The semiautomatic Wisconsin general test apparatus

A semiautomatic version of the Wisconsin General Test Apparatus is described along with circuitry. Comparison data are provided for the semiautomatic and manual WGTA obtained under comparable procedures and conditions. Response latencies are given for go/no-go object discrimination problems and subsequent retention tests.     

Book reviews

Encyclopaedia of Linguistics, Information and Control. Edited by A. R. Meetham with the assistance of R. A. Hudson. Oxford: Pergamon Press. 1969. Pp. xiv + 718. 300s.

The Biological Basis of Personality. By H. J. Eysenck. Springfield: Thomas. 1968. Pp. xv + 399. $18.50.

Scientific Basis of Dvug Dependence. Biological Council Symposium. Edited by H. Steinberg. London: Churchill. 1969. Pp. 429. 100s.

Minnesota Symposia on Child Psychology, Vol. 2. Edited by John P. Hill. Minneapolis: University of Minnesota Press. 1969. Pp. viii + 172.

Memory and Attention: an introduction to human information processes. By Donald A. Norman. Chichester, Sussex: John Wiley. 1969. Pp. ix + 201. 84s. (cloth); 44s. (paper). Verbal Learning and Memory: selected readings. By Leo Postman and Geoffrey Keppel. Harmondsworth: Penguin Books. 1969. Pp. 501. 12s.

Handbuch der Kinderheilkunde. Edited by H. Opitz and F. Schmidt. Rand VIII/I: Neurologie-Psychologic-Psychiatrie. Redigiert von F. Schmidt und H. Asperger. Berlin: Springer Verlag. Pp. 1060. Price DM385, S96.25.

Digital Computing. By R. S. Lehman and D. E. Bailey. London: John Wiley & Sons Ltd. 1969. Pp. xxiv + 303. 79s.

Real-Time Computers. By W. R. Uttal. New York: Harper & Row. 1968. Pp. xiv + 338. 93s.     

The effects of amount of training per reversal on successive reversals of a color discrimination

Three groups of pigeons were trained on a red-green discrimination in which the stimuli were alternately presented in a multiple schedule of reinforcement. The discrimination was reversed 24 times. Groups were given 1, 2, or 4 hr of training on each discrimination. Increasing the length of training had two principal effects on reversal performance: it increased the rate of extinction of responding to one of the stimuli and increased the rate of reacquisition of responding to the other. The latter effect involved both an increase in reacquisition of responding to a positive stimulus within reversals and an increase in recovery of responding to the previous negative stimulus between reversals. Improvements in performance of each group over the series of reversals were qualitatively similar to the two effects of length of training on each discrimination, and were analogous to effects obtained in other studies involving overtraining and successive reversals of simultaneous discriminations.