Visual interference disrupts visual and only visual knowledge
21.24, Saturday, 16-May, 8:15 am - 9:45 am, Talk Room 2
Pierce Edmiston1, Gary Lupyan1; 1Department of Psychology, University of Wisconsin-Madison
Visual imagery and the making of visual judgments involves activation of cortical regions that underlie visual perception (e.g., reporting that taxicabs are yellow recruits color sensitive regions of cortex, Simmons et al., 2007). Such results, however, leave open the critical question of whether perceptual representations are constitutive of visual knowledge (Barsalou, Simmons, Barbey, & Wilson, 2003; Mahon & Caramazza, 2008). We report evidence that visual interference disrupts the activation of visual and only visual knowledge. Recognizing an upright object next to a rotated picture of the same object is known to be aided by cueing; hearing word cues that match the subsequently presented pictures (e.g., hearing “alligator” prior to seeing pictures of alligators) improves performance, whereas hearing invalid cues (e.g., hearing “alligator” prior to seeing pictures of dogs) impairs it. We show that we can reduce this cueing effect by 46% by presenting a visual mask during or after the auditory word cue. The mask did not affect performance on no-cue trials, showing that the effect of the visual interference disrupts the knowledge activated by the word. In subsequent studies we show that the same type of visual interference affects knowledge probed by verbal propositions. For example, hearing the word “table” while viewing visual noise patterns made participants 1.4 times more likely to make an error in affirming the visual property that tables have flat surfaces but not the more general (and equally difficult) property that tables are furniture. These results provide a convincing resolution of a longstanding debate in cognitive psychology and neuroscience about the format of visual knowledge. Although much of our knowledge abstracts away from perceptual details, knowledge of what things look like appears to be represented in a visual format.