Affective and Cognitive Theory of Mind Networks in Young Healthy Individuals
Elisa Canu1, Chiara Tripodi1, Anna Marangon1, Veronica Castelnovo1, Silvia Basaia1, Edoardo Spinelli2, Federica Agosta2, Massimo Filippi3
1Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 2Neuroimaging Research Unit, Division of Neuroscience; and Neurology Unit, 3Neuroimaging Research Unit, Division of Neuroscience; Neurology Unit; Neurorehabilitation Unit; and Neurophysiology Service, IRCCS San Raffaele Scientific Institute; and Vita-Salute San Raffaele University
Objective:
To identify core regions specifically and differentially involved in the two networks mediating cognitive and affective Theory of Mind (ToM) in young healthy individuals.
Background:
ToM refers to the ability to infer others’ beliefs (cognitive ToM) and to understand others’ emotions (affective ToM). Despite the identification of several brain areas related to these skills, no definitive consensus has been reached as regards the underlying brain networks, and only a few neuroimaging studies investigated functional connectivity (FC) in non-clinical settings, especially in healthy adults at a young age, when brain circuits are still not affected by aging.
Design/Methods:
50 healthy subjects (23 females; age: 25±3) underwent resting-state functional MRI (RS-fMRI) and a neuropsychological evaluation. Based on a recent metanalysis on healthy middle-aged adults, two regions of interest were created as main nodes for affective and cognitive ToM, respectively: left medial prefrontal cortex (lmPFC) and right supramarginal gyrus (rSMG). A seed-based RS-FC analysis was performed between the two nodes, separately, and the rest of the brain.
Results:
We observed that the lmPFC FC included an anterior and ventral network encompassing left supplementary motor area, left temporal pole, and, bilaterally, precentral gyrus and insula. On the other hand, the rSMG FC encompassed a more posterior and dorsolateral network including right precuneus, left inferior parietal gyrus and middle occipital gyrus, bilateral angular gyrus, and cerebellum crus I and II. Overlapping brain areas shared by both networks were inferior frontal gyrus, middle temporal gyrus, temporoparietal junction, and anterior cingulate cortex bilaterally.
Conclusions:
In line with existing literature, seed-based RS-FC analysis revealed two distinct, but interdependent ToM systems. These findings provide a model to evaluate the integrity of such networks also in a clinical scenario and may serve to compare network deterioration across different neurodegenerative diseases, preferentially in the Frontotemporal Lobar Degeneration Spectrum of disorders.