time for transferring between bars and responding on each bar, responding on one bar led to no reinforcement or random intermittent (50%) reinforcement. Responding on a second bar was always reinforced. Under both schedules of reinforcement, rats decreased their time to transfer to the second bar and their time to respond on the second bar. All animals also displayed an initial disruption of transfer back to and responses on the first bar. For rats on the intermittent reinforcement schedule, the decreased response time on the reinforced bar was primarily found after nonreinforcement of response to the previous bar. Reinforcement schedules for response to the first bar did not differentially affect the above behavior.

Experimental Participation as a Source of Stimulation in Sensory and Perceptual Deprivation Studies of Stimulus-Seeking Behavior by Introverts and Extraverts

The hypothesis that the experiment itself provided a change in stimulation was tested under conditions of perceptual deprivation with and without delay of self-stimulation in a free operant situation. Also tested was the hypothesis that extraverts would differ from introverts in seeking more frequent changes in self-administered sound stimulation, rather than in seeking stimulation of greater duration. Parametric tests indicated no significant difference between delay and non-delay groups or between introverts and extraverts with respect to duration and frequency of sound stimulation. Non-parametric test, however, showed extraverts tended to seek significantly more changes of self-stimulation than introverts.

Overtraining Extinction Effect Using a Free-Operant Procedure

The effects of five levels of training (210, 490, 1470, 2450, 3430 reinforced responses) on extinction performance were investigated. A free-operant bar-press paradigm was employed. A continuous reinforcement schedule was used with .12 ml. of 64% sucrose. Number of bar-presses and duration of time to reach a 1-min. non-response criterion showed that resistance to extinction was an increasing function of the number of reinforcements during training. However, the amount of time required to reach a 5-min. criterion showed the opposite relationship. It was concluded that different criteria reflected different patterns of extinction behavior and that the overtraining extinction effect (decreased resistance to extinction following extended training) could be demonstrated in a free-operant situation if the appropriate criteria were selected.

Shaping and Increasing Verbalizations in an Autistic Child in Response to Visual-Color Stimulation

It was hypothesized that systematic visual-color consequences contingent upon verbalizations would be effective in augmenting the rate of sounds as well as shaping specific words and word approximations, in a six-yr.-old autistic child. It was found that verbalizations were augmented over a base rate in a free operant situation. However, in a prompt-response contingency food was significantly more powerful in shaping specific sounds. Reasons for the difference were discussed.