Maturation of neural indices for processing verb-agreement violations: Evidence from event-related potentials elicited in adolescents and adults

Erin Lynn Meier, Purdue University

Abstract

While verbs are necessary in even the most basic sentences, they are one of the most complex elements of spoken language. Verbs carry important information regarding the meaning (i.e., semantics) and structure (i.e., syntax) of sentences as well as how semantics and syntax are interrelated. In previous research, the study of verb usage and comprehension has elucidated developmental differences between children and adults. However, very little is known about the adolescent brain regarding verb processing; current research suggests that the underlying mechanisms mediating speech production and the neurophysiology responsible for language comprehension are still developing during adolescence despite outwardly mature use of syntax. Therefore, the purpose of the present study was to highlight the differences in ERP indices of auditory comprehension of verb agreement between adolescents and adults matched for accuracy of grammaticality judgments. In both groups, verb-agreement violations elicited a slight anterior negativity (AN) that did not reach significance as well as a large late positive component (LPC). The time course of the LPC differed significantly between groups in that the adolescents' LPC began and peaked later and ended before the LPC in the adults. Moreover, an unexpected finding is that verb-agreement errors elicited an N400, a component believed to index the ease of semantic integration, in the adolescent group; this component was not present in the adult waveforms. These N400 and LPC results support behavioral work regarding adolescent use of syntax and indicate that the neurological system mediating auditory comprehension of verbs is still developing in late adolescence into early adulthood.

Degree

M.S.

Advisors

Weber-Fox, Purdue University.

Subject Area

Speech therapy

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