The study – published in PLoS ONE – investigated how images of high- and low- calorie foods affected brain processing, and subsequent taste perception. The researchers, led by Dr Julie Hudry of the Nestlé Research Centre in Switzerland, reported that participants found a neutral tasting stimulus to be more pleasant when it was preceded by images of high-calorie foods, such as pizza or pastry.
Hudry and her colleagues used brain imaging technology to identify previously unknown brain mechanisms of visual-gustatory sensory interactions involved with food enjoyment. The authors said the study highlights the importance of visual food cues as an important determinant for food rewards.
“Taste is the primary driver for food acceptance or rejection, but our work suggests other sensory cues can provide the brain with essential information prior to food ingestion,” said Hudry.
“An individual’s evaluation of food before it is eaten is a crucial stage, not only for making nutritional choices but also affecting the experience of eating it ... Our work has yielded remarkable findings, which we will continue to build upon,” she explained.
Hudry told FoodNavigator that the study forms part of a wider programme of research on taste perception at the Nestlé Research Center.
“This is fundamental research to better understand the biological mechanisms of taste perception,” she said, explaining that current study has been published to help inform the work of researcher in the field.
“Data such as these are part of the wider research efforts by the scientific community as a whole to find new approaches for helping people to control their food intake, and ultimately body weight,” she said.
The authors noted that whilst it is well known that vision plays an important role in setting taste expectations for foods, and is a key driver of acceptance r rejection of foods – “so far, the impact of visual food cues varying in energy content on subsequent taste integration remains unexplored.”
Using electrical neuroimaging techniques, the team assessed if and how high- and low-calorie food cues differentially influenced brain processing, and perception of a later neutral ‘electric’ taste.
Participants in the study were shown images of foods with varying calorie content. They were then given an unfamiliar taste on their tongue using ‘electro-gustometry’.
This involved passing a gentle electric current through the tongue to create a unique and distinct metallic taste.
“When viewing high-calorie food images, participants reported the subsequent taste to be more pleasant than when low-calorie food images preceded the identical taste,” explained the researchers.
The Nestle teams study of the electrical activity in the brain using – combined with subjective data on which tastes the participants found the most enjoyable – led them to the conclude that looking at images of food influences subsequent taste perception.
“When eating, all our senses are stimulated simultaneously to create a unique perception of the food,” commented Hudry.