Age-related striatal BOLD changes without changes in behavioral loss aversion

Abstract

Loss aversion (LA), the idea that negative valuations have a higher psychological impact than positive ones, is considered an important variable in consumer research. The literature on aging and behavior suggests older individuals may show more LA, although it is not clear if this is an effect of aging in general (as in the continuum from age 20 and 50 years), or of the state of older age (e.g., past age 65 years). We also have not yet identified the potential biological effects of aging on the neural processing of LA. In the current study we used a cohort of subjects with a 30 year range of ages, and performed whole brain functional MRI (fMRI) to examine the ventral striatum/nucleus accumbens (VS/NAc) response during a passive viewing of affective faces with model-based fMRI analysis incorporating behavioral data from a validated approach/avoidance task with the same stimuli. Our a priori focus on the VS/NAc was based on (1) the VS/NAc being a central region for reward/aversion processing; (2) its activation to both positive and negative stimuli; (3) its reported involvement with tracking LA. LA from approach/avoidance to affective faces showed excellent fidelity to published measures of LA. Imaging results were then compared to the behavioral measure of LA using the same affective faces. Although there was no relationship between age and LA, we observed increasing neural differential sensitivity (NDS) of the VS/NAc to avoidance responses (negative valuations) relative to approach responses (positive valuations) with increasing age. These findings suggest that a central region for reward/aversion processing changes with age, and may require more activation to produce the same LA behavior as in younger individuals, consistent with the idea of neural efficiency observed with high IQ individuals showing less brain activation to complete the same task.

A Quantitative Relationship between Signal Detection in Attention and Approach/Avoidance Behavior

“…Second, we calculated the Shannon entropy (i.e., information; see Shannon and Weaver, 1949 ) of the distribution of keypress counts to approach ( H + ) or avoid ( H − ) the face stimuli within each category. Keypress measures of value such as those reported here have also been studied in the context of neuroimaging data, and have been specifically linked to activation of reward circuitry (Aharon et al, 2001 ; Strauss et al, 2005 ; Perlis et al, 2008 ; Gasic et al, 2009 ; Viswanathan et al, 2015 ) that appears affected by genotype (Perlis et al, 2008 ; Gasic et al, 2009 ). In addition, pattern variables such as Shannon entropy have been shown to be important metrics for quantifying neural processing (Viola et al, 1996 ; Rieke, 1997 ; Tiesinga et al, 2002 ; Reeke and Coop, 2004 ), and define the “information” that is processed in cognitive neuroscience (Breiter et al, 2006 ; Kim et al, 2010 ).…”

“…The approach/avoidance task (Kim et al, 2010 ) gauged to what extent subjects would actively keypress to increase or decrease the amount of time they were exposed to face stimuli belonging to four categories: non-model male, non-model female, model male, and model female faces (Aharon et al, 2001 ). This validated task (Aharon et al, 2001 ; Elman et al, 2005 ; Strauss et al, 2005 ; Levy et al, 2008 ; Perlis et al, 2008 ; Gasic et al, 2009 ; Yamamoto et al, 2009 ; Kim et al, 2010 ; Viswanathan et al, 2015 ) quantified the effort subjects were willing to expend to approach or avoid each face stimulus. We then computed metrics that quantified the magnitude and predictability of the participants' keypress behavior.…”

Gender and Age Related Effects While Watching TV Advertisements: An EEG Study

“…In a recent fMRI study, no relationship has been observed between age and LA, but an increasing neural differential sensitivity of the Ventral Striatum (VS)/Nucleus Accumbens (NAc) to avoidance responses (negative valuations) relative to approach responses (positive valuations) has been evidenced with aging. These findings suggest that a central region for reward/aversion processing (VS/NAc) changes with age [ 27 ]. The same cerebral regions involved in the reward/aversion system, such as the NAc, caudate, and putamen, are also engaged in reaction to humoristic stimuli [ 28 ].…”

Reward learning impairment and avoidance and rumination responses at the end of Engage therapy of late‐life depression

“…Aging‐related dysfunction of the reward system may be a contributor. The brain's reward system, comprised by the amygdala, ventral tegmental area, nucleus accumbens, ventral striatum, medial prefrontal cortex, and orbitofrontal cortex, is particularly susceptible to the effects of aging evidenced by microstructural changes in white matter and in functional connectivity . These neural abnormalities are strongly associated with disrupted reward‐related behaviors during aging .…”