Many of the everyday decisions we make, such as “What am I going to buy for my brother’s birthday?” or “Where am I going to eat today?” are heavily based off the retrieval of relevant memories. In the past, the neural and cognitive mechanisms behind these decision-making processes were not studied. Despite the lack of careful examination, however, it is apparent that the hippocampus, the part of the brain devoted to memory storage region, and the ventromedial prefrontal cortex, responsible for decision-making and located in the frontal lobe, work hand-in-hand in decision-making.
In a recent study, a team of psychologists at the University of Basel asked 30 hungry young people to rate 48 snacks—such as crisps, chocolate bars, pretzels and wine gums—in order of preference. Then, things get interesting–the researchers presented the foods on computer screens in association with a particular location. For example, one of the participants could have been shown Oreos in relation to the movie theater. The subjects then went into a magnetic resonance image (MRI) scanner and chose repeatedly between two snacks in conjunction with a particular location; in essence, the subjects were shown a location and then given a choice between two foods in this study. The choices that the subjects made were astonishing.
The results of the study indicated that the participants were inclined to choose the snacks they best remembered. On a more interesting note, the study also highlighted a seemingly absurd trend: the participants often chose foods that they remembered best, even if they had rated them lower or considered them less attractive.
Image Source: Glow Wellness
Furthermore, the researchers established a control group to show that a relationship exists between memory and our food selection. The 30 members of this control group were directly shown the snacks on the screen. In this situation, the members selected snacks in accordance with their initial ratings.
In order to explain this trend, the research team utilized functional magnetic resonance imaging (fMRI) to study the neural mechanisms behind memory-based decisions. Through this process, the team were able to develop a mathematical model to represent the decision-making process and the influence of memory.
This model enabled the team to determine the strength of memory-based activation during memory storage in the hippocampus. These models, referred to as “spreading activation” models, seek to explain related ideas, primarily semantic and verbal ones. Through this modeling system, the team was able to verify something they had been suspecting: during memory-based decisions such as selecting food, there is a marked increase in the communication between the hippocampus and the ventromedial prefrontal cortex.
“Our study builds a bridge between two central research fields of psychology, that is, memory and decision-making research,” says Dr. Sebastian Gluth, lead author of the study. The combination of mathematical modeling and brain scans also provides an accurate understanding of how the areas of the brain are linked to the psychological sub-processes and how these areas interact with one another.
Feature Image Source: Food by Nik Stanbridge
