Hemodynamic Brain Responses During Working Memory Load Processing in Aphasia

EasyChair Preprint no. 6521

Abstract

Several neuroimaging technologies have been used with post-stroke individuals with aphasia (IWA) to understand their neurobehavioral performance and neurological markers associated with language and cognitive difficulties. Very few studies have used functional near-infrared spectroscopy (fNIRS) technology to understand brain activations and hemodynamic markers of behavior in aphasia. This study investigated the feasibility of a fNIRS system in measuring hemodynamic responses in IWA on cognitive tasks of varying mental workload. Pilot data from four IWA with a history of unilateral stroke without any other coexisting neurological or psychological disorders are presented here. All participants completed a computer-delivered working memory (n-back) task that varied across two workload conditions:1- back (low load) and 2-back (high load). Cortical hemodynamics of the prefrontal cortex was measured using an 18-channel optode band. Relative changes in oxygen concentration during task in comparison to the initial rest period was calculated. Hemodynamic responses due to workload induced by n-back tasks were discriminated from the resting state. Several interesting findings were noted- differential pattern of oxygen consumption in the brain were observed between 1- and 2-back tasks, oxygenated hemoglobin concentration was high for the 2-back (high) load condition, and deoxygenated hemoglobin concentration was more for the 1-back (low) load condition. Overall, our data support the feasibility of fNIRS to detect mental workload in IWA. These findings provide a foundation for future exploration of hemodynamic activation during language and cognitive processing in aphasia.

Keyphrases: aphasia, fNIRS, working memory, Workload

@Booklet{EasyChair:6521,
  author = {Bijoyaa Mohapatra},
  title = {Hemodynamic Brain Responses During Working Memory Load Processing in Aphasia},
  howpublished = {EasyChair Preprint no. 6521},

  year = {EasyChair, 2021}}