When making decisions, people not only compare their options, but also evaluate how they feel about those options. These two processes should be reflected in distinct neural activity, with an evaluation process reflected in activity shortly after options are presented, in addition to a choice process leading to the response. This was tested by looking at neural activity measured with EEG synchronized to when options were displayed as well as when choices were made, and how activity at each time point related to how whose options people liked and the difficulty of choice. was. Credit: Human behavior (2024). DOI: 10.1038/s41562-024-01971-z
Previous neuroscience research has identified patterns of neural activity typically observed when humans are engaged in value-based decision-making. It is the process by which humans choose between options that might be linked to different costs and rewards, carefully weighing their options based on their own preferences, goals, and expectations.
Researchers at Brown University and the University of Birmingham recently conducted a study aimed at further elucidating the neural signatures of value-based decision making discovered in previous papers, which closely resemble those underlying the accumulation of evidence supposed to precede choice.
Their findings, published in Human behaviorsuggest that in this context, these signatures are not actually linked to the accumulation of evidence, but rather reflect choice-independent processes.
“Our study was inspired by the intuition that when we make decisions, we often not only compare our options, but we also feel certain things about them,” said Dr. Romy Froemer, first author of the paper , at Medical Xpress.
“For example, when we have interesting options to choose from, like when I’m choosing between tasty breakfast options at this amazing vegan place I discovered in Ghent earlier this summer, we don’t just think about which is the best.
“We also think about how great all these options are. That seems very different from when all the options are not so great, like when I think about the packaged sandwiches they sell for lunch in our college cafes.”
In his previous studies, one of the authors of this recent paper, Amitai Shenhav, showed that the extent to which people like the options available to them when making a values-based decision was correlated with activity in specific areas of the brain, while difficulty humans chose an option correlated with activity in other regions of the brain.
Although his findings are informative, they do not clarify at what point in decision making these two different processes (evaluation and comparison of choices) occur.
“To study this, we needed a different technique that could tell us what’s happening in the brain at every moment, on the scale of milliseconds,” Froemer said. “To see if we could identify the neural activity associated with what people think about their options, we used EEG, a method that has this exact property of being able to tell us, millisecond by millisecond, what the neuronal activity.”
People who participated in the team’s study were asked to wear caps with electrodes mounted on them while they made various values-based decisions. The decisions they had to make varied both in terms of the quality of the options available and the difficulty in choosing the best one.
“We expected that these two properties of the data would correlate differently with neuronal activity in the EEG,” Froemer explained. “We predicted that we would see neural activity associated with how people perceive their options early on, shortly after seeing the options, and distinct neural activity associated with the difficulty of the choice leading to the response, and especially not vice versa.
“We tested these predictions by examining neural activity during choice in two ways, one synchronized with the time the options appeared and the other synchronized with the time participants made their decisions .”
Distinct neural activity was associated with how much people liked the options (evaluation) and the difficulty of the choice (choice). As expected, the former was reflected in neural activity shortly after the options were displayed, while the latter was reflected in the activity leading up to the decision. Surprisingly, the choice-related activity (later) did not look at all like the expected pattern based on the earlier results (top), indicating that it may not reflect the choice-related activity either . Credit: Human behavior (2024). DOI: 10.1038/s41562-024-01971-z
Subsequently, the researchers examined neural activity at two different times: when possible choice options appeared and when participants made the decision. Their goal was to determine whether neural activity at these two stages varied depending on how participants judged the options available and how difficult it was for them to make a decision.
“First, as expected, we found that neural activity followed this evaluation process (indicating how much people like their options as they made their choice) regardless of the difficulty of that choice and well earlier than expected by activity associated with decision-making,” Froemer said. “This means that when we make decisions, we do not only make decisions and, therefore, that neural activity during decision-making does not necessarily reflect decision-making per se, if at all. Our brain and mind can do a lot of things at the same time. »
The second discovery of this recent study surprised the researchers. Specifically, the team found that the neural activity related to the difficulty of deciding between options did not resemble a signal they expected to observe when making a decision.
“Previous work combining mathematical models of decision-making with EEG had described what neural activity associated with decision-making should look like and our data looked nothing like that,” Froemer explained.
“In fact, we found that there may be a completely different explanation for why previous studies had found data that resembled neural activity in the decision-making brain. This means we need to be very careful about conclude that the neural activity that correlates with the difficulty of a choice reflects that choice process itself.
The recent study by Froemer and colleagues gathered interesting new insights into the neural activity patterns underlying value-based decision-making and its various dimensions. Although their results suggest that choice-related neural signals may emerge artificially from choice-independent processes, this interesting event remains poorly understood.
“We still don’t know for sure what the activity we found associated with choice difficulty means,” Froemer said. “We think these may be the processes that evaluate and guide the ongoing decision-making process, but more research is needed to understand this.”
The results of this recent study may soon inspire additional research investigating the neural signatures of value-based decision-making under different conditions. In their next papers, Froemer and his colleagues plan to continue studying the complex processes that the human brain relies on to guide decision-making.
“For example, we need to determine how to explore each of our options, how long we should explore them before making a decision, what type of decision we want to make, such as choosing the best or avoiding the worst, whether we should decide or go do something else, and how each of these processes is reflected in neuronal activity,” Froemer added.
“If we understand these processes better, we may be able to gain insight and help people who have difficulty making decisions, such as people suffering from depression, obsessive-compulsive disorder or addiction.”
More information:
Romy Frömer et al, Common neural choice signals can emerge artificially amidst several distinct value signals, Human behavior (2024). DOI: 10.1038/s41562-024-01971-z
© 2024 Science X Network
Quote: Neural signatures commonly observed when humans make choices may also reflect choice-independent processes (2024, October 5) retrieved October 5, 2024 from
This document is subject to copyright. Except for fair use for private study or research purposes, no part may be reproduced without written permission. The content is provided for informational purposes only.
