Fig. 2.

Brain regions showing smaller gray matter volume in lonely subjects when compared with non-lonely subjects after controlled for age, sex, MMSE, and total brain volume. a Clusters of smaller gray matter volume in region of the thalamus in subjective cognitive decline group; clusters of smaller rGMV in the region of cerebellar vernal lobules and the left middle occipital gyrus in mild cognitive impairment group. b ROI masks were created for the thalamus, the middle occipital gyrus, and the cerebellar vermal lobules I − V, respectively. Then the gray matter volume of these three regions was extracted for further two-tail t-test controlled for age, sex, MMSE, and total brain volume in each group. *P < 0.05, **P < 0.001