PhD Scientific Days 2017

Oral Presentations: Neurosciences

Investigating the impact of cognitive load on network measures in the prefrontal cortex - a functional near-infrared spectroscopic (fNIRS) study

Előadó neve

TÖRÖLHETŐRacz, Frigyes Samuel

Előadó munkahelye

Department of Physiology, Semmelweis University

Előadó telefonszáma

06207703934

Előadó e-mail címe

raczfrigyessamuel@gmail.com

Az előadás címe

Investigating the impact of cognitive load on network measures in the prefrontal cortex - a functional near-infrared spectroscopic (fNIRS) study

Szerző(k) neve és munkahelye

1 Frigyes Samuel Racz, , Department of Physiology, Semmelweis University, Budapest
2 Peter Mukli, MD, Department of Physiology, Semmelweis University, Budapest

Szekció

Oral Presentations: Neurosciences

Data of the presenter

Doctoral School: Basic Medicine
Program: The Mechanisms of Normal and Pathologic Functions of the Circulatory System
Supervisor: Andras Eke, MD, PhD
E-mail: raczfrigyessamuel@gmail.com, racz.frigyes@med.semmelweis-univ.hu

Text of the abstract

Introduction: Neural activity produces a local hemodynamic response through neurovascular coupling, that can be detected by functional near infrared spectroscopy (fNIRS). From the fNIRS data the functional networks of the brain can be reconstructed and described quantitatively through network metrics.
Aims: Our goal was to investigate the impact of cognitive load on functional connectivity in the prefrontal cortex (PFC).
Methods: Healthy adults (6 males, 6 females, 23±2 yrs. of age) were recruited for the study and assigned to control and test groups. We performed fNIRS measurements on 16 regions of interest of the PFC at a sampling frequency of 3 Hz. Measurements were performed in resting state (control) and during pattern recognition (test). Increased neural activity was captured as the running corss-correlation coefficient (rHb) of the hemoglobin compartments. Hemoglobin fluctuations related to neural activity (HbN) were separated from the raw NIRS-data. Graph representations of functional connections were derived from cross-correlation matrices calculated from HbN signals. The resulting functional networks were thresholded in a step-wise manner. The following network metrics were calculated: connection density (D) for the overall wiring cost, clustering coefficient (C) for functional segregation and the average inverse shortest path length (E) for functional integration. Groups were compared with two-sample t tests.
Results: In the test group, rHb decreased during stimulation indicating increased neuronal activity. When compared to the control group, test D, C and E values were significantly higher for most of the threshold values.
Conclusion: Our pattern recognition test proved to offer a new stimulation paradigm of the PFC. Our results showed that cognitive load increases the functional connectivity in the PFC. Our NIRS-based imaging techniqe and graph theoretical analysis proved to be an effective approach to characterzie cognition quantitatively, thus can be applied in further studies investigating cognitive performance in different conditions.

Kind

Szabad

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

1119

Authors (legacy)

1 Frigyes Samuel Racz, , Department of Physiology, Semmelweis University, Budapest
2 Peter Mukli, MD, Department of Physiology, Semmelweis University, Budapest