The physiological origin of task-evoked systemic artefacts in functional near infrared spectroscopy

• DOI: 10.1016/j.neuroimage.2012.02.074
• Publication Date: 2012-03-09T12:21:24Z
• Authors: Evgeniya Kirilina; Alexander Jelzow; Angela Heine; Michael Niessing; Heidrun Wabnitz; Rüdiger Brühl; Bernd Ittermann; Arthur M. Jacobs; Ilias Tachtsidis
• Keywords: Functional near-infrared spectroscopy; Communication noise

A major methodological challenge of functional near-infrared spectroscopy (fNIRS) is its high sensitivity to haemodynamic fluctuations in the scalp. Superficial contribute on one hand physiological noise fNIRS, impairing signal-to-noise ratio, and may other be erroneously attributed cerebral changes, leading false positives fNIRS experiments. Here we explore localisation, time course origin task-evoked superficial signals present a method separate them from cortical signals. We used complementary fMRI, MR-angiography peripheral measurements (blood pressure, heart rate, skin conductance blood flow) study activation frontal lobe during continuous performance task. The General Linear Model (GLM) was applied analyse data, which included an additional predictor account for systemic changes skin. found that volume strongly depends cognitive state sources are co-localized with veins draining Task-evoked artefacts were mainly observed concentration oxygenated haemoglobin could effectively separated by GLM analysis. Based temporal correlation fMRI conclude artefact sympathetic arterial vasoconstriction followed decrease venous volume. Since outflow accompany almost any emotional process, expect scalp vessel wide range settings neurocognitive research. Therefore careful separation originating activated brain necessary precondition unbiased maps.