Resting-state BOLD oscillation frequency predicts vigilance task performance at both normal and high environmental...

Area of Science:

• Neuroscience
• Environmental Physiology
• Cognitive Science

Background:

• Hyperthermia can impair cognitive functions, including vigilance.
• Environmental heat stress may affect cerebral hemodynamic regulation and neural oscillations.

Purpose of the Study:

• To investigate the impact of hyperthermia on vigilance functions and cerebral hemodynamics.
• To explore the relationship between brain activity rhythms and reaction times under thermal stress.

Main Methods:

• Acquired resting-state BOLD and cerebral blood flow (CBF) data from 15 participants under normothermic and hyperthermic conditions (50°C/25°C).
• Utilized frequency component analysis to quantify BOLD oscillation frequencies and correlated them with psychomotor vigilance task (PVT) reaction times (RTs).
• Compared changes in BOLD frequency and CBF between thermal conditions and analyzed spatial correlations.

Main Results:

• RTs correlated positively with BOLD frequency in the default mode network (DMN) and negatively in the sensorimotor network (SMN).
• Hyperthermia increased BOLD frequency in the thalamus and medial prefrontal cortex, correlating with slower RTs.
• Hyperthermia decreased BOLD frequency and CBF in the SMN, while increasing CBF in the thalamus and posterior cingulate.

Conclusions:

• Hyperthermia may impair cognitive performance by disrupting resting-state cerebral blood flow and BOLD rhythms.
• Neural mechanisms underlying hyperthermia-induced cognitive deficits may involve the interplay between thermoregulation and vigilance networks (SMN, DMN).