Dynamic Changes of Total Power in Hippocampus During Resting State vs. Memory Tasks Using High Density Electroencephalography (HDEEG)
Abstract number :
2.081
Submission category :
3. Neurophysiology / 3G. Computational Analysis & Modeling of EEG
Year :
2022
Submission ID :
2203986
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:22 AM
Authors :
Hua Huang, PhD – Stanford University; Jordan Seliger, MA – Neurology – Stanford University; Adam Fogarty, BA – Stanford University Hospital; Kimford Meador, MD – Professor, Neurology & Neurological Sciences, Stanford University
Rationale: The preoperative evaluation for epilepsy surgery involves not only localization of seizure onset but also localization of dysfunction to predict risks of surgical resection. High density electroencephalography (HDEEG) is a noninvasive method which can be used to locate the source of the EEG in a specific brain region with high spatial resolution as well as temporal resolution. In this study, we sought to examine hippocampal function using HDEEG noninvasively to measure desynchronization of HDEEG signals in hippocampi as reflected in changes of total power during resting state vs. memory tasks.
Methods: Signals of HDEEG were collected from eight healthy adult subjects during eyes-closed resting state and during eyes-open recognition memory tasks for faces and words. Each memory task had 100 trials in each of 2 runs including first presentation run (task to detect a rare recurring item) and second run (task to detect new vs old stimuli which occurred with 50/50 chance). HDEEG was collected during eyes-closed resting state (divided into 500ms epochs), eyes-open pre-stimulus (500 ms), and post-stimulus (2000ms segmented into sequential 500 ms epochs). Region of interest analyses were conducted for the hippocampal regions. Total power in 500ms epochs was calculated for both resting state and task data to quantify the changes of power during the memory tasks (Figure 1). ANOVAs were conducted to assess differences across conditions.
Results: The total power of HDEEG signals in hippocampal regions (both left and right sides) during memory tasks showed significant decrease across all 5 time points (pre- and post-stimulus) for both face and word tasks compared to eyes-closed resting (P< 0.01, ANOVA test) (Figure 2). Total power was reduced in all five eyes-open segments and did not differ across eyes-open conditions. Total power between left and right hippocampal regions did not show significant difference across conditions.
Neurophysiology