Consonantal overlap effects in a perceptual matching task.

This study investigates the processing of letter position coding by exploring whether or not two explicitly presented words that share the same consonants, but that differ in their vowels, exert mutual interference more than two words that do not share their consonants. In an explicit perceptual matching task, word targets were preceded by a word reference that could share all the consonants either at the same position or in a different absolute position (while keeping their relative position intact) or preceded by an unrelated reference. Experiment 1 showed larger discrimination costs for pairs sharing the consonants at the same position than for pairs sharing their consonants in a different position. Experiment 2 investigated when and how the types of overlap influence word target processing by using event-related potential recordings. The ERP results showed a Relatedness effect only for targets that share the consonants at the same position from 120 to 600 ms post-target onset, whereas targets that share their consonants in different positions in the string produced null effects. Altogether, these data suggest that targets containing the same consonants included in the references in the same positions are processed as being highly similar to them, thus distorting target processing. Furthermore, these data suggest possible mechanisms of competition between lexical representations of the reference and target stimuli.