Abstracts

Dynamic Reconfiguration of Functional Connectivity in Brain Lateralization During Face and Word Tasks Using High Density Electroencephalography (HDEEG)

Abstract number : 1.181
Submission category : 3. Neurophysiology / 3G. Computational Analysis & Modeling of EEG
Year : 2023
Submission ID : 252
Source : www.aesnet.org
Presentation date : 12/2/2023 12:00:00 AM
Published date :

Authors :
Presenting Author: Hua Huang, PhD – Stanford University

Adam Fogarty, Bachelor – Stanford University Hospital; Jordan Seliger, Master – Stanford University; Kimford Meador, MD – Stanford University

Rationale: Cognitive processing involves not only spatial activations of certain brain regions and connectivity between brain regions but also dynamic changes of involved brain regions due to temporal changes in interactions during the cognitive tasks. High density electroencephalography (HDEEG) is a noninvasive measure which can be used to estimate the source of the electrical signals in a certain brain region with reasonable spatial resolution as well as high temporal resolution. In this study, we examined cognitive function using HDEEG to measure brain network dynamic changes between brain regions as indicated in changes of connectivity during resting state, pre stimulus, and post stimulus of memory tasks.

Methods: The HDEEG signals were collected from eight healthy adult subjects during eyes-closed resting state and eyes-open memory tasks for faces and words. Each memory task had 200 trials segmented into four 50 trial blocks. During the first two blocks, the task was to detect rare recurring stimuli (five repeated). During the third and fourth blocks, the task was to detect new versus previously presented stimuli which occurred with 50/50 chance. HDEEG signals were acquired during a separate eyes-closed resting state, eyes-open pre stimulus (100ms), and post stimulus (2000ms segmented into sequential 100ms epochs). Region of interest analyses were conducted for 36 brain regions involved in memory activities. Connectivity between brain regions in each 100ms epoch was calculated for resting state, pre stimulus, and post stimulus (with 50ms sliding windows for post stimulus) of task data to quantify the dynamic changes of connectivity during the memory tasks (see Figure 1). T tests were conducted to assess significant differences across conditions.

Results: The dynamic changes of connectivity pattern within 450ms post stimulus were identified for face and word memory tasks in each 100ms with significance (P< 0.05) compared to pre stimulus. Specific patterns of brain lateralization (difference in left and right hemispheres) for face and word recognitions were characterized and the brain regions involved in face and word tasks in each 100ms epoch were marked (see Figure 2). The significant difference between face and word tasks was identified with P< 0.05 for each 100ms time window (see Figure 2).
Neurophysiology