The Effect of Conditioned Stimulus Intensity upon a Simple Running Response

An experiment was designed to answer two questions regarding the correspondence between concrete and abstract actions. No significant differences were found, but because of deficiency of method, no conclusive answers could be given. The total scoring frequencies were in good accord with the results from the conditions 1 and 1* in the previous study [see earlier study for explanation of designations (2)], corroborating the evidence of that study regarding determinants of horizontal decalage.     

Book reviews

Sutherland, S. (1989). Macmillan dictionary of psychology. London: Macmillan Reference Books. ISBN -333-38829-1. £ 29.95

Van Toller, S. & Dodd, G. H. (Eds.). (1988). Perfumery: the psychology and biology of fragrance. London: Chapman and Hall. Pp. 268. ISBN 0-412-30010-9. £ 35.00

Watt, R. J. (1987). Visual processing: Computational, psychophysical and cognitive resedrch. Hove: Lawrence Erlbaum Associates Ltd. Pp.160. ISBN 0-86377-081-9. £ 14.95/$ 26.95

Caplan, D. & Hildebrandt, N. (1988). disorders of syntactic comprehension. Cambridge, MA: MIT Press/Bradford Books. Pp. 340. ISBN 0-262-03132-9. £31.50     

Ideational fluency in Parkinson's disease.

Recent research on Parkinson's disease (PD) suggests that executive functions are impaired but that visuospatial functions may be spared. This dissociation has been attributed to dysfunction in ascending dopaminergic pathways affecting the prefrontal cortex. We investigated these ideas in a sample of intellectually intact patients with idiopathic, optimally treated PD (N = 20) and in spouse controls (N = 15); the groups were divided into young (age < 60) and old subgroups, each comparable on education, vocabulary level, and Mini-Mental State scores. Six tasks were selected from a set of factor-referenced cognitive tests to measure three abilities: (1) ideational fluency (ability to generate ideas), (2) flexibility of use (ability to shift mental set), and (3) spatial orientation (ability to perceive spatial patterns). PD patients were impaired only on the ideational fluency factor (p = .01). An age-related deficit was seen on the spatial factor (p < .05) with a trend on the flexibility factor (.05 < p < .10). No interactions were significant. The findings suggest that when age and verbal intelligence are controlled, PD patients show no deficit on purely spatial tasks; in contrast, patients seem less able to generate ideas though capable of shifting from one idea to another.     

Thresholds for movement direction: Two directions are less detectable than one

Thresholds for detecting movement direction were measured for two different types of dynamic dot display; first, one in which all dots moved upwards, and secondly, one in which half the dots moved upwards and half moved downwards. Direction sensitivity was found to be worse for the stimulus containing two simultaneous directions of motion than for the stimulus in one direction. These data are taken as evidence of some form of competition, or AND-NOT gating, between the outputs of direction-specific analysers during threshold determination.