Are there theory of mind regions in the brain? A review of the neuroimaging literature

Abstract

There have been many functional imaging studies of the brain basis of theory of mind (ToM) skills, but the findings are heterogeneous and implicate anatomical regions as far apart as orbitofrontal cortex and the inferior parietal lobe. The functional imaging studies are reviewed to determine whether the diverse findings are due to methodological factors. The studies are considered according to the paradigm employed (e.g., stories vs. cartoons and explicit vs. implicit ToM instructions), the mental state(s) investigated, and the language demands of the tasks. Methodological variability does not seem to account for the variation in findings, although this conclusion may partly reflect the relatively small number of studies. Alternatively, several distinct brain regions may be activated during ToM reasoning, forming an integrated functional "network." The imaging findings suggest that there are several "core" regions in the network-including parts of the prefrontal cortex and superior temporal sulcus-while several more "peripheral" regions may contribute to ToM reasoning in a manner contingent on relatively minor aspects of the ToM task.

Figure 1

A comparison of the pattern of brain activity evoked by different ToM tasks. The number of studies implicating each brain region is displayed as a proportion of the number of studies employing each of the following experimental paradigms: mental state terms or word‐pairings [Baron‐Cohen et al.,1994,1999; Mason et al.,2004; Mitchell et al.,2005a], simple questions [Ganis et al.,2003; Kozel et al.,2004; Lee et al.,2002; Spence et al.,2001, stories [Fletcher et al.,1995; Gallagher et al.,2000; Gobbini et al.,2007; Kobayashi et al.,2007; Mitchell,2008; Sabbagh and Taylor,2000; Saxe and Kanwisher,2003; Saxe and Powell,2005; et al., 2001; Young and Saxe,2008], cartoons and other static images [Gallagher et al.,2000; Goel et al.,1995; Lissek et al.,2008; Mitchell et al.,2005b,2006], comic strips, including multi‐frame cartoons involving a choice phase [Brunet et al.,2000; Ciaramidaro et al.,2007; Kobayashi et al.,2007; Sommer et al.,2007; Vollm et al.,2006; Walter et al.,2004], animations and videos [Castelli et al.,2000; German et al.,2004; Gobbini et al.,2007; Grezes et al.,2004a,b; Iacoboni et al.,2005; Mosconi et al.,2005], and interactive paradigms [Calarge et al.,2003; Gallagher et al.,2002; McCabe et al.,2001; Rilling et al.,2004]. The numbers in parentheses refer to the number of studies in that category.

Figure 2

A comparison of the brain regions associated with individual mental states. The number of studies implicating each brain region is displayed as a proportion of the number of studies investigating each type of mental state: General [Baron‐Cohen et al.,1994,1999; Calarge et al.,2003; Castelli et al.,2000; Fletcher et al.,1995; Gallagher et al.,2002; Gobbini et al.,2007; Goel et al.,1995; Mason et al.,2004; McCabe et al.,2001; Mitchell et al.,2002,2005a,b,2006; Rilling et al.,2004; Saxe and Kanwisher,2003; Saxe and Powell,2006; Vogeley et al.,2001], false belief [Gallagher et al.,2000; Gobbini et al.,2007; Grezes et al.,2004b; Kobayashi et al.,2007; Mitchell,2008; Sabbagh and Taylor,2000; Saxe and Kanwisher,2003; Saxe and Powell,2006; Sommer et al.,2007; Young and Saxe,2008], deceit [Ganis et al.,2003; Grezes et al.,2004a; Kozel et al.,2004; Lee et al.,2002; Lissek et al.,2008; Spence et al.,2001], intentions [Brunet et al.,2000; Ciaramidaro et al.,2007; Iacoboni et al.,2005; Mosconi et al.,2005; Vollm et al., 2005; Walter et al.,2004], empathy [Vollm et al.,2006], desire [Saxe and Kanwisher,2003], and pretence [German et al.,2004]. The numbers in parentheses refer to the number of studies in that category.

Figure 3

A comparison of the proportion of verbal and nonverbal tasks that implicate each brain region in ToM. The medial prefrontal and orbitofrontal regions are the most consistently activated region, regardless of whether or not the task is verbal. The results for the verbal and nonverbal tasks are included separately for Gallagher et al. [2000], Gobbini et al. [2007], and Kobayashi et al. [2007]. The numbers in parentheses refer to the number of studies in that category.