Effects of background music on phonological short-term memory

Immediate memory for visually presented verbal material is disrupted by concurrent speech, even when the speech is unattended and in a foreign language. Unattended noise does not produce a reliable decrement. These results have been interpreted in terms of a phonological short-term store that excludes non-speechlike sounds. The characteristics of this exclusion process were explored by studying the effects of music on the serial recall of sequences of nine digits presented visually. Experiment 1 compared the effects of unattended vocal or instrumental music with quiet and showed that both types of music disrupted STM performance, with vocal music being more disruptive than instrumental music. Experiment 2 attempted to replicate this result using more highly trained subjects. Vocal music caused significantly more disruption than instrumental music, which was not significantly worse than the silent control condition. Experiment 3 compared instrumental music with unattended speech and with noise modulated in amplitude, the degree of modulation being the same as in speech. The results showed that the noise condition did not differ from silence; both of these proved less disruptive than instrumental music, which was in turn less disruptive than the unattended speech condition. Theoretical interpretation of these results and their potential practical implications for the disruption of cognitive performance by background music are discussed.     

Differential encoding as a function of semantic polarity and form of visual stimulus presentation

The present study investigated the saliency of form of visual stimulus presentation (printed word or picture) and of the semantic evaluative dimension (positive or negative) as encoding attributes for fifth-grade children. Three short-term memory trials within one visual form of presentation or one pole of the evaluative dimension were followed by a fourth short-term memory trial on which the stimulus material was shifted on one or both attributes (experimentals) or held constant (controls). The recall of the experimental groups consistently exceeded that of the control groups on the shift trial, providing evidence for a release from proaetive inhibition and implying the saliency of both the form of visual stimulus presentation and the evaluative polarity of the stimulus concepts as encoding dimensions.     

Game Theory and Decentralisation

Whereas many environmentalists have traditionally argued in favour of small-scale, decentralised communities as a solution to the environmental crises which we appear to face, some environmental political theorists have recently argued against decentralisation. In this article I first show that game theory seems, at first glance, to support the insistence by statists that decentralisation is highly impracticable. But, second, I then attempt to demonstrate that, on closer inspection, game theory actually provides considerable support for the decentralist case.     

Book reviews

Byrne, R. W. and Whiten, A. (Eds.) (1988). Machiavellian intelligence: Social expertise and the evolution of intellect in monkeys, apes, and humans. Oxford: Clarendon press. Pp. xiv + 413. ISBN 0-19-852175-8, £25.00 (paperback).

Dudai, Y. (1989). The neurobiology of memory. Concepts, findings, trends. Oxford: Oxford University press. pp. xi + 340. ISBN 0-19-854261-5, £40.00 (hardback), ISBN 0-19-854229-1, £18.00 (paperback).

Richards, R. J. (1987). Darwin and the emergence of evolutionary theories of mind and behavior. Chicago & London: University of Chicago Press, Pp. xvii + 700. ISBN 0-226-71199-4. £23.95.

Archer, T. & Nilsson, L. (Eds.) (1989). Aversion, avoidance and anxiety: Perspectives on aversively motivated behavior. Hillsdale, NJ: Lawrence Erlbaum Associates, Inc. Pp. 491. ISBN 0-8058-0132-4. £29.95     

Book reviews

Boff, K. R., Kaufman, L., & Thomas, J. P. (Eds.). Handbook of perception and human performance. Volume 11: Cognitive processes and performance. New York: John Wiley and Sons, 1986. ISBN 0-471-82957-9. £81.25.

Lynch, Synapses, circuits and the beginnings of memory. Cambridge, Mass: The MIT Press, 1986. Pp. 122. ISBN 0-262-121 14-X. £22.50.