Individual differences in motion induced blindness: Small-sample factor analysis of stereoscopic depth and mask coherence data reveals separate processes for frequency and duration of blindness episodes

[摘要] Motion-induced blindness (MIB) occurs when a moving pattern of visual elements (mask) causes the perceived disappearance and reappearance of stationary targets. Sparrow et al. (2017, Vision Research) investigated the effects of stereoscopic depth ordering of targets relative to the mask plane (Front, Behind, Same), and motion coherence of the mask elements (0%, 50%, 100%). For each of the 3×3 conditions, both the frequency (number of blindness episodes) and duration (disappearance time) of MIB events were measured in 9 individuals. For each individual/condition, measures were obtained for sixty thirty-second presentations (30 minutes total). Although the original study of Sparrow et al. analyzed mean group differences, our reanalysis used correlations and factor analysis to examine underlying processes. Two principal components explained 85% of the total variance in a data set combining frequency and duration. One obliquely-rotated (promax) factor (F1) defining MIB duration was clearly separate from the other (F2) defining MIB frequency. The two oblique factors were inter-correlated, r=0.65, indicating two separate but not independent factors, or processes. From this, we conclude that the processes that primarily initiate MIBs (and determine the frequency of MIB episodes) seem to be different than the ones that primarily terminate MIB episodes (and thus determine the duration of MIB episodes).

[学科分类] 眼科学