Bubbles: a technique to reveal the use of information in recognition tasks

Everyday, people flexibly perform different categorizations of common faces , objects and scenes. Intuition and scattered evidence suggest that these c ategorizations require the use of different visual information from the inp ut. However, there is no unifying method, based on the categorization perfo rmance of subjects, that can isolate the information used. To this end, we developed Bubbles, a general technique that can assign the credit of human categorization performance to specific visual information. To illustrate th e technique, we applied Bubbles on three categorization tasks (gender, expr essive or not and identity) on the same set of faces, with human and ideal observers to compare the features they used. (C) 2001 Elsevier Science Ltd. All rights reserved.