Description
- Abstract:
- This dissertation examines how brain regions respond to different types of competition during word comprehension and word production. A series of three studies attempted to enhance the current understanding of which brain regions are sensitive to different aspects of competition and how the nature of the stimuli and the context in which they occur can modulate their recruitment. Experiment 1 used a combined eye tracking and fMRI paradigm to study the neural basis of phonological competition during word comprehension. Experiment 2 also used a combined eye tracking and fMRI paradigm to study whether neural structures that were sensitive to the competition created by overtly presenting phonological onset competitors also responded to mediated phonological competition, i.e. competition in the absence of direct competitors in the visual array. While Experiments 1 and 2 focused on competition during word comprehension, Experiment 3 investigated the neural structures recruited by different types of competition (semantic, phonological, mediated semantic and phonological) during word production using the picture-word-interference task in fMRI. Overall, all three studies showed that competition during both word comprehension and word production recruits a similar network of areas in the posterior tempo-parietal and prefrontal cortices, mostly left-lateralized. Of particular interest was the role of the inferior frontal gyrus under conditions of competition. The present experiments confirm the role of this region as a selection mechanism under conditions of competition, and showed that this region responds to competition across linguistic domains and also to both direct and mediated types of competition. Moreover, the present results provide further support for the functional heterogeneity of the left IFG. More specifically, BA 44 responded to competition created only by manipulating phonological factors. BA 47 responded to competition created by both phonological and semantic factors, but critically this domain-general response was achieved only when the experimental task required selection among conceptual representations, as it was the case for both experiments 1 and 2. BA 45 showed increased activation across all conditions of competition, regardless of task and of response type.
- Notes:
- Thesis (Ph.D.) -- Brown University (2010)
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Citation
Righi, Giulia,
"The Neural Basis of Competition in Auditory Word Recognition and Spoken Word Production"
(2009).
Cognitive Sciences Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.7301/Z0QZ288W
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Cognitive Sciences Theses and Dissertations
Theses and Dissertations for the Cognitive Sciences department....