Morphological agreement at a distance: Dissociation between
early and late components of the event-related brain potential
Polly L. O'Rourke
, Cyma Van Petten
Center for Advanced Study of Language, University of Maryland, College Park, MD, USA
Binghamton University, State University of New York, Binghamton, NY, USA
ARTICLE INFO ABSTRACT
Accepted 30 March 2011
Available online 3 April 2011
Syntactic relationships among non-adjacent words are a core aspect of sentence structure.
Research on complex sentences with displaced elements has concluded that resolving long-
distance dependencies can tax working memory. Here we examine a simpler relationship—
morphological agreement between the elements of a noun phrase—across a gradient of
distance. Participants read sentences with violations of gender agreement among Spanish
nouns, determiners and adjectives. For those explicitly assigned the task of detecting errors,
accuracy was uniformly high across the four levels of distance between (dis)agreeing words.
A second group performed a comprehension task as ERPs were recorded. Gender agreement
errors elicited a left anterior negativity (LAN) regardless of the distance between (dis)
agreeing words, indicating that the errors were detected. In contrast, a temporally later
component of the ERP (P600) showed decreasing amplitudes as the number of words
between (dis)agreeing elements increased. Smaller P600 responses were also associated
with slower responses to the comprehension questions. Given other work suggesting that
the P600 indexes attempted repair of a problematic sentence structure, the results suggest
that the participants became increasingly unwilling to re-visit their initial parse of a
sentence as the required effort increased, despite having noted an error. The results are
discussed within the context of studies showing that readers often compute inadequate
structural representations of sentences. We suggest that P600 amplitude may reflect the
costs versus benefits of sentence re-analysis, determined by a combination of sentence
structure, task requirements, and the degree to which sentence meaning hinges on a correct
© 2011 Elsevier B.V. All rights reserved.
Most of the world's languages use morphological agreement to
flag relationships among words in sentences. For instance,
although the morphology of English is simplified relative to
many languages,it retains a few overt agreement requirements,
such as person and number agreement between nouns and
verbs (e.g., the student says versus the students say versus Isay).
Other languages possess richer morphological systems, such
that German includes six forms of the indefinite article ein (“a”),
BRAIN RESEARCH 1392 (2011) 62– 79
⁎ Corresponding author at: Department of Psychology, Science IV, Binghamton University, 6600 Vestal Parkway East, Binghamton,
NY 13902, USA.
E-mail address: firstname.lastname@example.org (C. Van Petten).
0006-8993/$ – see front matter © 2011 Elsevier B.V. All rights reserved.
available at www.sciencedirect.com