Abstract
Thurstone’s factor-analytic discoveries regarding primary visual abilities, gestalt effects, and perceptual dynamics seem clearly forgotten yet important for identifying and understanding processes underlying human perceptual organization. The present study used correlational and modern factor analytic methods to reanalyze the data of Thurstone (1944), which measured 194 individuals’ performance on 60 visual tests. 11 Factors were deemed significant, and were varimax-rotated to simple structure. Visual factors were obtained for 1) geometrical illusions, 2) perceptual switch rates (i.e., between ambiguous binocularly rivalrous percepts]), and 3) holistic 'Gestalt closure,' among others. Some factors showed clear gender differences, while all were independent of general intelligence (and thus are 'specific abilities'). The three factors have now been replicated and 'rediscovered' in other large, classic data sets reanalyzed by the author. Discrepancies between factors obtained from these reanalyses and those from recent studies (e.g., those which find no common factor for illusions) are discussed. The visual factors that are determined by processing rate seem to differ from those obtained in visual tasks that are not time-limited. Reanalyses like these seem useful for identifying distinct visual-cognitive processes of interest to current vision researchers, as they use variability to link front-end visual processes to higher level perceptual and cognitive processes. Results are presented as part of a larger project, reanalyzing 11 classic visual studies by Thurstone and colleagues (1938-1957) as well as other available, relevant data (Carroll, 1993; Buckley et al, 2018) using modern, fast, improved factor analytic methods. In these reanalyses so far, broad general visual factors have not been found, nor have factors highly correlated with general intelligence been found. But it is evident that there are common factors linked to specific visual processes or abilities.