The effects of response contingent reinforcement and response contingent punishment upon the frequency of stuttered verbal behavior

Twelve adult subjects, 4 in each experimental condition, were exposed to 2 punishment contingencies and 1 punishment and reinforcement combined contingency, under a procedure of stimulus control. Results indicated all 3 conditions to be equally effective in the reduction of stuttering frequency. Spontaneous recovery during stimulus control segments was not observed following any of the three experimental contingencies. Implications for research and therapy are discussed.     

Mechanisms of forgetting in short-term memory

This paper introduces a technique applicable to the question: Does information in short-term memory disappear with time? The technique appears to eliminate Ss' rehearsal in the retention interval without introducing potentially interfering material. In the experiment, Ss read aloud three words, then engaged in a difficult auditory signal detection task intended to keep them from rehearsing for 15 sec, and then attempted to recall the three words. The results provide no support for the principle of loss with time as an explanation of forgetting in short-term memory.     

A study of cardiac conditioning in man

Conditioning procedures for EEG, ECG, and PGR responses were evaluated in 23 male and female human Ss. A 5 sec. 310 cps tone served as the CS+; a 130 cps 5 sec. tone served as the CS?. The US was a 10 msec. 6 ma shock to the finger. After orienting responses had extinguished, conditioning trials were initiated and continued until the S showed conditional responses on 5 consecutive occasions. PGR and ECG results were in accord with the findings of other authors working on animals. The significance of the responses studied was discussed in terms of data recorded by other investigators.     

Experience-Expectant Plasticity in the Mushroom Bodies of the Honeybee

Worker honeybees (Apis mellifera) were reared in social isolation in complete darkness to assess the effects of experience on growth of the neuropil of the mushroom bodies (MBs) during adult life. Comparison of the volume of the MBs of 1-day-old and 7-day-old bees showed that a significant increase in volume in the MB neuropil occurred during the first week of life in bees reared under these highly deprived conditions. All regions of the MB neuropil experienced a significant increase in volume with the exception of the basal ring. Measurement of titers of juvenile hormone (JH) in a subset of bees indicated that, as in previous studies, these rearing conditions induced in some bees the endocrine state of high JH associated with foraging, but there was no correlation between JH titer and volume of MB neuropil. Treatment of another subset of dark-reared bees with the JH analog, methoprene, also had no effect of the growth of the MB neuropil. These results demonstrate that there is a phase of MB neuropil growth early in the adult life of bees that occurs independent of light or any form of social interaction. Together with previous findings showing that an increase in MB neuropil volume begins around the time that orientation flights occur and then continues throughout the phase of life devoted to foraging, these results suggest that growth of the MB neuropil in adult bees may have both experience-expectant and experience-dependent components.     

Characteristics of residential care for adolescent offenders: A comparison of assumptions and practices in two models

Staff assumptions and program practices in two models of residential care for male adolescent offenders were compared. Group care settings had from 6 to 15 youths in residence and used peer-mediated treatments. Treatment Foster Care settings had one youngster placed in each home and treatments were adult-mediated. Results showed that group care and Treatment Foster Care program models differed on staff assumptions about therapeutic mechanisms of change, and different patterns of daily program practices were found.