Examining the Transient Neural Dynamics Underlying Working Memory Maintenance for Complex Visual Stimuli
type: CreativeWork
description: Working memory (WM) is the temporary storage of information to accomplish a future goal. The WM delay period is the time after encoding but before retrieval when information is being maintained, typically in the absence of relevant stimuli. Understanding how the brain supports maintenance during the delay period, and how neural activity and connectivity are related to memory is critical for advancing both basic knowledge as well as informing declines in memory and cognition related to neurodegenerative diseases and healthy aging. An open question in the field of WM research is how information is stored during this delay period. One theory suggests persistent neural activity supports the storage of information while another theory suggests rapid synaptic weight changes (i.e., an activity-silent mechanism). While support exists for both theories, numerous confounds complicate the experiments designed to distinguish between these two theories. Most notably, studies typically use simple stimuli with short, predictable, unfilled delay periods, with few studies examining this open question using complex visual stimuli. For this dissertation four EEG experiments were conducted to answer three questions: 1) Does the type of maintenance technique used during the delay period modulate the neural activity for complex visual stimuli? 2) What are the load-dependent delay activity and connectivity patterns associated with maintenance of complex visual stimuli? And 3) How do patterns of delay activity and connectivity change when attention is sustained during unpredictable delay period durations? In the first set of experiments, we examined the role of rehearsal in maintaining complex visual stimuli. We looked at the impact of rehearsal versus suppression of rehearsal using novel naturalistic scenes that contained semantic content and phase-scrambled scenes that lacked semantic content. The benefit of rehearsal was associated with increases in theta and alpha band amplitude, but o…
abstract: Working memory (WM) is the temporary storage of information to accomplish a future goal. The WM delay period is the time after encoding but before retrieval when information is being maintained, typically in the absence of relevant stimuli. Understanding how the brain supports maintenance during the delay period, and how neural activity and connectivity are related to memory is critical for advancing both basic knowledge as well as informing declines in memory and cognition related to neurodegenerative diseases and healthy aging. An open question in the field of WM research is how information is stored during this delay period. One theory suggests persistent neural activity supports the storage of information while another theory suggests rapid synaptic weight changes (i.e., an activity-silent mechanism). While support exists for both theories, numerous confounds complicate the experiments designed to distinguish between these two theories. Most notably, studies typically use simple stimuli with short, predictable, unfilled delay periods, with few studies examining this open question using complex visual stimuli. For this dissertation four EEG experiments were conducted to answer three questions: 1) Does the type of maintenance technique used during the delay period modulate the neural activity for complex visual stimuli? 2) What are the load-dependent delay activity and connectivity patterns associated with maintenance of complex visual stimuli? And 3) How do patterns of delay activity and connectivity change when attention is sustained during unpredictable delay period durations? In the first set of experiments, we examined the role of rehearsal in maintaining complex visual stimuli. We looked at the impact of rehearsal versus suppression of rehearsal using novel naturalistic scenes that contained semantic content and phase-scrambled scenes that lacked semantic content. The benefit of rehearsal was associated with increases in theta and alpha band amplitude, but o…
author: Reichert Plaska, Chelsea
keywords: Cognitive Neuroscience, Cognitive Psychology, Working Memory Maintenance, Attention, Delay Activity, Functional Connectivity, Rehearsal, Interference
date published: 2021-06-01T07:00:00Z
date modified: 2026-07-24T01:59:38Z
provider: City University of New York - Graduate Center
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The Graduate School and University Center of The City University of New York