Poster A72, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
N400 Effects on Conceptual Expansion
Alejandro Heredia Cedillo1, Kristina Pfeifer1, Gavin Dowd1, Reza Ghafur1, Mark W. Geisler1; 1San Francisco State University
Conceptual expansion is defined as broadening our existing knowledge structures about the world by integrating novel information (Ward, 1994). The amplitude of the N400 Event-Related Potential becomes larger when semantic meaning is violated in a contextual setting (Kutus & Federmeier, 2000). However little research has been done on N400 amplitude and its sensitivity to conceptual expansion. If N400 amplitude is not solely sensitive to violations in semantic expectancies then smaller N400 amplitudes should occur when conceptual expansion is successfully employed. Participants (N = 45) were asked to try and form an association when viewing related, indirect, and unrelated word pairs while electroencephalography was recorded from 9 electrode sites: Fz, Cz, Pz, F3, F4, C3, C4, P3 and P4. Conceptual expansion was defined as making an association between indirect or unrelated word pairs via verbal response. Subtraction waveforms were used for analysis, which left two conditions of interest: the unrelated effect (unrelated minus related) and the indirect effect (indirect minus related). A tertiary split determined high and low response groups for the indirect (high = 24, low = 6) and unrelated (high = 18, low = 15) conditions. Smaller N400 amplitude was found for high verses low groups, with trending effects in the indirect condition (p = .067) and significant effects in unrelated condition (p = .016). For the indirect condition, this effect was significant over the parietal lobe, while in the unrelated condition trending effects were broadly distributed over the scalp.
Topic Area: LANGUAGE: Semantic