Abstract
Activation of the cerebral prefrontal cortex (PFC) has been reported to play important roles in neurocognitive functions, such as learning and cognitive performance. An increasing number of human studies using near-infrared spectroscopy (NIRS) have extensively investigated the activation of the PFC associated with cognitive tasks. However, the association of cold stimulus with neurocognitive function and PFC activation has not been elucidated using NIRS. We examined the effect of cold stimulus on the cheeks on the activation of the cerebral PFC using NIRS in 18 adult male participants. We also examined the percent change in cognitive performance related to the activation of the PFC in the Stroop cognitive test with and without cold stimulus. Cold stimulus on the cheeks significantly increased blood flow bilaterally in the PFC, including the left dorsolateral regions. An increase in the cognitive performance on the Stroop cognitive test was significantly associated with the cold stimulus, which coincided with enhanced activation of the left dorsolateral region of the PFC. Therefore, cold stimulus on the cheeks may lead to enhanced Stroop cognitive performance, accompanied by the activation of the left dorsolateral region of the PFC. Cold stimuli may be applied on the cheeks to improve cognitive performance by enhancing the PFC activities via trigeminal nerve stimulation in the daily life. Furthermore, the findings of the present study provide insights for practical, non-pharmaceutical interventions using cold stimuli for cognitive enhancement in the elderly.