The rabbit as a subject in behavioral research

Domestic rabbits were exposed to a wide variety of variables employed in behavioral research. It was found that: (1) Although food could be used as a reinforcer, the long periods of severe deprivation required to reduce body weight made its use impractical. (2) Water was an efficient reinforcer in that it maintained high rates of behavior after 22 hr of deprivation. (3) Except that rates of responding were higher, fixed-ratio and variable-interval schedules of reinforcement produced patterns of behavior similar to those demonstrated by rats and pigeons. (4) Although the duration of the post-reinforcement pause was a function of the duration of the interval under fixed-interval schedules, scalloping, as defined as a gradually increasing rate of responding between reinforcement, was not evident. (5) When provided with the means to both turn on and turn off intracranial stimulation, the duration of the stimulation and the frequency with which it was turned on and off was a function of the intensity of the stimulation. (6) Electric shock could suppress behavior and maintain escape responding, but would maintain avoidance responding only in a few subjects.     

Analyzing mothers' speech to young autistic children: A methodological study

The development of a technique for analyzing mothers' speech to young children is described. The need for such a measure arose from two linked studies of autistic children, one comparing them with developmental dysphasic children and the other evaluating the results of a home-based approach to treatment. A 17-category system was developed which could encompass almost all the types of speech shown by mothers of young autistic and normal children and which differentiated between the speech used by different mothers in a way that was meaningfully related to the child's level of language development. The categories proved to be easily applicable and to show good inter-observer reliability. Tape-recordings made during home observations were found to be the best source of speech samples. The problems of time sampling, length and nature of speech sample, and observer effects are discussed.We are most grateful to our colleagues Dr. Lionel Hersov and Mr. William Yule for many helpful suggestions in developing the measures and for their comments on an earlier draft of the paper. The study is supported by a grant from the (British) Department of Health and Social Security.     

Internal-external locus of control and response to influence attempts

It was hypothesized that subjects having external locus of control orientations (E's) would conform to both subtle and overt influence attempts, whereas internals (I's) would react against such attempts 144 undergraduate students (72 of each sex) rated a proposed grading procedure pre- and postinfluence Data were analyzed in a completely crossed and balanced 3-way factorial design, which included 3 levels of locus of control (I's, middles, and E's), 3 levels of influence (no, low, and high), and 2 levels of sex (male and female) Results showed that E's conformed to both levels of influence and I's reacted against high influence I's were not responsive to low influence     

The comprehension of rate-incremented aural coding

Stimulus and psychological measures of a battery of 36 rate-manipulated versions of an extended message indicate that optimization of the efficiency of aural coding beyond that previously reported can be accomplished by the simultaneous application of a combination of natural and artificial distortions of the durational characteristics of speech. Peak efficiency of listening was successfully pushed to 400 wpm (words per minutes) primarily by means of a selective reduction of speech pause time. Regression estimates predicting the influence of pause time, total duration, and talker rate upon judgments of speech rate and comprehension are presented and implications for listening strategies and speech apperception drawn.This research was supported by grant HD02417 from the National Institute of Child Health and Human Development.     

Changes of pupil size and rehearsal strategies in a short-term memory task

Twelve subjects learned lists consisting of 3 groups of 4 items each drawn from vocabularies of digits, colour names or boys' names. There were two conditions of recall, total or partial, and two retention intervals, 3 and 7 sec. A view of the function of rehearsal suggests that rehearsal for total recall should be more intense than for partial recall, but only with a brief retention interval. Measurements of pupillary diameter confirm this prediction. Conditions under which pupillary measurements can serve to test theories of psychological processes are discussed.