Theta and alpha frequency modulation by lexical-syntactic information during a lexical decision task

Abstract

We studied theta and alpha event related increases (ERS) and decreases (ERD) in band power associated with a prime-target mismatch at the lexical-syntactic level during a lexical decision task. Participants saw 100 prime-target pairs that shared all lexical- syntactic information (Same condition) or differed only in verbal mode (Different condition). Reaction times decreased to targets of the Same compared to the Different group showing activation of verbal mode during the task. A significantly greater alpha ERD was obtained in the Same compared to the Different condition from 800 to 1200 ms after target presentation. We interpret this result as a neurobiological indicator of a repetition effect at the lexical-syntactic level.

Keywords

• Lexical decision task
• Verbal mode
• Time-frequency analysis
• Alpha desynchronization