The Association Between Alexithymia and Functional Connectivity of Dorsal Anterior Cingulate Cortex

The aim of this study was to examine the association between alexithymia components (difficulty identifying feelings (DIF), difficulty describing feelings (DDF), and externally-oriented thinking (EOT)) and resting state functional connectivity (FC) of left and right dorsal anterior cingulate cortex (dACC) in an fMRI study to investigate the underlying neural mechanisms of different features of alexithymia.Method Our dataset was obtained from Otto von Guericke University [1]. T1-weighted structural images and fMRI images of 32 healthy subjects were analyzed. Images had been acquired by a 7T scanner. Alexithymia scores had been studied by Toronto alexithymia scale (TAS-20) [2]. Preprocessing was performed by DPARSF toolbox. Regression analysis with TAS subscale were conducted for each seed (left dACC and right dACC) using SPM12 (corrected FDR p-value<0.05).Results Results showed that DDF had a positive association with FC of left dACC to right frontal pole (FP) and left superior frontal gyrus (SFG). DDF had a positive association with FC of right dACC to right FP, left SFG, right superior temporal gyrus (STG), and left posterior temporal fusiform cortex (pTFC). There was a significant positive correlation between DIF and FC of left dACC to right FP. There was no significant association between EOT and FC of any of the seeds. Conclusions Since superior frontal gyrus processes the language, the association between DIF and FC of left dACC to right SFG shows that inability to differentiate emotions is linked to limited capacity for language processing. FP processes higher-order relations between mental representations. The correlation between DDF and FC of right dACC to left STG approves that one characteristic of alexithymia is difficulty in understanding the meaning of emotional words. Another aspect of insomnia is difficulty in recognition of facial expressions (reflected in the correlation between DDF and FC of right dACC to left pTFC).