Beyond aphasia: Altered EEG connectivity in Broca's patients during working memory task

Area of Science:

• Neuroscience
• Cognitive Science
• Neurolinguistics

Background:

• Broca's region and adjacent cortical areas are implicated in working memory (WM) functions.
• Synchronized brain oscillations are electrophysiological markers of WM processes.
• The impact of Broca's aphasia on functional WM networks remains largely unexplored.

Purpose of the Study:

• To investigate the effects of stroke-induced Broca's aphasia on synchronized functional WM networks.
• To identify alterations in brain network activity during verbal WM tasks in patients with Broca's aphasia.

Main Methods:

• Utilized high-density electroencephalography (EEG) and coherence analysis.
• Mapped WM networks in ten Broca's aphasia patients and ten healthy controls.
• Assessed network activity during a verbal WM task.

Main Results:

• Broca's aphasia significantly alters two distinct WM networks: theta and gamma functional networks.
• Theta network alterations suggest a disrupted balance between task-positive and irrelevant networks.
• Complete disintegration of the left fronto-centroparietal gamma network observed in patients, potentially indicating damage to the phonological loop.

Conclusions:

• Stroke-induced Broca's aphasia alters both executive (theta) and phonological (gamma) WM networks.
• The findings provide insights into the neural underpinnings of WM deficits in aphasia.
• This research highlights the critical role of Broca's area in maintaining integrated functional WM networks.