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.     

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.     

Stimulus correlates of tachistoscopic discrimination-recognition performance: Compactness,jaggedness, and areal asymmetry

The utility of three physical dimensions (compactness, jaggedness, and areal asymmetry) of four-sided random forms on discrimination-recognition performance was examined. Six experimental conditions were defined by constructing discrimination-recognition problems wherein forms were paired on the basis of a high or low value on each of the three physical dimensions. Twenty-six Ss were randomly assigned to each experimental condition and were tested on five problems, four times at each of five single form duration times. Each problem presentation consisted of selecting which of two forms had been previously exposed at the selected duration. Analyses of the number of correct responses indicated support for the existence of a selective attention process and the utility of the compactness physical dimension.     

Academic Careers of Gifted Women

As part of a larger study concerning academically gifted college women, gifted freshman women who graduated (723) were compared with those who did not graduate (526) on certain academic variables. Graduates took an average of 12.6 quarters to complete their degrees. Average length of attendance before departure for Nongraduates was 5.8 quarters. Graduation with honors was achieved by 51.9 per cent of the Graduates. Graduates and Nongraduates differed significantly in GPA (3.06 to 2.50), contact with the Counseling Bureau (43.6 to 30.9 per cent), and in major fields of study. More Graduates had Liberal Arts (CLA) “social science,” CLA “interdepartmental and double,” Education, and Home Economics majors. More Nongraduates had CLA “English, linguistics, and languages,” CLA “natural science and mathematics,” and Business Administration majors. These results are discussed in relation to findings of the larger study concerning personality characteristics and vocational interests of gifted women, and a follow-up study of the Nongraduates.