title: Frequency and Chunking in Derived Words: A Parametric fMRI Study.
abstract: In usage-based linguistic theories, the assumption that high-frequency language strings are mentally represented as unitary chunks has been invoked to account for a wide range of phenomena. However, neurocognitive evidence in support of this assumption is still lacking. In line with Gestalt psychological assumptions, we propose that a language string qualifies as a chunk if the following two conditions are simultaneously satisfied: The perception of the whole string does not involve strong activation of its individual component parts, but the component parts in isolation strongly evoke the whole. Against this background, we explore the relationship between different frequency metrics and the chunk status of derived words (e.g., "government," "worthless") in a masked visual priming experiment with two conditions of interest. One condition investigates "whole-to-part" priming (worthless-WORTH), whereas the other one analyzes "part-to-whole" priming (tear-TEARLESS). Both conditions combine mixed-effects regression analyses of lexical decision RTs with a parametric fMRI design. Relative frequency (the frequency of the whole word relative to that of its onset-embedded part) emerges as the only frequency metric to correlate with chunk status in behavioral terms. The fMRI results show that relative frequency modulates activity in regions that have been related to morphological (de)composition or general task performance difficulty (notably left inferior frontal areas) and in regions associated with competition between whole, undecomposed words (right inferior frontal areas). We conclude that relative frequency affects early stages of processing, thereby supporting the usage-based concept of frequency-induced chunks.
authors.affiliation: University of Freiburg.
authors.forename: Alice
authors.initials: A
authors.lastname: Blumenthal-Dramé
authors.affiliation: University of Freiburg.
authors.forename: Volkmar
authors.initials: V
authors.lastname: Glauche
authors.affiliation: University of Freiburg.
authors.forename: Tobias
authors.initials: T
authors.lastname: Bormann
authors.affiliation: University of Freiburg.
authors.forename: Cornelius
authors.initials: C
authors.lastname: Weiller
authors.affiliation: University of Freiburg.
authors.forename: Mariacristina
authors.initials: M
authors.lastname: Musso
authors.affiliation: University of Freiburg.
authors.forename: Bernd
authors.initials: B
authors.lastname: Kortmann
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008037:Linguistics; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011930:Reaction Time; D011932:Reading; D060865:Repetition Priming / Q000502:physiology; D055815:Young Adult