Complex Time-Dependent ERP Hemispheric Asymmetries during Word Matching in Phonological, Semantic and Orthographical Matching Judgment Tasks

Language-induced asymmetry to single word reading has been well investigated in past research. Less known are the complex processes and related asymmetries occurring when a is compared with previous one, according specific tasks. To this end, we used paradigm based on 80 sequential pair comparisons three blocked tasks: phonological, semantic orthographical matching judgment. Participants had decide whether target (W2) did or not match prime (W1), presented 2 sec before, task. The event-related potentials (ERPs) evoked by W2 20 participants have analyzed. first negative wave, Recognition Potential (RP), peaking at about 120 ms over parietal sites, showed greater amplitude left sites all tasks, thus revealing typical left-lateralization. At frontal only phonological task lateralization. following N400 (300–450 ms) an interesting interaction: Match trials elicited regions than visual-perceptual whereas mismatch induced inverted asymmetry, marked right regardless of Concerning late (450–600 ms), tasks overlapping pattern, lateralization conditions. Results point task- time-dependent hemispheric matching.