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Journal Article 2010; 31(6): 771-774 PubMed PMID: 21196913 Citation  Keywords:  Adult, Age Factors, Aged, Female, Humans, Male, Middle Aged, Personality, Personality Inventory, Saliva:enzymology, Salivary alpha-Amylases:metabolism, Surveys and Questionnaires,.   

OBJECTIVES: Salivary alpha-amylase (sAA) has been utilized as a non-invasive measure of sympathoadrenal medullary (SAM) activation. Little is known regarding the relationship between personality inventories and baseline sAA. This study was designed to examine the relationships between the scores of big five inventory (BFI) factors, age, and sAA in adults (aged twenty to seventy years old).

METHODS: We assessed 97 participants' BFI scores and sAA. The correlations between the BFI factor scores and sAA were examined.

RESULTS: We observed (1) a positive correlation between Neuroticism and sAA, and a negative correlation between Agreeableness and sAA and (2) a positive correlation between age and sAA. These correlations between BFI scores and sAA remained significant after controlling for age. After controlling for age, all BFI factors except Conscientiousness were related to sAA.

CONCLUSIONS: Subjects with high Neuroticism and low Extraversion, Agreeableness and Openness may have high sAA. sAA has been demonstrated to be useful for examining the relationship between adrenergic activity and personality, in a non-invasive manner....

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Journal Article 2009; 30(5): 643-646 PubMed PMID: 20035253 Citation  Keywords:  Adolescent, Choice Behavior:physiology, Decision Making:physiology, Emotions:physiology, Female, Games, Experimental, Humans, Neuropsychological Tests, Saliva:enzymology, Salivary alpha-Amylases:metabolism, Young Adult,.   

OBJECTIVES: This study aimed to examine the role of emotions in rejection of unfair offers in an ultimatum game, which is of interest in neuroeconomics of fairness.

METHODS: Thirty-seven participants played a one-shot ultimatum game as responders and decided whether to accept or reject the unfair offers by the proposers. Salivary alpha-amylase (sAA) was assessed before and after the ultimatum game.

RESULTS: Forty-four percent of the participants rejected the unfair offers. While sAA levels of the participants who rejected the unfair offers increased between pre- and post-experiment, sAA levels of the participants who accepted the unfair offers remain unchanged.

CONCLUSIONS: Emotional stress response was observed when participants rejected the unfair offers. Our results indicated that rejection of the unfair offers is a reflection of emotional arousal associated with adrenergic activations....

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Journal Article 2008; 29(4): 451-453 PubMed PMID: 18766143 Citation  Keywords:  Humans, Impulsive Behavior, Male, Neuroendocrinology, Reward, Saliva:enzymology, Statistics as Topic, Surveys and Questionnaires, alpha-Amylases:metabolism,.   

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....

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Journal Article 2007; 28(5): 662-665 PubMed PMID: 17984929 Citation  Keywords:  Adolescent, Adult, Altruism, Amylases:metabolism, Decision Making:physiology, Games, Experimental, Humans, Male, Reference Values, Reward, Saliva:metabolism, Self Concept, Social Perception,.   

OBJECTIVE: Little is known regarding the relationship between social evaluation-induced neuroendocrine responses and generosity in game-theoretic situations. Previous studies demonstrated that reputation formation plays a pivotal role in prosocial behavior. This study aimed to examine the relationships between a social evaluation-induced salivary alpha-amylase (sAA) response and generosity in the dictator game. The relationship is potentially important in neuroeconomics of altruism and game theory.

METHODS: We assessed sAA and allocated money in the dictator game in male students with and without social evaluation. RESULTS Social evaluation-responders allocated significantly more money than controls; while there was no significant correlation between social evaluation-induced sAA elevation and the allocated money.

CONCLUSIONS: Social evaluation significantly increases generosity in the dictator game, and individual differences in trait characteristics such as altruism and reward sensitivity may be important determinants of generosity in the dictator game task....

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