The purpose of this experiment was to measure changes in cerebral blood flow in the prefrontal cortex during personality self-rating and to examine intra-individual variability during self-rating and the characteristics of cerebral blood flow by conditions.
The participants were 61 university students (29 men and 31 women, missing value1) and was conducted in May-December2023. Participants were performed Big Five inventory before we used NIRS-based Hemoencephalography to measure frontal cerebral blood flow under six self-rating conditions: three PC conditions, two questionnaire conditions, and one eyes-closed condition as an individual baseline. For each participant, the Means and SD of all intervals were standardized within each individual, with a mean of 100 and a standard deviation of 15 for each condition.
We calculated the Means and SD to compare frontal cerebral blood flow for each experimental participant and the six conditions. The ANOVA results showed that there was a significant difference between participants(F(60,363)=134.9,p<.01), so it was revealed that there were individual differences in frontal cerebral blood flow during self-rating. When examining the Means for each condition of the participants, it was shown that all participants had different baseline values for frontal cerebral blood flow, and that each task condition fluctuated based on this value. As there was a significant difference for conditions(F(5,363)=6.84,p<.01), it suggested that participants were able to discriminate between the self-rating tasks. When comparing the Means across task conditions, the Means cerebral blood flow was higher in the questionnaire condition than in the PC condition, it suggested that questionnaires using paper and pen enable greater concentration self-rating than PC rating. These results supported previous research (Sato & Matsuda, 2019), it showed that self-rating tasks result in individual differences in frontal cerebral blood flow and that there are differences depending on the rating tasks.