Objective:
This project aims to identify the neural mechanism of attention shift underlying cognitive and social dysfunction in attention disorders such as ADHD and Autism and executive dysfunction in Parkinson’s disease.
Background:
The neural mechanism of attention shift in humans is less studied due to limited access to direct prefrontal and cingulate cortex electrophysiological recordings. Functional MRI studies revealed two distinguished attention networks for goal-driven and stimulus-driven attention shifts: the dorsal (DAN) and the ventral attention network (VAN.)
Design/Methods:
I use intracranial EEG (iEEG) with stereotactic depth probes (sEEG) in presurgical epilepsy patients to measures local brain activity in high-frequency broadband activity in 80-180 Hz. I use this technique to study the temporal dynamics of the mesial, lateral prefrontal, and cingulate cortices in attention shifts. For behavioral analysis, the proportion of correct and incorrect trials relative to the number of all trials is computed for each subject. The correct trials are calculated as the total number of hits (HIT, responding to the relevant target) and Correct Rejection (CR, not responding to the irrelevant target). The incorrect trials consist of false alarms (FA, responding to the irrelevant target), misses (MISS, not responding to the relevant target), and random responses.
Results:
1) Correct-response rate decreased in first trials after the cue, Post-Cue-Stim, compared to a trial before the cue, Pre-cue-Stim, and second trial after the cue, Post-Cue-2nd-Stim. 2) HFB activity for the trials after the cue, Post-Cue-Stim, traced decreases for an electrode in DMN. 3) The activity of DAN in Post-Cue-Stim trials is increased compared to the Pre-cue-Stim and Post-Cue-2nd-Stim trials, indicating the effect of attention shift compared to sustained attention.
Conclusions:
The attention networks (DAN and VAN) and DMN have opposing activation patterns during attention and resting state.