The influence of memory on food choice is mediated by increasing communication between the relevant brain areas, suggests a new study by psychologists at the University of Basel.
By offering different foods and using scans to track brain activity, researchers were able to show that the stronger our memory is of a certain food, the more likely we are to choose it. Even if it is the less attractive option.
Everyday decisions like “What bithday present should I give my son?” or “Where shall we go to eat?” are based on the retrieval of related information from memory.
It is known is that these brain processes involve the hippocampus, a classic memory region, and the ventromedial prefrontal cortex in the frontal lobe, a decision-making region. But until now, neural and cognitive mechanisms underlying this decision-making process had not been studied in depth.
The study involved psychologists asking 30 hungry young people to rate 48 snacks, such as chocolate bars, crisps, pretzels and wine gums, in order of preference. The snacks were presented on a computer screen in association with a particular location.
The subjects then went into a magnetic resonance image scanner and were asked to choose repeatedly between two snacks, for which only the location was shown. The subjects were thus forced to recall the snack associated with the location.
Results showed that the students tended to prefer the snacks that they were able to recall better.
And they chose the snacks they could recall better even if they had rated them lower in the initial task and therefore considered them less attractive.
Only highly unappealing snacks were rejected even if they were remembered. The control group of 30 subjects was shown the snacks directly on the screen and its choices corresponded with the initial ratings.
Why Brain Scans
Functional magnetic resonance imaging (fMRI) was used to investigate the neural mechanisms of memory-based decisions, and to develop a mathematical model to represent the decision-making process and the influence of memory.
This model allowed the team to determine the strength of memory-based activation during storage in the hippocampus. An analysis of the activation during the decision-making process showed an increase in communication between the hippocampus and the ventromedial prefrontal cortex.
Lead author Dr. Sebastian Gluth said:
“Our study builds a bridge between two central research fields of psychology, that is, memory and decision-making research.”
The fusion of mathematical modeling and brain scans also gives a more accurate understanding of how the areas of the brain are linked to the psychological sub-processes and how these areas interact with one another.
Sebastian Gluth, Tobias Sommer, Jörg Rieskamp, Christian Büchel
Effective Connectivity between Hippocampus and Ventromedial Prefrontal Cortex Controls Preferential Choices from Memory
Neuron, Vol. 86, No. 4. (21 May 2015), pp. 1078-1090, doi:10.1016/j.neuron.2015.04.023
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