Food choices influenced by memory

You have a choice between two foods: a chocolate bar or a piece of cake. What influences your decision? The desire to be healthy? The need for a sugar boost? According to a new study, your choice may be influenced by your memory of a particular food. A stronger memory association with an apple, for example, may encourage you to opt for the apple, even if the cake is the more attractive choice.

The study also reveals that the influence of memories in food choice is driven by an increase in communication between two brain regions - the hippocampus and the ventromedial prefrontal cortex.

Study leader Dr. Sebastian Gluth and colleagues, from the University of Basel in Switzerland, publish their findings in the journal Neuron.

According to the researchers, many everyday decisions we make - such as "Where shall we go for dinner?" - are guided by information retrieved from our memories. However, the neurological processes underlying such decisions were unclear. Dr. Gluth and colleagues set out to gain a better understanding of these processes.

The team enrolled 60 young participants to their study and showed them 48 snacks - including chocolate bars, pretzels and chips - on a computer screen. Each snack was allocated to a specific location on the screen, and the participants were asked to rate each snack in order of preference.

Next, the participants underwent functional magnetic resonance imaging (fMRI), during which they were repeatedly asked to choose between two snacks. However, 30 participants were only shown the location of the snack, meaning they had to recall the snack linked to each location. The other 30 participants were shown the snacks directly on the screen. 

Participants were more likely to choose snacks they could remember

From their experiment, the researchers found that participants opted for the snacks they were better able to recall the location of. What is more, subjects chose they snacks they could recall better even if they had rated them lower in preference previously.

The food choices of the 30 participants who were shown the snacks directly on the screen during fMRI correlated with their previous preference ratings.

From the fMRI scans, the team was able to assess the brain activity of participants during their memory-based food choices. This enabled them to create a mathematical model showing how memories influence the decision-making process.

From this, they identified an increase in communication between the hippocampus - the brain region involved in memory - and the ventromedial prefrontal cortex - the decision-making brain region - as participants made their food choices.