Age differences in neural activity related to mentalizing during person perception

ABSTRACT

Mentalizing, or thinking about others’ mental states, shapes social interactions. Older adults (OA) have reduced mentalizing capacities reflected by lower medial prefrontal cortex (mPFC) activation. The current study assessed if OA’ lower mPFC activation reflects less spontaneous mentalizing during person perception. Younger adults (YA) and OA viewed ingroup White and outgroup Black and Asian faces and completed a mentalizing task during fMRI. Afterward, they completed a task in which they inferred mental states from faces. Using an mPFC region defined by the mentalizing task, OA had lower activity than YA during person perception. OA’ mPFC activity toward faces positively related to their mentalizing outside the scanner. The extent of OA’ lower mPFC activation during person perception may depend on their actual detection of mental states in faces. Further, YA’, but not OA’, mPFC activity distinguished between outgroups. OA’ lower mentalizing-related mPFC activity may reduce their ability to individuate outgroup members.

KEYWORDS:

• Mentalizing
• person perception
• medial prefrontal cortex
• race

Acknowledgments

This research was supported in part by NIMH grant T32MH103213 to C.H., and grant numbers KL2TR002530 and UL1TR002529 (A. Shekhar, PI) from the National Institutes of Health, National Center for Advancing Translational Sciences, Clinical and Translational Sciences Award to A.C.K. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. OA’ worse RME performance than YA has been shown to be driven by performance on negative items (Franklin & Zebrowitz, 2016). To explore this pattern in our data, we categorized RME items as positive (8 items), neutral (16 items), and negative (12 items) based on past work (Harkness, Sabbagh, Jacobson, Chowdrey, & Chen, 2005). We then entered RME accuracy into a 2 (Age: YA, OA)×3 (Valence: positive, neutral, negative) ANOVA. There was a main effect of Valence, F(2, 146)=7.60, p=.001, η_p²=.09, but no main effect of Age, F(1, 73)=.59, p=.59, η_p²<.01, and no interaction, F(2, 146)=1.27, p=.28, η_p²=.02. The main effect of Valence was driven by higher accuracy for positive (M=.79, SD=.17) versus negative (M=.71, SD=.15), F(1, 73)=11.11, p=.001, η_p²=.13, and neutral (M=.76, SD=.12) versus negative, F(1, 73)=11.96, p=.001, η_p²=.14, items. Accuracy did not differ between positive and neutral items, F(1, 73)=1.59, p=.21, η_p²=.02. Note that we present these data with caution because age differences for negative items have emerged with larger sample sizes and when treating valence as a continuous variable.

2. Because the RME task used White faces, exploratory analyses identified whether mPFC activity positively related to RME performance irrespective of race. OA’ mPFC activity toward White faces, r(33)=.34, p=.04, and toward Black faces, r(33)=.44, p=.008, positively related to RME performance. No significant correlation emerged for Asian faces, r(33)=.02, p=.92. YA’ RME mPFC activity toward White, r(38)=−.09, p=.59, Asian, r(38)=.05, p=.77, or Black, r(38)=−.15, p=.36, faces did not significantly relate to RME performance.

Additional information

Funding

This work was supported by the National Center for Advancing Translational Sciences [KL2TR002530,UL1TR002529];National Institute of Mental Health [T32MH103213].