Abstract
Several neuroimaging studies have examined the effect of different types and combinations of exercises on activation of brain associated with cognitive testing but none of these studies have examined the role of high intensity intermittent exercise (HIIE) in altering cortical activation from simple to complex cognitive tasks. 
 The purpose of this study was to find if HIIE has a role in modulating executive functions related to inhibitory control as expressed by changes in prefrontal cortex (PFC) activation. 
 Materials and methods. 40 healthy adults aged between 18-30 years volunteered for the study. They were randomly divided into HIIE a (n = 20) group and a control (n = 20) group. The HIIE group performed 4*4 min of high intensity exercise on a cycle ergometer with 3 minutes of active recovery at lower intensities between the bouts, whereas the control group performed no exercise. Prefrontal hemodynamics (oxy and deoxy haemoglobin) were assessed using functional near infrared spectroscopy (fNIRS) during the Colour Word Stroop test (CWST) on two sessions: pre-session and post-session (1 week after pre-session).
 Results. The results indicate a significant difference in CWST scores which coincided with a significant difference in hemodynamics of PFC between a congruent and a complex incongruent task in the HIIE group. There was a greater activation of the right frontopolar area, the left ventrolateral prefrontal cortex, and the left frontopolar area during the incongruent task in response to acute HIIE. 
 Conclusion. HIIE plays a role in changing brain activation during more complex interference related tasks.
Highlights
A growing body of literature has reported that exercise has an effect on brain activation during cognitive testing (Hyodo et al, 2012; Chang et al, 2012; Bediz et al, 2016)
The results indicate a significant difference in Colour Word Stroop test (CWST) scores which coincided with a significant difference in hemodynamics of prefrontal cortex (PFC) between a congruent and a complex incongruent task in the high intensity intermittent exercise (HIIE) group
Average reaction time scores showed a significant difference between the scores shown by a significant effect of group (F1, 39 = 20.85, p < 0.001, partial η2 = 0.588), and a significant interaction of group*session in the three areas of pre frontal cortex which are shown in the above figure. (A) showing changes in the hemodynamic variables of right frontopolar area (FPA). (B) showing changes in the hemodynamic variables of left ventrolateral prefrontal cortex (VLPFC). (C) showing changes in the hemodynamic variables of left FPA
Summary
A growing body of literature has reported that exercise has an effect on brain activation during cognitive testing (Hyodo et al, 2012; Chang et al, 2012; Bediz et al, 2016). CWST is a robust test which is used to assess executive functions including processing speed, selective attention and the degree of automaticity (Martinsen et al, 2018). It has two types of stimuli: congruent, testing fluency of reading words and incongruent, testing the ability to inhibit the interference (Scarpina & Tagini, 2017). The latter is a more complex task and needs involvement of more neural substrate (Floden et al, 2011). Acute exercise enhances the activity of prefrontal cortex and involves activation in dorsolateral prefrontal cortex and frontopolar area of prefrontal cortex (Byun et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
