Theory of mind abilities predict grey matter volume in childhood

• In Event: Poster Session 08
  In Poster Session: PS 08 Topic - Biological Processes: Neuroscience and Genetics

Abstract

Defined as the ability to attribute mental states to oneself and others, theory of mind (ToM) plays a crucial role in social adjustment (e.g., Caputi et al., 2012). A growing literature in the field of social neurosciences suggests that early experiences lead to variations in children’s brain structures (Mustard, 2007) because the repeated use of a given cognitive skill contributes to the fine-tuning of underlying cortical systems (Zelazo & Lee, 2010). Thus, while neural structures undoubtedly subsume ToM performance, one may speculate that the development of ToM can also impact underlying brain structures. However, empirical evidence regarding prospective links between ToM and brain morphology among children is extremely thin. The present study aimed to examine the longitudinal associations between ToM performance and subsequent whole-brain grey matter (GM) volume in children.
ToM was assessed among 66 children (30 boys) when they were 6 and 7 years of age, using second-order false-belief stories (Perner & Wimmer, 1985; Sullivan et al., 1994). Structural magnetic resonance imaging was performed when children were 10 years of age. Preprocessing and whole-brain voxel-based morphometry analyses were performed using SPM12 and CAT12 (MATLAB). Multiple regressions were used to predict whole-brain regional GM volume from ToM performance (averaged across 6 and 7 years) controlling for child age, sex, total intracranial volume, and maternal education. Due to the exploratory nature of this study, an uncorrected threshold of p < .001 was used, with an extent threshold of 100 voxels. An explicit GM mask based on the mean normalized GM images of all participants was used to ensure that the analyses were restricted to GM.
Results showed that children who performed better on ToM tasks later presented larger GM volume in the right ventro-medial prefrontal cortex (vmPFC; MNI coordinates: x = 6, y = 62, z = -22; k = 184; T = 4.88) as well as smaller GM volume in the right precuneus (MNI coordinates: x = 9, y = -60, z = 63; k = 254; T = 4.26) and posterior cingulate cortex (PCC; MNI coordinates: x = 12, y = -2, z = 46; k = 144; T = 3.91). Both the vmPFC and precuneus have been found to be associated with socio-cognitive reasoning, such as perspective taking abilities and acquisition of social knowledge (Carrington & Bailey, 2009; Grossman, 2013; Saxe et al., 2009). As for the PCC, its functions are believed to be rather heterogeneous, including internally directed cognition, attention regulation and autobiographical memory (Leech & Sharp, 2013). The negative associations can perhaps be explained by the inverted U-shaped course of structural brain development; given that the parietal lobes reach maturity sooner, these regions might already have matured past their peak at the time MRI was performed (at age 10) and started decreasing in volume, thus indicating greater maturity.
Overall, the current results are the first to our knowledge to suggest the presence of associations between ToM and brain morphology among children. Early ToM development may impact the continuing development of neural structures supporting social cognition.

Authors

• Elie Yu Tong Guo, Université de Montréal (UdeM)
  Presenting Author

• Elizabel Leblanc, Université de Montréal
  Non-Presenting Author

• Fanny Dégeilh, Inria
  Non-Presenting Author

• Miriam Helen Beauchamp, Université de Montréal (UdeM)
  Non-Presenting Author

• Annie Bernier, University of Montreal
  Non-Presenting Author