A stronger relationship between reward responsivity and trustworthiness evaluations emerges in healthy aging

ABSTRACT

Older adults (OA) evaluate faces to be more trustworthy than do younger adults (YA), yet the processes supporting these more positive evaluations are unclear. This study identified neural mechanisms spontaneously engaged during face perception that differentially relate to OA’ and YA’ later trustworthiness evaluations. We examined two mechanisms: salience (reflected by amygdala activation) and reward (reflected by caudate activation) – both of which are implicated in evaluating trustworthiness. We emphasized the salience and reward value of specific faces by having OA and YA evaluate ingroup male White and outgroup Black and Asian faces. Participants perceived faces during fMRI and made trustworthiness evaluations after the scan. OA rated White and Black faces as more trustworthy than YA. OA had a stronger positive relationship between caudate activity and trustworthiness than YA when perceiving ingroup, but not outgroup, faces. Ingroup cues might intensify how trustworthiness is rewarding to OA, potentially reinforcing their overall positivity.

KEYWORDS:

• Trustworthiness
• reward
• caudate
• race
• aging

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. The authors declare no conflicts of interest.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Notes

1. Because caudate responds to both aversive and rewarding facial characteristics (Liang et al., 2010), we also tested for quadratic effects of trustworthiness evaluations and caudate activity in YA and OA. The three-way interaction between Age Group, Target Race, and Hemisphere was not significant, F(2, 142)=.67, p=.52, η_p²=.009. The two-way interaction between Age Group and Target Race was not significant, F(2, 142)=.22, p=.80, η_p²=.003.

Additional information

Funding

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