A device for the easy administration of volatile anesthetics to rats undergoing stereotaxic surgery

Conventional procedures do not provide a practical method for the administration of volatile anesthetics such as halothane to rats while they are undergoing stereotaxic surgery. This paper describes a device which meets this need and which is easy and inexpensive to construct. A two-piece cylinder cut from the mouth of a polyethylene bottle forms a closed system around the muzzle of a rat and does not interfere with the stereotaxic apparatus or with the operation itself. The cylinder is attached to any standard device for the dispension of volatile anesthetics. The immediate advantage is that behavioral assesaments can be made relatively soon after surgery.     

Error patterns in a chord keyboard response task

Errors in a serial choice-reaction time experiment employing two-finger chord responses to alphabetic stimuli are shown to be distributed in a significantly non-random fashion. Two factors are postulated which are relevant to prediction of the error response. These are the presence or absence of a common finger, and the difference in finger separation, between the actual and the required response. It is suggested that the chord response is coded in terms of a pattern (the distance between the two response components). Responses which mirror the correct response about the centre of the hand are also shown to be significantly more frequent.     

Sleep and overextinction of the GSR component of the orienting response

Overextinction of the GSR component of the orienting response was examined in a sample of 68 socially disturbed adolescents. Continued stimulus repetition beyond the point of habituation resulted in GSR return after 50–60 stimulus presentations. However, division of Ss into sleep and non-sleep groups using behavioral and self-report criteria, failed to support Sokolov’s (1963) notion that overextinction is accompanied by drowsiness. A possible explanation of these results is discussed.     

Taste sensitivity in infrahuman species: Use of a genetic model to test the validity of alternative measures

In a genetic analysis of PTC taste sensitivity of mice, Ss were presented tap water and a PTC solution in a two-choice situation. A preference index was used as a measure of taste sensitivity, assuming that ability to taste would lead to avoidance, i.e., negative preference. This assumption, however, lead to the rejection of seven Ss who preferred the test solution. Due to the undesirability of deleting Ss, the data were reanalyzed, using an alternative index of taste sensitivity that required no assumption concerning the hedonic quality of the test solution. Information regarding the inheritance of taste sensitivity to PTC provided the validating criterion for this measure.     

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.     

Looking time: Experimenter and instruction effects

A 2 by 3 factorial design was used to investigate the effects of the instructions and the presence of E on looking time. Two hundred thirty-nine college students viewed 30 colored stimuli of landscapes, single objects, and arrays of objects under three different sets of instructions, with E either present or absent while S viewed the stimuli. The results demonstrated that E’s presence depressed the time spent looking at the stimuli Evidence was also found suggesting that ambiguity in the typical instructions given Ss in looking-time experiments may result in artifactually long looking times. It was concluded that a more appropriate situation to investigate looking time would (1) utilize sham GSR instructions to reduce S’s uncertainty concerning the experiment’s purpose, and (2) arrange for E’s absence while S is viewing the stimuli