The psychophysics of imagery

A clínica da psicofísica

Apresentamos a Psicofísica como uma ciência aplicada nas investigações e nas abordagens e diagnósticos clínicos. Inicialmente, introduzimos algo dos aspectos epistemológicos e teóricos da área, passamos para as abordagens que a Psicofísica pode apresentar na aplicabilidade clínica e, por fim, discutimos os avanços recentes da aplicação clínica, apresentamos as experiências de nosso laboratório de pesquisa clínica em psicofísica, finalizando com as perspectivas de ampliação do uso da psicofísica para investigações clínicas de funções perceptuais mais complexas.

Olfactory imagery: a review

Olfaction's unique cognitive architecture, the apparently inconsistent evidence favoring imagery, and its difficulty of evocation have led some to conclude that there is no capacity for olfactory imagery. Using three streams of evidence, we examine the validity of this claim. First, self-reports of olfactory imagery can resemble those obtained for actual perception. Second, imagining an odor can produce effects similar to actual perception. Third, olfactory perception and memory-based images can interact. A model of olfactory imagery is then presented that utilizes the same systems employed in actual perception, with similar constraints. This model is consistent with olfaction's unique information-processing capacities and can account for previous experimental inconsistencies on the basis of difficulty of evocation, a consequence of unstable access to semantic information. In sum, the evidence presented here is favorable to the existence of an olfactory imagery capacity.

Development and testing of a labeled magnitude scale of perceived satiety

Satiety ratings are often made using VAS or simple category scales. In order to establish a simple, more quantitative technique to index perceived hunger and/or fullness, research was undertaken to develop and test a labeled magnitude scale of satiety. Thirty-seven subjects rated the semantic meaning of 47 phrases describing different levels of hunger/fullness using magnitude estimation. Eleven phrases were then selected using criteria of response consistency, symmetry, bipolarity, and inclusion of the end-point anchors of 'greatest imaginable hunger (fullness)'. These phrases were placed along a vertical line scale at positions corresponding to their geometric mean magnitude estimates to create a labeled magnitude scale of satiety. This Satiety Labeled Intensity Magnitude (SLIM) scale was compared to VAS scales for sensitivity and reliability in two studies. In one image-based study, ANOVA with post-hoc tests showed the SLIM scale to have greater sensitivity and to have an average reliability coefficient of 0.90. In a second study using three different foods replicated on two consecutive weeks, reliability was found to be highest for the SLIM scale. It is concluded that the SLIM scale is a sensitive, reliable, and easy-to-use scale for measuring perceived satiety that has several advantages over other, more commonly used satiety scales.