Theory of mind in amnestic mild cognitive impairment: an FMRI study

Theory of Mind (ToM) undergoes changes at the behavioral level in pathological aging (Alzheimer’s disease (AD))\r\nand at the neural level in physiological aging. The aim was to determine if there are changes in ToMin the behavioral and neural\r\ndomains in old subjects with high risk of switching from successful to unsuccessful neurocognitive aging. Patients with amnestic\r\nmild cognitive impairment (aMCI) syndrome were studied, since aMCI was proposed to fill the gap between normal aging and\r\ndementia. Sixteen aMCI patients (mean age 71 years) and fifteen healthy controls (mean age 67 years) with no differences in\r\nage or education were subjected to increasingly complex ToM tasks and to fMRI scanning while performing the Reading the\r\nMind in the Eyes test (RME), which attributes mental states by focusing on eye-gaze. aMCI subjects had worse performances\r\nin two second order false belief tasks, confirming the decay of ToM on the behavioral level. Despite a minor activation of\r\nsome components (posterior end of the superior temporal sulcus and temporal pole) of the ToM neural circuit, no significant\r\ndifferences in the behavioral performances to the RME was found in aMCI compared to controls. Probably the preservation of\r\nthe mirror neuron system (precentral gyrus-BA 6; Broca area - BA 44) and the stronger involvement of frontal areas (middle and\r\nmedial frontal cortex and anterior cingulate cortex) supplemented the decay of part of the mentalizing neural circuit, preserving\r\ntask performance.