Why the brain can overvalue a happy ending

The human brain is, well, only human. People generally tend to overlook future consequences, misattribute the motivations of others' behavior, and underestimate the time and effort of personal tasks.

According to a recent study, the brain also overvalues the ending of experience rather than accurately summarizing the total value of the experience as it goes along. This finding was published Monday in the Journal of Neuroscience.

In turn, this cognitive bias can screw up day-to-day decision-making. It also helps explain why a bout of bad weather colors the memory of an otherwise blissful vacation, or why an unpalatable dessert can tarnish the experience of a glorious meal.

"Practically speaking, we make decisions according to what we have more recently experienced, compared to earlier events," study co-author Wolfram Schultz, a neuroscientist at the University of Cambridge, tells Inverse.

"Behavior becomes a bit myopic, driven more by the recent experience, which is weighed more heavily, than by earlier experiences, which are weighed less."

Luckily, we don't have to be passive victims of our neural machinery. By understanding this cognitive bias and harnessing rational decision-making, we can mitigate the effects of this timing bias.

"The core of the problem is a difference between what we enjoy while it lasts and what we want again after the final impression," Schultz says. "Focusing on the happy end maximizes our final impression, not our overall enjoyment."

Endings, beginnings— To better understand how the brain encodes the value of experiences across different timescales, Schultz and his team designed a computer model and had 28 healthy male volunteers estimate the value of two virtual streams of coins and choose the more valuable stream. The coins varied in size, with larger coins having a larger value.

"Focusing on the happy end maximizes our final impression, not our overall enjoyment."

Ultimately, the participants disliked when the coins decreased in size, even if the stream was worth more money overall, leading them to choose the less valuable stream — a poor choice.

"Memory is better for more recent events, and the brain takes these more into account as compared to earlier events," Schultz explains. "Basically, what had occurred earlier is less important for our future compared to what has just very recently occurred."

Throughout the experiment, scientists tracked the group's brain activity using fMRI technology. This revealed that during the task the brain's amygdala encoded the actual value of a choice, while the anterior insula encoded dislike towards a negative ending (if the coin stream decreased in size).

Overall, the best decision-makers had the strongest representation in the amygdala, indicating an ability to disregard a lesser ending and choose the better option.

"Good decision-makers show a strong representation of the overall value in the amygdala, whereas suboptimal decision-makers encode the disappointing end too strongly," Schultz says.

Optimizing decision-making — Even though this neural dynamic is at play without much conscious thought, there are ways to actively apply this information to make better decisions, the researchers say.

"Our daily behavior becomes rather narrowly focused on the immediate past if we just follow these impulses," Schultz says. "We can, of course, think about what we are doing using our prefrontal cortex and then overrule these recency impulses as much as we find useful."

Reflecting on pros and cons is one strategy to support ourselves into wiser decisions, Schultz adds.

"This is essentially a way to take an analytic approach to at least complement if not overrule our more intuitive impression," he explains.

Next time you find yourself ruminating on the conclusion of a program or past scenario rather than thinking it through step by step, remember this may be your brain's tricky cognitive biases shading reality. Rather than go with your gut, pause, reflect, and then move forward. Your future will thank you.

Abstract: Our ability to evaluate an experience retrospectively is important because it allows us to summarize its total value, and this summary value can then later be used as a guide in deciding whether the experience merits repeating, or whether instead it should rather be avoided. However, when an experience unfolds over time, humans tend to assign disproportionate weight to the later part of the experience, and this can lead to poor choice in repeating, or avoiding experience. Using model-based computational analyses of fMRI recordings in 27 male volunteers, we show that the human brain encodes the summary value of an extended sequence of outcomes in two distinct reward representations. We find that the overall experienced value is encoded accurately in the amygdala, but its merit is excessively marked down by disincentive anterior insula activity if the sequence of experienced outcomes declines temporarily. Moreover, the statistical strength of this neural code can separate efficient decision-makers from suboptimal decision-makers. Optimal decision-makers encode overall value more strongly, and suboptimal decision-makers encode the disincentive markdown more strongly. The separate neural implementation of the two distinct reward representations confirms that suboptimal choice for temporally extended outcomes can be the result of robust neural representation of a displeasing aspect of the experience such as temporary decline.