Book reviews

Gordon, I. E. (1989). Theories of visual perception. Chichester: John Wiley & Sons. Pp. 273. ISBN 0-471-92196-3. £12.50.

Shepp, B. E. & Ballasteros, S. (Eds.) (1989). Object perception: Structure and process. Hillsdale, NJ: Lawrence Erlbaum Associates. Pp. 431. ISBN 0-8058-0060-3 (hardback) £44.95; ISBN 0-8058-0333-5 (paperback) £22.95.

Frith, U. (1989). Autism: Explaining the enigma. Oxford: Basil Blackwell. Pp. 204. ISBN 0-631-15833-2. £25.00 (hardback); £8.95 (paperback).

Rollins, M. (1989). Mental imagery: On the limits of cognitive science. New Haven, CT: Yale University Press. Pp. 170. ISBN 0-30-04491-7. £18.00.

Lloyd, D. (1989). Simple minds. Cambridge, MA: The MIT Press. Pp. 266. ISBN 0-262-12140-9. £22.50.

Howard, D. & Franklin, S. (1988). Missing the meaning? A cognitive neuropsychological study of the processing of words by an aphasic patient. Cambridge, MA & London: MIT Press. Pp. xix + 171. ISBN 0-262-08178-4. £22.50.

Evans, J. St. B. T. (1989). Bias in human reasoning. Hove and London: Lawrence Erlbaum Associates Ltd. ISBN 0-86377-106-8. £14.95 (hardback) ISBN 0-86377-156-4. £8.95 (paperback).

Clark, A. (1989). Micorcognition: Philosophy, cognitive science, and parallel distributed processing. Cambridge, MA: MIT Press/Bradford Books. Pp. 226. ISBN 0-262-03148-5. £14.95.     

The detection of a tone added to a narrow band of noise: The energy model revisited

In an effort to determine whether cues related to changes in energy contribute to the detection of a tone added to a narrow band of noise, we examined the effect of level variation on detection thresholds. In the first experiment, the level of each waveform was randomly varied on each presentation. Level variation had only marginal effects on performance. In addition, detection thresholds were obtained using bands of noise with equal energy across intervals. Neither increasing nor decreasing the variance of the noise-alone and tone-plus-noise energy difference distributions altered the detectability of a tone added to noise. Thus, the changes in energy that are concomitant with the addition of the tone are not the sole cue for the detection of the tone. In a second experiment, three psychometric functions were measured. One function was determined using no level variation, one was measured in the presence of level variation, and one was measured in the context of level variation, but for trials without level variation. The context of level variation slightly reduced detectability. In a third experiment, we compared detectability in three conditions: no level variation, across-trial level variation, and across-interval level variation. The thresholds obtained in the absence of level variation were superior to those measured in the presence of level variation, regardless of the manner in which the level variation was incorporated.     

Food, mood, and attitude: reducing risk for eating disorders in college women.

Food, Mood, and Attitude (FMA) is a CD-ROM prevention program developed to decrease risk for eating disorders in college women. Female 1st-year students (N = 240) were randomly assigned to the intervention (FMA) or control group. Equal numbers of students at risk and of low risk for developing an eating disorder were assigned to each condition. Participants in the FMA condition improved on all measures relative to controls. Significant 3-way interactions (Time x Condition x Risk Status) were found on measures of internalization of sociocultural attitudes about thinness, shape concerns, and weight concerns, indicating that at-risk participants in the intervention group improved to a greater extent than did low-risk participants. At follow-up, significantly fewer women in the FMA group reported overeating and excessive exercise relative to controls.     

Normative Transmission and Necessary Means

Philosophia - This paper focuses on the interaction of reasons and argues that reasons for an action may transmit to the necessary means of that action. Analyzing exactly how this phenomenon may be...