Multidimensional scaling of individual differences for an individual person with a hand-held calculator

An extension to the INDSCAL method of individual differences scaling was developed. The method derives measures of deviation from a “standard” observer, who is defined in terms of the INDSCAL subject weights. These weights are calculated for one individual person at a time. The method is implemented in a small hand-held calculator. The calculator is used for data acquisition, and it interacts with the user in a conversational manner through an alpha-numeric display. The present implementation of the method scales 84 judgments of pair similarity among seven objects and derives subject weights on two dimensions. The method can be extended to sets of up to 16 objects and up to six dimensions. The method is a feasible, cost-effective approach to classification of individuals on complex perceptual attributes within a single 1-h session.     

Dual on-line computers for research in cognitive psychophysiology

A laboratory configuration is described in which two compatible minicomputers are used to collect psychophyiological data and to generate a complex visual display. The two computers are part of independent systems used by different research groups for psychophysiological experimentation and cognitive reaction time research. With minimal additional requirements, however, it is possible to link the function of the two machines and greatly expand experimental possibilities. Two real-time applications are discussed, as well as other advantages of having compatible processors, such as simplified program development.     

Black suicide in the seventies: current trends.

In the most recent decade, the suicide rate among young blacks has risen to the point where it is nearly as high as that of their white peers. The data in this analysis reflect the striking contrast in age distribution in the suicide patterns of whites and blacks. Whereas white suicide increases in direct relation with advancing chronological age, suicide among blacks reaches its peak in the youthful years. Current statistics fail to reflect a "dramatic" or significant increase in the suicide rate of black women. Contrary to popular belief, black men in their twenties represent the most suicide-prone group. Young black males have been committing suicide at a steadily increasing rate during the past six years. Regionally, black suicide rates are highest in the North and West and lowest in the South. White suicide rates reflect a slightly different regional distribution. The highest rates occur in the West and the lowest in the North.     

The measurement of response force during a lever-press shock-escape procedure in rats

Three albino rats were given extensive exposure to an escape procedure in which shocks were scheduled to occur 30 sec apart. The amount of downward force exerted on the lever was continuously recorded and compared with traditional discrete measurement in which only responses above an arbitrary force threshold were recorded. Subjects typically remained in contact with the lever throughout the shock-free intertrial interval. Shock onset reliably occasioned a brief lurch from and return to the lever, which resulted in a lever-press escape response being recorded. Lever contact, which occupied an average of 90% of session time, showed great stability in force after a brief (e.g., 5-sec) period of instability after each shock terminated. In general, continuous measurement revealed considerably different results than discrete measurements of on-lever behavior. For example, continuous lever contact fluctuating near response threshold was often recorded as discrete responding, and sustained lever contact occurring below response threshold was omitted from discrete measurement.     

Book reviews

SANDERS, A. F. (Ed.). Attention and Performance III. Amsterdam: North Holland Publishing Company. 1970. Pp. viii + 442. (Price not known.)

CORCORAN, D. W. J. Pattern Recognition. Harmondsworth: Penguin Books Ltd. 1971. Pp. 223. £0.50.

SCHRIER, A. M. and STOLLNITZ, F. (Eds.) Behaviour of Nonhuman Primates Vol. III. New York: Academic Press Inc. 1971. £4.45.

KINTSCH, W. Learning, Memory, and Conceptual Processes. New York: Wiley and Sons. 1970. Pp. 498. £4.40.

MORTON, J. (Ed.) Biological and Social Factors in Psycholinguistics. London: Logos Press. 1971. Pp. 215. £3.50.

RITCHIE RUSSELL, W. The Traumatic Amnesius. London: Oxford University Press. Pp. 84. £2.00.

MILLER, N. E. Selected Papers. Chicago: Aldine Publishing. 1971. Pp. 874. £15.00.

SUTHERLAND, N. S. AND MACKINTOSH, N. J. Mechanisms of Animal Discrimination Learning. New York: Academic Press. 1971. Pp. 559. $18.50.

FURCHTGOTT, E. (Ed.). Pharmacological and Biophysical Agents and Behavior. New York: Academic Press. 1971. Pp. xii+402. $14.50.

EYSENCK, H. J., ARNOLD, W. AND MEILI,R. (Eds). Encyclopedia of Psychology. Volume I. London: Search Press. 1972. Pp. 396. £8.00.     

Students' perceptions and reported use of their memories after a memory-improvement course

23 college students who had taken a memory-improvement course completed a questionnaire at three different times: the beginning of the course, the end of the course, and two months after the end of the course. The questionnaire assessed the students' perceptions of their memory abilities, e.g., how good their memories were and how confident they were in their memories and knowledge about their memories, and their reported use of the memory techniques; it did not assess actual memory performance or ability. The students' responses to the questionnaire were compared with those of 23 control students who completed the questionnaire at the same three times. The memory students reported more positive changes in how they perceived their memory abilities and knowledge, and these reported changes in perceptions were still evident two months later. The students also reported that they were still using their memory techniques two months later.