The foods we choose to eat greatly influence our overall health. These decisions depend upon the perception of flavor; a multisensory process requiring the senses of smell and taste. Eating a food drives associations between an odor and a taste’s quality (i.e. chemical identity) and hedonic value (i.e. pleasantness/unpleasantness), resulting in behavioral preferences for odors paired with pleasant tastes and avoidance of odors paired with unpleasant tastes.
We use an array of behavioral techniques to investigate how experience with odor-taste mixtures informs consummatory choice.
Two-bottle brief-access task
In the two-bottle brief-access task, the rat has a limited amount of time to drink from 2 simultaneously presented bottles containing different stimuli. The number of times each bottle is sampled (i.e., licks) and the number of trials in which the rat engages are measures of consummatory behavior. The difference between the number of times the 2 bottles are sampled is a measure of the rat's preference.
Lateral tongue protrusion
Like most mammals (including humans), rats produce stereotypical orofacial behaviors when they eat something palatable (e.g., sucrose) or unpalatable (e.g. citric acid). Rats produce lateral tongue protrusions (LTPs; top left) when sampling something pleasant and respond to unpleasant stimuli with a gape (top right). We can infer how much a rat likes or dislikes a stimulus by quantifying the number of times each of these behaviors occurs.