Evaluating comparative and equality judgments in contrast perception: attention alters appearance.

摘要: Covert attention not only improves performance in many visual tasks but also modulates the appearance of several features. Studies on and have assessed subjective using a task contingent upon comparative judgment (e.g., M. Carrasco, S. Ling, & Read, 2004). Recently, K. A. Schneider Komlos (2008) questioned validity those results because they did find significant effect contrast an equality task. They claim that such judgments are bias-free whereas bias-prone propose alternative interpretation previous findings based decision bias. However, to date there is no empirical support for superiority procedure. Here, we compare biases sensitivity shifts perceived both paradigms. We measured judgment. Observers judged contrasts two simultaneously presented stimuli, while either one stimulus was physically incremented (Experiments 1 2) or exogenous drawn it 3 4). demonstrate methodological limitations paradigm. Nevertheless, paradigms capture PSE due physical changes show enhances apparent contrast.