Statistical Analysis

The statistical analysis was performed using IBM SPSS Statistics (SPSS Inc., Chicago, Illinois, USA, Version 23.0). The experimental data of each group were expressed as x ± s. The chi-square test was used for sex between groups, and an independent sample t-test was used to compare age and education level. For the bilateral test, p < 0.05 was considered statistically significant.

We used to represent the accuracy of facial expression recognition – the measurement value of discriminate ability – which follows the signal detection theory and uses the hit rate and false positive rate to estimate recognition ability (Macmillan and Creelman, 2005). Raw scores for each of the 10 MCCB tests were transformed into T-scores. First, we calculated a series of t-tests to assess differences between patient groups and controls regarding emotion recognition performance and cognitive function variables. Second, we assessed the bivariate two-tailed Pearson’s correlations between facial expression recognition and cognitive scores in patients with depression. Finally, we used Pearson’s correlation to analyze the relationship between facial expressions that were significantly associated with cognitive function scores and various cognitive domains.