Correlation analysis showed ALFF values in insular cortex is related to corneal chemical sensitivity
To further examine the contribution of ALFF changed brain areas to chronic corneal pain, we conducted a correlation analysis between ALFF values of S2, AID, AIP, AuV, TeA, Ect, and eye blinking times after chemical application. We found there was a significant correlation between the ALFF values of AID and AIP, which belong to the insular cortex, and eye blinking times after capsaicin (Figure 5b, P< 0.001; Figure5c, p=0.014) and menthol application (Figure 5h, P< 0.001; Figure 5i, P< 0.001) according to the Pearson correlation analysis. No correlation was observed in other brain regions at the P< 0.05 level. Therefore, we speculated insular cortex might play an essential role in chronic corneal pain.