Furthermore, the increased FC due to the compensatory mechanism seems to cause a decline in other FC. For example, the angular gyrus showed increased FC between the bilateral hippocampus and hippocampal gyrus in the DMN, while decreased FC was observed between the bilateral superior/middle frontal and thalamus in the SN and ECN. These results suggest that the functional allocation of the angular gyrus was increased to compensate the function of the damaged hippocampus, resulting in a relatively reduced load of functions synchronized with the structurally unimpaired areas. This result indicates that structural damage, which is shown mainly in hippocampus and mPFC, can cause functional changes in the triple networks overall by directly or indirectly affecting the function of other areas without structural impairment. The various clinical characteristics associated with the impairment of triple networks in alcoholics may be due to structural damage in just a few areas in these networks, suggesting that the key node of these altered function is the hippocampus.
