Identification of integral stimuli

Conducted 2 experiments to confirm a holistic or "blob" processing model of stimulus identification in which discriminability is related to psychological distances between stimuli. In Exp I, 4 paid observers identified rectangles from linearly correlated and from equally redundant scattered sets of 6 stimuli. The holistic model was confirmed; parallel decision model predictions were confirmed only when congruent with the holistic model predictions. In Exp II, 5 observers identified line pairs from 5 different sets of 7 stimuli, which varied in redundancy and scatter, and rated pairwise dissimilarities among stimuli. Multidimensional scaling of the dissimilarities fitted a Euclidean better than a city-block metric, indicating that the stimuli were integral. These scaled dissimilarities predicted almost all differences in discrimination performance, reaction times and errors, between the first sets. Results confirm the "blob" model and demonstrate that frequently reported redundancy gains are due to an increase in psychological distances among stimuli and not to redundancy per se. A new definition of integrality based on relational dimensions is presented. (18 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1977 American Psychological Association.

Duke Scholars

Author Gregory R. Lockhead Psychology & Neuroscience