Knowing what is new: the effects of item-relatedness on the neural correlates of novelty detection

Open Access
Author:
Bowman, Caitlin Rose
Graduate Program:
Psychology
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
November 30, 2012
Committee Members:
  • Nancy Anne Coulter Dennis, Thesis Advisor
Keywords:
  • episodic memory
  • fMRI
  • retrieval
Abstract:
Accurate memory depends both on the ability to correctly endorse previously encountered information as old and correctly identify novel information as new. Behavioral memory research has shown that similarity between old and new information makes novelty detection more difficult, leading to a greater number of novel items misidentified as old. However, the cognitive and neural processes subserving successful novelty detection are not well understood and have yet to be examined in the context of relatedness to old items. The present study used fMRI to investigate the neural basis of novelty detection when items were either related or unrelated to items presented at study. Results showed general novelty regions that included right anterior medial temporal lobe, left middle temporal gyrus, and right early visual cortex, suggesting increased encoding processes for novel items independent of item-relatedness. Related novelty was associated with a vast set of regions including bilateral early and late visual cortex, bilateral ventrolateral prefrontal cortex (VLPFC), and bilateral superior parietal cortex, indicating engagement of visual details, cognitive control, and top-down attention to support successful related novelty detection. Finally, unrelated novelty was associated with regions including bilateral inferior and middle temporal gyrus, right superior temporal gyrus, and bilateral inferior parietal cortex, indicating engagement of semantic and categorical processing and bottom-up attention to support unrelated novelty detection.