New research published in PloS One demonstrates that our perception of taste can be influenced by visual images of food. Neuroimaging studies identified previously unknown brain mechanisms of visual-gustatory sensory interactions involved with food enjoyment.
According to the researchers, there is evidence that the mere viewing of food images activates taste-related brain areas and elicits expectations about the taste and hedonic aspects of the food. This is not surprising because visual cues constitute a primary sensory input indicating the pre-ingestive availability and palatability of food.
Notwithstanding, the sense of taste provides a major input for food perception. When presented alone, taste activates a cortical network including the insula/frontal operculum (FOP), orbitofrontal cortex (OFC), and anterior cingulate cortex (ACC). The human insula is involved in the processing of various sensory food properties including taste, oral texture, and oral temperature, but it is also believed to integrate multisensory information to establish an emotionally relevant context for sensory experience. The OFC has been particularly associated with hedonic aspects of sensory experience, the processing of food reward, and positive reinforcement irrespective of stimulus modality.
Subjects in the study were presented with 150 photographs depicting 100 food items and 50 non-food kitchen utensils. The food images were subdivided into high-calorie and low-calorie classes. An electrode measured taste detection thresholds.
The authors found that participants reported tastes to be more pleasant when preceded by images of high-calorie foods, such as pizza or pastry, as compared to low-calorie foods like watermelon or green beans.