A comparison of operant licking and lever pressing in the rat

Two groups of rats were trained on a signaled, free-operant, avoidance procedure to lick or to lever press in order to avoid shock while water-deprived or satiated and, in the case of licking, while ingesting deionized water, isotonic saline, or 10% sucrose. The most effective avoidance licking occurred while the rats were water-deprived and ingesting 10% sucrose. Water deprivation level had no effect on lever pressing for shock avoidance. Two other groups of rats were operantly conditioned to lick or to lever press for food pellets while waterdeprived or satiated and, in the case of licking, while ingesting deionized water or 10% sucrose. The most effective licking for food reinforcement occurred while the rats were water-deprived and ingesting 10% sucrose. Water deprivation level had no effect on lever pressing for food reinforcement. The data indicated that effective operant licking must be supported by factors related to water regulation and taste palatability.     

Vicious-circle behavior in the Y maze

Laboratory rats were given escape training in both arms of a Y maze followed by extinction in one of four conditions: regular (no shock), punished (both arms containing a shock mid-segment), choice, or forced (one arm containing a shock mid-segment, one arm shock free). Subjects in the punished and forced conditions required more extinction trials than those in the regular extinction condition. The choice condition was intermediate and not significantly different from the others. Choice subjects avoided the shock by choosing the safe alley early and consistently during extinction, but some continued to run for many trials without further punishment. It was suggested that the number of punished trials early in extinction is related to persistence of running, and the results were discussed in relation to the Mowrer-Brown and the discrimination hypotheses.     

Reinforcing fluency in stutterers: An experimental study

Subject-specific periods of fluent reading responses of three adult stutterers were positively reinforced with the presentation of a dime. Subjects were run individually through a sequence of two base rate, two experimental, and two extinction sessions, each session lasting 45 min. Periods of fluent reading responses increased during the experimental condition for each of the three subjects. When the reinforcer was withdrawn during the extinction condition, the frequency of fluent periods showed a decrease. Concomitantly, disfluencies decreased during the experimental condition and they increased during the extinction condition. The clinical implications of fluency manipulation as against disfluency manipulation are discussed.     

Numerical taxonomy of aphasia

Two hundred consecutively seen aphasics, 142 of them with infarcts, were examined by tests of fluency, comprehension, repetition, naming, and information content. The language scores were subjected to a minimum variance clustering algorithm separately for the total and for the infarct groups. The latter generated 10 clusters on a dendrogram. Attribute analysis of each cluster provided a clinically meaningful profile of language performance for these groups. The degree of correlation of most computer generated clusters with clinically recognized groups was high, and the homogeneity of some of the clusters is striking. An exception appears to be “conduction aphasia,” which is bimodally distributed. One of these clusters, with high fluency and low comprehension scores, was renamed “afferent conduction” aphasia, and the other, with lower fluency and higher comprehension, was renamed “efferent conduction” aphasia. The Principal Components Analysis was used to evaluate the discriminatory value of language characteristics, and the Nearest Neighbor Network Analysis was used to evaluate the significance of clustering. The dendrogram for all aphasics showed a less specific and less homogenous six clusters.     

Children's attention to stimulus components with variation in relative salience of components and degree of stimulus integration

A total of 400 children at ages 5, 9, and 12 years were given a component selection task with stimuli differing in color and shape. Relative salience of these two stimulus components was manipulated across subjects in two ways: the standard shapes and colors from previous studies were compared with standard shapes in fluorescent colors, and the latter materials were compared with nonsense shapes in fluorescent colors. While fluorescence of color had little effect, the replacement of standard shapes with nonsense figures caused attention to be redirected from shape to color as the primary cue for learning. This effect was more pronounced at age 9 than at age 5. Apparently there is a greater tendency for older than for younger children to withdraw attention from a normally dominant component such as shape, when it is advantageous to adopt another feature such as color as the primary functional cue. An additional variable was integration of components (color within shape vs color as background for shape). Integration produced generally greater attention to color but did not affect the general pattern of salience effects.     

Rapid educational rehabilitation for prison inmates

One of the major goals of prisons has been the educational rehabilitation of inmates. Studies have shown that predelinquents as well as delinquents could be motivated to achieve in academic areas through the use of an incentive system. The present study attempted to extend the behavioral yield of such a system with prison inmates. The academic performance of two inmates in math and English were compared when two levels of incentives were made contingent on that performance. The results showed that the two inmates passed academic tests as much as nine times faster under an enriched schedule of incentives than under a standard one. This increase in rate of performance was translated into actual academic achievement as one of the inmates passed 9th through 12th grade algebra in only 14 days. A standardized test confirmed this academic advancement for both inmates. These high rates of performance and academic achievement are even more dramatic in view of the fact that five months prior to this procedure, both inmates had been tested as being below average in intelligence.