Rhythmical body movement in sleep: a brief review and treatment study

Vigorous and damaging head-banging and head and body-rocking can occur in normal subjects of average intelligence before and during sleep. Reports of behavioural treatments for this are reviewed. Data from the present case and others suggest that waking plus efficient response prevention is sufficient to substantially reduce or eliminate the activity even when the treatment has been withdrawn for up to one year. The aetiology of the activity is not understood. However, this case suggests that head- and body-rolling, when long-established, need not enhance the quality of sleep since this was unimpaired on completion of treatment and was possibly even improved by the elimination of the movements. The present case also demonstrates that the behaviour can be treated successfully even when considerable environmental stresses occur.     

Unavoidable gridshock without scrambling circuitry from a faradic source of low-radio-frequency current

A high-voltage radio-frequency stimulator was used as a source of motivational footshock in studies of conditional suppression. The circuit of the stimulator is presented schematically, then discussed in terms of affect induced by, gross behavioral response to, and electrical characteristics of, the stimulus. Near daily use of the stimulator across 6 months of formal assessment revealed that nonscrambled presentations of footshock via a grid of aluminum bars invariably resulted in stimulation of rat Ss and generated highly efficient conditional suppression of operant responding. While the stimulator was primarily designed to permit unconfounded presentation of gridshock in a 2,450-MHz microwave field, its simplicity and reliability suggest application in other situations requiring motivational shock.     

Consistency between motor activity and perceived direction of rotation

Three experiments were conducted to test the proposition that engagement in motor activity in a given direction favors the perception of stimulus movement consistent with that direction. Ss simultaneously turned a crank and viewed a stimulus capable of apparent reversal of direction.Experiments 1A and 1B demonstrated that the perceived initial direction of rotation was more stable when it was consistent with the motor activity of the viewer than when it was inconsistent. Experiment 2 demonstrated that when Ss were instructed to perceive a particular direction of rotation for a period of time they tended to engage in motor activity consistent withthatdirection.The results were interpreted as supporting an efference theory of perception.     

Attention and multidimensional discrimination1

Observers’ ability to perform several discrimination tasks at the same time was tested using a two-alternative temporal forced-choice procedure. Discrimination of two auditory dimensions (pitch and intensity) and two visual dimensions (horizontal position and vertical position) was measured under conditions where one, two or all four dimensions required attention. Three signal durations were used: 67, 133, and 200 msec. Increasing the number of dimensions requiring attention systematically reduces the precisions of discrimination for each dimension. Auditory and visual discrimination is affected similarly. The amount of reduction in discrimination is independent of whether the dimensions requiring attention involve the same or different sensory modalities. The data are analyzed for evidence of a constant processing capacity employed in both single and multidimensional discrimination. The possibility that the observed performance levels could be achieved by sequentially processing the simultaneous inputs is also considered.     

Book reviews

Nervous and Hormonal Mechanisms of Integration: Symposia of the Society for Experimental Bilogy, No. 20. Edited by G. M. Hughes. London: Cambridge University press. 1966. Pp. viii + 553. 75s.

Essential Works of Pavlov. Edited with an Introduction by Muchael Kaplan. New York: bantam Books. 1966. Pp. xiii + 392. $1.25.

Psycholinguistic Papers. Proceedings of the Edinburgh Conference 1966. Edited by J. Lyons and R. J. Wales. Edinburgh University Press. 1966. Pp. 243. 42s.

On Human Communication. By Colin Cherry. 2nd edition. London and Cambridge, Mass.: M.I.T. Press. 1966. Pp. xiv + 337. 80s.

Psycholigical Principles Appropvite to Socal and Cinical Problems. By John C. Raven. London: H. K. Lewis. 1966. Pp. xx + 187. 25s.     

An infrared device for detecting locomotor activity

An electronic device for detecting locomotor activity in the home cage of small animals is described. The system involves a dense array of infrared (IR) beams designed to function as switches and capable of penetrating plastic walls of standard rodent cages without operational decrement. The device is reasonably inexpensive, is simple to calibrate, can be used with groups of animals, may be used for extended periods without maintenance, and is reliable with different cages.     

Book reviews

Metaphysics in Midwestern American by M.B. Wagner Ohio State University Press, S17.50 ISBN 0–8142–0346–9. pp229

The Religious Roots of Rebellion. Christians in the Central American Revolution by Philip Berryman. SCM Press, London. 1984, pp452, ISBN 334 00206 0 £12.50