An illusion you can sink your teeth into: haptic cues modulate the perceived freshness and crispness of pretzels.

Eating is a multisensory experience involving more than simply the oral sensation of the taste and smell of foods. It has been shown that the way foods look, sound, and feel like in the mouth all affect food perception. The influence of haptic information available when handling food is relatively unknown. In this study, blindfolded participants bit-into fresh or stale pretzels while rating their freshness staleness and crispness-softness. Information provided to the hand was either congruent (whole pretzel fresh or stale) or incongruent (half pretzel fresh, half stale) with what was presented to the mouth. The results demonstrate that the perception of both freshness and crispness was systematically altered when incongruent information was provided: bit-into fresh pretzel tips were perceived as staler and softer when a stale pretzel tip was held in the hand and vice versa. Haptic information available when handling food thus plays a significant role in modulating food perception.