Science & Technology

Bad last day ruined your holiday? Blame your brain

One part of our brains may overemphasise the importance of endings, which may explain why a disappointing final day of a holiday can taint our memories of an otherwise pleasant trip, according to UK researchers. The scientists used computer models to investigate the effects of choosing between two streams of coins, one of large coins and another of smaller coins. They found people were unhappy when the coins decreased in size over time, even when they were actually worth more, triggering them to pick the less valuable stream. They also scanned the brains of people undertaking the same task, and found an area of the brain called the amygdala kept track of the overall value of the coins, but in some people this was overpowered by another brain area, the anterior insula, which reacted if the coins reduced in size. This led them to undervalue an experience that had started well but ended poorly, the researchers say.


Happy Endings Trip Up the Brain’s Decision-Making
The neural representation of a pleasant ending can override the true value of an experience

The brain keeps track of the value of an experience as well as how it unfolds over time; overemphasizing the ending may trigger poor decision-making, according to new research published in JNeurosci.

A bout of bad weather at the end of a vacation can sour the impression of the entire trip. The tendency to focus on the ending may stem from how the brain encodes the value and temporal profile of an experience.

Vestergaard and Schultz created a computational model explaining how participants chose between two streams of coins varying in size where larger coins have a higher value. The model revealed a discrepancy between the true value of an experience — how much money was in the stream — and the value people placed on how it developed. People disliked when the coins decreased in size, even if the stream was worth more money overall, resulting in their making the wrong decision.

The findings from the model tracked with brain activity data from fMRI. During the task, the amygdala encoded the actual value of a choice, while the anterior insula encoded dislike towards a negative ending — in this case, if the coin stream decreased in size. This representation can overpower information from the amygdala, leading people to undervalue experiences that end poorly despite starting well. The best decision-makers had the strongest representation in the amygdala, indicating an ability to disregard a lesser ending and choose the better option.


From: Society for Neuroscience