Physical Stress Attenuates Cognitive Inhibition: An fNIRS Examination

Abstract

This study aimed to assess the haemodynamics in the prefrontal cortex (PFC) and salivary α-amylase (sAA) response during acute physical stress. Acute stress was induced using the cold pressor task (CPT). The haemodynamics in the prefrontal cortex was measured using functional near-infrared spectroscopy (fNIRS). The Stroop test was performed and the sAA levels were measured before and after the task. The accuracy rate (%) of the Stroop test decreased significantly in the stress group (t = 2.80, p = 0.008) but not the control group (t = −1.05, p = 0.298). The results showed that oxyHb activation in the mid-left and mid-right regions of PFC after the CPT. The sAA levels significantly increased during and after the CPT in the stress group (U/ml, 2527.58 ± 437.54, mean ± SD, n = 26) but not the control group (U/ml, 1506.92 ± 291.05, n = 23). Our data showed that the acute stress exposure attenuated cognitive inhibition, which may be due to changes of scalp blood flow and/or cerebral haemodynamics near the mid-left PFC and mid-right PFC following acute stress.