Near infrared spectroscopy study on prefrontal cortex using verbal fluency test

• Main Author: Lau, Janet.
• Other Authors: Lee Kijoon
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/54560
• Institution: Nanyang Technological University

Near Infrared Spectroscopy (NIRS) has in recent years become a popular technique to evaluate cerebral hemodynamics and oxygenation changes of the brain via cognitive task study. NIRS technology utilizes the different light absorption capability of chromophores to monitor blood volume, oxyhemoglobin and deoxyhemoglobin changes. This also allows one to determine positions of the brain which are activated with various tasks. In this report, the author sought to prove the correlation of hemodynamic signal with prefrontal cortex brain activation with cognitive tasks given. This is done by experiment and results analysis. It was found that this hypothesis was indeed true and reliable because the results modeled against a predicted behavior of oxygenation in the brain in course of experiment were found to be corresponding closely. The left prefrontal cortex was found to be dominant in activation during verbal fluency. On top of that, increase of hemodynamic signal also varied with difficulty level of task given. Experimental results were also proven reliable by previous literature and studies. This permits a firm proof of the instrument trustworthiness and provided understanding of how cognitive tasks affect oxygenation of the brain. Subsequently, this validation was valuable for future and more complex experiments like Stroop tasks. However, more studies could be conducted in future to investigate the problems which caused anomalous data yielded from contact problems.