Content representation in the human medial temporal lobe

The transformation of sensory inputs into complex memory representations is fundamental to human experience; yet, little is known about how this crucial process is achieved. When you meet your friend at the new cafe in town, what part of the brain encodes this novel scene into long term memory? What part encoded your friend’s favorite t-shirt, so that the sight of it gives you a feeling of familiarity rather than surprise? It is well-established that the medial temporal lobe (MTL) is crucial to both processes, but the MTL is not a single homogeneous region. In fact, it is composed of several anatomically distinct subregions including hippocampus, perirhinal cortex (PRC) and parahippocampal cortex (PHC). However, the computations performed by each subregion to encode individual events is still unclear. The present research tests the central hypothesis that different forms of event content are transformed into memory by distinct subregions within the MTL. A critical barrier in the study of content representation thus far has been its focus on comparing univariate peak activations in a region to different stimulus materials. To go beyond this limited approach, we employed multivariate statistical analyses that takes into account how event content is represented by distributed activity in MTL subregions. First, we examine the content-specific contributions of MTL subregions to episodic encoding and retrieval. Then, we demonstrate how these distributed representations support memory-based prediction to resolve ambiguities in our environment.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Neuroscience

Grantor

The University of Texas at Austin

Year dc:date.issued

2015

Author dc:creator

• Liang, Jackson Chit

Advisor dc:contributor.advisor

• Preston, Alison R.

Committee members dc:contributor.committeemember

• Colgin, Laura L
• Drew, Michael R
• Poldrack, Russell A
• Schnyer, David M

• fMRI
• Memory
• Hippocampus
• Human memory
• Sensory inputs
• Medial temporal lobe
• Perirhinal cortex
• Parahippocampal cortex
• Event encoding
• Event content
• Memory representations
• Content representation
• Multivariate statistical analyses
• Memory-based prediction

Language dc:language.iso

en

Identifier

doi:10.15781/T22R3P31H

OAI identifier oai:identifier

oai:repositories.lib.utexas.edu:2152/47195