2.2.1. Neural bases of mentalizing

We started our survey of the relevant literature by searching for “ToM fMRI” and “mentalizing fMRI” on Pubmed (https://www.ncbi.nlm.nih.gov/pubmed/). After duplicate removal, a preliminary pool of 1,092 studies was first screened by title, and then by abstract. We retained only those studies fulfilling the following selection criteria (see Figure S1 for details on the procedure for study selection):

studies written in English language;

empirical fMRI studies, while excluding review and meta‐analysis studies and those employing other techniques, to ensure comparable spatial and temporal resolution;

studies reporting whole‐brain activation coordinates, rather than regions of interest (ROIs) or results of small volume correction (SVC). Studies based on ROIs or SVC should be excluded because a prerequisite for fMRI meta‐analyses is that convergence across experiments is tested against a nullhypothesis of random spatial associations across the entire brain, under the assumption that each voxel has the same a priori chance of being activated (Eickhoff, Bzdok, Laird, Kurth, & Fox, 2012; Muller et al., 2018);

studies including drug‐free and nonclinical participants, to prevent possible differences in brain activity associated with pharmacological manipulations or neuro‐psychiatric diseases other than those under investigation;

studies with adult subjects (age range: 18–60 years);

studies requiring the understanding of others' beliefs, emotional states, and intentions, while excluding those aimed to induce an affective sharing and brain activity interpreted in terms of empathic resonance;

studies requiring participants to represent others' mental states by adopting an intentional stance toward others, that is, by understanding their thoughts, emotional states, desires, intentions, and future actions in terms of abstract inferences detached from a sensory stimulation. Namely, we selected contrasts that were specifically aimed to elicit brain activations interpreted by the authors in terms of “mentalizing or theory of mind network” associated with the representation or attribution of mental states, that is: a) inferences on mental states or intentions > inferences on physic or perceptual aspects, or on literal meanings other than mental states; b) attribution of emotional mental states > gender inferences (based on Baron‐Cohen, Wheelwright, Hill, Raste, and Plumb's (2001) “Reading the mind in the eyes” task); c) human interactions > computer interactions, during interactive games.

Within the studies fulfilling these criteria, we retained only the contrasts between conditions differing in terms of the requirement to represent mental states.

Starting from an initial screening of 1,092 titles and abstracts, 622 papers deemed as potentially relevant were fully reviewed based on the aforementioned selection criteria (see Figure S1). We thus excluded: 134 review or meta‐analysis articles; 43 studies employing techniques other than fMRI; 30 studies using ROIs or SVC; 2 studies explicitly focused on empathic processing; 41 studies focused on children or aging populations; 33 studies not reporting all the required information; 189 studies focused on clinical populations and 45 studies that did not focus on mentalizing.

We included studies fulfilling the above criteria regardless of: (a) sensory modality (e.g., visual or auditory); (b) experimental paradigm (e.g., comprehension or attentional tasks); (c) stimulus type (e.g., videos, photos, and verbal materials). Our aim was indeed to pool across different experimental paradigms to ensure both generalizability and consistency of results, within the requirement of mentalizing inherent in our research question (Radua & Mataix‐Cols, 2012). This selection phase resulted in 105 studies fulfilling our criteria.

We then expanded our search for other potentially relevant studies by carefully examining both the studies quoting, and those quoted by, each of these papers, alongside previously published meta‐analyses on the neural bases of mentalizing (Bzdok et al., 2012; Molenberghs et al., 2016; Spreng, Mar, & Kim, 2009; van Veluw and Chance, 2014). This second phase highlighted seven further studies fitting our search criteria. Overall, this procedure led to include in the ALE meta‐analysis 112 previously published studies (see Table S1), resulting from 113 experiments (individual comparisons reported) with 2,295 subjects and 1,696 activation foci. Tasks were classified as “affective” if they required participants to infer emotional mental states, and “cognitive” if they involved understanding beliefs, intentions or goals. In total, 412 activation foci from 26 experiments were ascribed to affective mentalizing, and 1,272 activation foci from 93 experiments to cognitive mentalizing (see Table S1).