Habitual Coffee Drinkers May Present Conditioned Responses from Coffee-Cue

Abstract

The present study was conducted to investigate whether the smell and sight of coffee (without tasting it) induced a conditioned response, and to compare the effect of the smell and sight of coffee in high- and low-consumption coffee drinkers. If classical conditioning caused the reduced reaction time effect, it was predicted that the degree of effect of caffeine-related stimuli would depend on the degree of experience of the pairing of conditioned stimulus (CS) and unconditioned stimulus (US). Sixty-six undergraduate students were randomly allocated to either a coffee or water presentation group and completed a simple reaction time task. Linear mixed modeling revealed that years of coffee consumption predicted reaction time when participants were presented coffee. The result coincided with the prediction that the greater the degree of experience of the pairing of CS and US, the greater the conditioned response would be. In conclusion, the present study showed that the smell and sight of coffee (without tasting it) induced a conditioned response and the direction was that of a caffeine-like effect. At least in behavioral effect, different types of caffeine CS uniformly induce a caffeine-like effect. Future studies should investigate the effect of the smell “or” sight of coffee to determine the relationship between CS type and direction of response.