Changes in Cortical Oxyhaemoglobin Signal During Low-Intensity Cycle Ergometer Activity: A Near-Infrared Spectroscopy Study

Abstract

Near-infrared spectroscopy (NIRS) is a widely used non-invasive method for measuring human brain activation based on the cerebral hemodynamic response during gross motor tasks. However, systemic changes can influence measured NIRS signals. We aimed to determine and compare time-dependent changes in NIRS signal, skin blood flow (SBF), and mean arterial pressure (MAP) during low-intensity, constant, dynamic exercise. Nine healthy volunteers (22.1±1.7 years, 3 women) participated in this study. After a 4-min pre-exercise rest and a 4-min warm-up, they exercised on a bicycle ergometer at workloads corresponding to 30% VO2 peak for 20 min. An 8-min rest period followed the exercise. Cortical oxyhaemoglobin signals (O2Hb) were recorded while subjects performed the exercise, using an NIRS system. Changes in SBF and MAP were also measured during exercise. O2Hb increased to 0.019 mM cm over 6 min of exercise, decreased slightly from 13 min towards the end of the exercise. SBF continued to increase over 16 min of the exercise period and thereafter decreased till the end of measurement. MAP fluctuated from -1.0 to 7.1 mmHg during the exercise. Pearson's correlation coefficients between SBF and O2Hb, and MAP and O2Hb differed in each time phase, from -0.365 to 0.713. During low-intensity, constant, dynamic exercise, the profile of changes in measurements of O2Hb, SBF, and MAP differed. These results suggested that it is necessary to confirm the relationship between O2Hb and systemic factors during motor tasks in order to detect cortical activation during gross motor tasks.

Applications of Functional Near-Infrared Spectroscopy (fNIRS) Neuroimaging in Exercise–Cognition Science: A Systematic, Methodology-Focused Review

“…Since a vast amount of literature shows that fNIRS is vulnerable to physiological noise, such as blood flow changes in the extracerebral compartment [30,70,210,211,241,242,243,244,245,246,247,248,249,250,251,252], which may cause false positive results [69], these artefacts should be reduced. A powerful tool to reduce extracerebral physiological noise is to use a combination of NIRS light channels with a short source–detector separation and with a long source–detector separation [61,152,210,211,253,254,255,256,257,258,259,260].…”

“…In general, a higher activity of cortical structures (during cognitive testing) was observed after the cessation of an acute bout of physical activity (e.g., aerobic activities such as cycling) when compared to the cortical activity (i) measured before being physically active, or (ii) in a control condition (e.g., sitting). Since fNIRS signals are substantially affected by systemic physiological artefacts [70,71,72,241,242,247,248,249,251,252,271], it could be assumed that effects of physical activity on measured cortical oxygenation levels (after being physically active) are mainly caused by the systemic physiological artefacts (e.g., higher heart rate or superficial blood flow). Indeed, the findings of a methodological study suggest that fNIRS signals after the cessation of ten minutes of cycling are influenced up to approximately eight minutes by systemic physiological artefacts (depending on the intensity of the physical activity) [87].…”

Prefrontal Cortex Oxygenation During Endurance Performance: A Systematic Review of Functional Near-Infrared Spectroscopy Studies

“…Positioning of the optodes and receivers with the associated inter-optode distances (IODs) varies and is described in Tables 5A , B . Nineteen studies used the international EEG 10-20 system with optode placements over the prefrontal lobe at Fp1,Fp2, Fp3, and/or Fp4 position ( Rupp and Perrey, 2008 ; Timinkul et al, 2008 ; Billaut et al, 2010 ; Keramidas et al, 2011 ; Rupp et al, 2013 ; Giles et al, 2014 ; Oussaidene et al, 2015 ; Santos-Concejero et al, 2015 , 2017 ; Pires et al, 2016 ; Tempest and Parfitt, 2016 ; Tsubaki et al, 2016 , 2018 , 2020 ; Takehara et al, 2017 ; Tempest et al, 2017 ; Asahara and Matsukawa, 2018 ; Ohyanagi et al, 2018 ; Stevens et al, 2018 ) pecifying this location as ± 3 cm from the midline, just above the supra-orbital ridge ( Bhambhani et al, 2007 ; Miyazawa et al, 2013 ). Jung et al (2015) used Broadman area 10, Montreal Neurophysiological Institute (MNI) coordinates [( x / y / z ) −40, 50, 0], two studies performed a three-dimensional T1-weighted MRI scan, marking the optode location for the left and right PFC ( Suzuki et al, 2004 ; Fumoto et al, 2010 ), and finally, two studies placed the device on the participants’ forehead without specifying the exact location of the optode placement ( Shibuya et al, 2004 ; Kounalakis and Geladas, 2012 ).…”

“…nRCT, non-randomized controlled trial; nRnCT, non-randomized non-controlled trial; RCT, randomized controlled trial. -Concejero et al, 2015-Concejero et al, , 2017Pires et al, 2016;Tempest and Parfitt, 2016;Tsubaki et al, 2016Tsubaki et al, , 2018Tsubaki et al, , 2020Takehara et al, 2017;Tempest et al, 2017;Asahara and Matsukawa, 2018;Ohyanagi et al, 2018;Stevens et al, 2018) pecifying this location as ± 3 cm from the midline, just above the supra-orbital ridge (Bhambhani et al, 2007;Miyazawa et al, 2013). Jung et al (2015) used Broadman area 10, Montreal Neurophysiological Institute (MNI) coordinates [(x/y/z) −40, 50, 0], two studies performed a three-dimensional T1-weighted MRI scan, marking the optode location for the left and right PFC (Suzuki et al, 2004;Fumoto et al, 2010), and finally, two studies placed the device on the participants' forehead without specifying the exact location of the optode placement (Shibuya et al, 2004;Kounalakis and Geladas, 2012).…”

Sex Differences in the Oxygenation of the Left and Right Prefrontal Cortex during Moderate-Intensity Exercise

“…NIRS measures the change in the concentration of oxygenated hemoglobin (O 2 Hb) and deoxygenated hemoglobin (HHb) caused by cerebral blood flow responses, coupled with nerve activity [ 38 ], with an increase in O 2 Hb reflecting an increase in the nerve activity in brain parenchyma [ 39 ]. NIRS measurements are robust, providing reliable measures even during unrestrained activities, such as running and leg-cycle ergometer pedaling [ 40 , 41 ]. As such, the purpose of our study was to investigate sex-specific differences in PFC oxygenation during moderate-intensity AE.…”