LAUSR

HighlightsWe investigated the ReHo and functional connectivity during hyperthermia.Participants had decreased regional neural activity in the frontal‐occipital cortex.The ReHo alteration in left dorsolateral prefrontal cortex was correlated with executive control effect.Hyperthermia could cause brain activity disruptions at the level of local ReHo and long‐range functional connectivity. Abstract Passive hyperthermia would impair wide‐domain cognitive performances (e.g. attention, working memory), which may involve abnormal regional and long‐range neural activity. Combining the regional homogeneity (ReHo) and seed‐based functional connectivity analysis, this study investigated the regional and long‐range neural synchronization abnormality during passive hyperthermia. We acquired the resting‐state blood oxygenation level dependent (BOLD) data from twenty‐three healthy male participants in two simulated thermal conditions: normothermic condition (NC) with temperature at 25°C for 1 h and hyperthermic condition (HC) with temperature at 50°C for 1 h. After scanning, participants were asked to perform an attention network test (ANT). Relative to NC participants, the participants in HC group exhibited decreased regional neural synchronization in the frontal‐occipital cortex, specifically in the left opercular part of inferior frontal gyrus/insula, bilateral middle occipital gyrus, and posterior cingulate cortex/precuneus, but increased one in the left dorsal superior/middle frontal gyrus. Using these significantly differed ReHo clusters as seeds, we further performed functional connectivity analysis and found aberrant long‐range neural synchronization in the orbital medial frontal cortex, temporal‐parietal junction areas. Further neurobehavioral correlation analysis showed significant positive correlation between the regional ReHo alteration in left dorsolateral superior/middle frontal gyrus and executive control effect. Additionally, the functional connectivity of the orbital medial frontal cortex with the seeds “left superior/middle frontal gyrus” and “posterior cingulate cortex/precuneus” were negatively correlated with the increase of rectal temperature. In current study, the participants showed hyperthermia‐induced brain activity disruptions, appearing as altered local ReHo and long‐range functional connectivity, which might help understand the relationship between neuronal and circuit activities and physiological thermal sensation and regulation as well as behavioral changes.