AN fMRI INVESTIGATION OF CATEGORY-SPECIFIC EPISODIC ENCODING

Open Access
Author:
Harris, Jonathan David
Area of Honors:
Psychology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Nancy Anne Coulter Dennis, Thesis Supervisor
  • David A. Rosenbaum, Honors Advisor
Keywords:
  • episodic encoding
  • fMRI
  • catgory specific
Abstract:
Determining whether certain categories of words have discrete neural representations (processing dedicated to different brain regions) is the pursuit of this thesis. Twelve participants were scanned using functional magnetic resonance imaging (fMRI) to discriminate between the neural correlates of words representing either animals or objects during episodic encoding. Consistent with semantic retrieval studies, neural activity associated specifically with objects was encoded predominantly in the posterior portion of the left hemisphere: the superior frontal gyrus, parahippocampal gyrus, fusiform gyrus, posterior cingualte cortex, occipitotemporal cortex, precuneus, and occipital cortex. Activity associated specifically with animals, however, was encoded predominantly in anterior portion of the right hemisphere: the dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC), medial prefrontal cortex, and the posterior midline. Although the regions for animal activity are inconsistent with previous studies, data show that each category exhibits its own processing regions, suggesting that category specificity occurs not only during semantic retrieval, but also during episodic encoding of words.