Poster A25, Thursday, August 16, 10:15 am – 12:00 pm, Room 2000AB
Masked identity priming survives the rotation of individual letters within words: An ERP investigation
Marta Vergara-Martinez1, Maria Fernandez-Lopez1, Ana Marcet1, Manuel Perea1;1Universitat de València
The process of visual word recognition is quite resilient to visual degradation (e.g., readers can automatically process CAPTCHAs; see Hannagan, Ktori, Chanceaux, & Grainger, 2012). A leading neural model of visual word recognition (Local Combination Detectors [LCD] model, Dehaene, Cohen, Sigman, Vinckier, 2005) makes a direct prediction with respect to a visual degradation manipulation: letter rotation. In the LCD model, the detectors of abstract letter units should be hindered by letter rotation beyond 40 degrees. To examine the impact of letter rotation during visual word recognition, we designed a masked priming ERP experiment with the lexical decision task in which we manipulated two factors: 1) prime-target relatedness (identity, unrelated); and 2) the rotation of individual letters in the primes (0-degree rotation [i.e. the standard format], 45-degree rotation, 90-degree rotation). The targets were always in lowercase with the standard (horizontal) format, whereas the primes were presented in uppercase with a smaller font size. If letter rotation slows down orthographic processing, one would expect small (or negligible) masked identity priming effects for those primes composed of rotated letters. For word targets, the behavioural results showed significant effects of letter rotation and identity priming in the response times: 1) letter rotation slowed down the processing of both identity and unrelated priming conditions; and 2) the magnitude of masked identity priming was sizeable for the three formats. More important, the ERP results showed a very early effect of letter rotation (N/P150 component: 0-degree rotation <> 45- and 90-degree rotation), along with a general latency delay of the N250 and N400 components for the rotated conditions. Interestingly, the identity priming manipulation had an impact on both the standard and the rotated formats (i.e., larger N400 amplitude for the unrelated priming condition). Taken together, the masked identity priming effects obtained when the individual letters of the primes were rotated reveal that, despite the dramatic changes induced by letter rotation, the cognitive system is able to encode orthographic information in the very early stages of visual processing.
Topic Area: Perception: Orthographic and Other Visual Processes