Fluent readers are sensitive to the lexical and orthographic properties of written words. How efficient can a native reader distinguish a real word from pseudo words (lexical sensitivity), false words (orthographic sensitivity), and stroke combinations (visual form sensitivity)? In the current study, we adopted a visual search paradigm to investigate the efficiency of lexical and orthographic information processing associated with Chinese characters. Fifteen Chinese native readers took part in this project. In the first experiment, participants were asked to search for a real Chinese character among a number of distractors. The distractors were either pseudo characters, false characters or stroke combinations which were run in separated blocks. In each search display, 3, 6 or 9 items were present. In the second experiment, target-distractor mapping was reversed and observers searched for a non-character among real characters. Results revealed large differences in the search efficiency among the three different search conditions. The slopes of search times as a function of set size for the three search conditions were significantly different. Specifically, searching for a real character among stroke combinations was the fastest (shallowest slope) while searching for a real character among pseudo characters took participants the most time (steepest slope) compared to the other two search conditions. Although overall more efficient, similar results were obtained when participants searched for non-characters among real characters. This pattern of results suggests that for Chinese characters the visual form judgment is the most efficient (real character vs. stroke combination, about 100 ms per item), while the lexical processing is the least efficient (real character vs. pseudo-character, about 200 ms per item), with the orthographic judgment in the middle (real character vs. false character, about 150ms per item).
This research was supported by NSF grant BCS-0818588.