Slide Slam J13 Sandbox Series
Is there magnocellular facilitation in early visual word recognition? Evidence from ERPs
Xin Huang1, Olaf Dimigen2, Werner Sommer2, Alan Chun-Nang Wong1, Wai Leung Wong1, Chun-Yu Tse3, Urs Maurer1; 1The Chinese University of Hong Kong, 2Humboldt-Universität zu Berlin, 3City University of Hong Kong
An influential theory in the field of visual object recognition proposes that fast magnocellular (M) information facilitates processing of spatially more fine-grained but slower parvocellular (P) information. While visual words can be considered to be a special type of visual objects, it is unknown whether magnocellular facilitation also plays a role in reading. We used a masked-priming experiment that has been shown to result in neural facilitation and tested whether these facilitation effects were mediated by the magnocellular system. In two experiments, the influence of magnocellular and parvocellular systems on visual word recognition was measured by contrasting the influence of either high vs. low spatial frequency primes (exp. 1) or luminance vs. color contrast primes (exp. 2). In each experiment, we presented unchanged primes in addition to M- and P-biased primes to measure basic neural facilitation. We replicated typical repetition effects in the N1, N250 and N400 components of the ERP with unchanged primes in both experiments. In exp. 1, we obtained repetition effects only in the N1 for both M- and P-biased primes. In exp. 2, the repetition effects were found in both N1 and N250 for both M- and P - biased primes. However, no interaction between prime type (M-biased vs. P-biased) and repetition was found, indicating that both M- and P- biased information together contribute to early visual word recognition.