Salivary alpha-amylase levels and temporal discounting for primary reward under a simulated life-threatening condition.

OBJECTIVES: This study was aimed to examine the relationships between salivary alpha-amylase (sAA, a non-invasive biological marker of adrenergic activities) levels and hyperbolic discounting for primary reward under simulated life-threatening condition, which is of interest in psychoneuroendocrinology and neuroeconomics of visceral influences on behavior.

METHODS: We assessed degrees to which delayed primary reward (i.e., water) was discounted (hyperbolic discount rates) in 31 healthy male students. Participants' sAA were also assessed.

RESULTS: We observed a positive correlation between sAA and hyperbolic discounting for primary reward.

CONCLUSIONS: The result indicates that threat-induced visceral urge acutely prompts impulsivity in temporal discounting.