Anxiety: The pleasure principle

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  • Published: Aug 1, 2014
  • Author: David Bradley
  • Channels: MRI Spectroscopy
thumbnail image: Anxiety: The pleasure principle

Exciting choice

Positive and anxious feelings about making choices were associated with activity in different regions of the brain. Positive feelings correlated with activity in the lower parts of the striatum and the prefrontal cortex (green), while anxious feelings were correlated with the upper parts of these brain regions (red). Credit: Image courtesy of PNAS

Functional magnetic resonances imaging (fMRI) reveals activity in two different regions of the brain of people given a choice between two or more equally positive outcomes that give rise to both pleasure and anxiety simultaneously.

Amitai Shenhav, an associate research scholar at the Princeton Neuroscience Institute at Princeton University and colleagues had 42 volunteers rate the desirability of more than 300 different products using an auction-like procedure, among the items were desk lamps, water bottles, digital cameras, media players and the like. They then had the people look at images of the products in pairs of items of different or similar values and asked them to choose between them and to record their feelings before and while they were making their choices. The researchers monitored the volunteers' brain activity using fMRI while they were making their choices. The volunteers each received one of their choices on completion of the experiment.

Choices between two highly valued items (high-high), such as a digital camera and a camcorder, were associated with the most positive feelings and the greatest anxiety, compared with choices between items of low value (low-low), like a desk lamp and a water bottle, or between items of different values (low-high), the team reports in the journal Proceedings of the National Academy of Sciences. Intriguingly, the fMRI scans revealed activity in two different regions of the brain - the striatum and the prefrontal cortex. These two regions are thought to be associated with decision making. However, it was the lower parts of both regions that were seen to be the most active when the volunteers felt excited about being offered a choice, while activity in upper parts was strongly tied to feelings of anxiety.

Positive options

Shenhav and colleagues suggest that the experiment hints at two parallel brain circuits being involved in opposing emotional reactions when we are confronted with a dilemma. "Why isn't our positivity quelled by our anxiety, or our anxiety quelled by the fact that we're getting this really good thing at the end? Shenhav asks. "This suggests that it is because these circuits evolved for two different reasons," he adds. "One of them is about evaluating the thing we are going to get and the other is about guiding our actions and working out how difficult the choice will be."

The experiments were carried out by Shenhav whilst a graduate student at Harvard University under the supervision of Professor of Psychology and Neuroscience Randy Buckner. In a second fMRI study reported, the same patterns of emotional reactions and brain activity were seen to persist even when the volunteers were told beforehand how similarly the items had been valued. This did not abate their anxiety even though they were therefore fully aware of how little they would lose by making the "wrong" choice. Then, in a third experiment, Shenhav and Buckner tested whether giving the volunteers more than two choices increased their levels of anxiety. This was indeed the case. They found that giving the subjects six options led to even higher levels of anxiety than was seen with two options and this was particularly obvious when all six choices were high-value items. The positive feelings about being presented with a choice were similar irrespective of whether the volunteers were offered two or six options.

Choice anxiety

The team explains that this suggests that the anxiety arises not from the opportunity cost of the choice but simply from the conflict inherent in making the decision. The cost (the lost value of taking the second-best option) should be the same regardless of the number of choices, yet anxiety was not. In this final study, there was no time limit on making one's choice, whereas the first two studies required the volunteers to pick an item within 1.5 seconds of being shown the objects available. This suggests also that time pressure was not the main source of anxiety during the choices.

Perhaps even more intriguing was a twist at the end of each study. The participants were given the opportunity to reverse their earlier choices without being told in advance that such a switch would be offered. The team found that they could predict which items a particular volunteer would swap their original item for another based on their seeing greater activity in a part of the brain called the anterior cingulate cortex at the time the initial choice was made. This part of the brain was previously demonstrated to be associated with how conflicted a particular choice makes one feel. This extra result suggests that some choices may have continued to elicit conflict after the participant had made their decision, Shenhav adds. The researchers also found that people who reported more anxiety in their daily lives were more likely to change their minds.

The research might help explain our feelings of conflict given an ostensibly positive option even though the economic analysis would make the "right" choice obvious in terms of choosing a more valuable item. This seems paradoxical as one would not logically expect a person to feel anxious or worse about being given a choice of two valuable items. Nevertheless the fMRI results imply that two different mechanisms are in conflict in our brains when making such a choice and could explain why being given two great choices can still leave some people feeling negative about such an offer.

According to Shenhav, this research could shed light on the neural processes that can make more momentous choices so paralyzing for some people - for instance, deciding where to go to college or which job offer to take. But he admits that even more trivial decisions can be tough for him. "I probably experience more win-win choice anxiety than the average person," he said. "I'm even terrible at choosing where to eat dinner."

"The clearest conclusions of our study are with respect to the difference between circuits involved in feeling good about your options and feeling anxious about the choice," Shenhav told SpectroscopyNOW. "One of the important questions we want to address next is how this ties into behaviour. Our study looks at behaviour immediately after the choice, and ties the anxiety-related regions to indecision that persists at that point. In terms of those anxious feelings, we are interested in understanding how that choice anxiety and activity in related circuits affects longer-term feelings about one’s options, and how it influences choices to defer or avoid a choice altogether." He adds that, "In terms of the positive feelings people expressed, one thing we’re especially interested in pursuing is how these feelings might influence the decision to approach the options in the first place, to come to the display case or walk into the store after having first admired the things they have to offer from outside."

There is a second aspect to the results that Shenhav emphasised to SpectroscopyNOW. "We’ve been increasingly interested in how these costs are experienced (and potentially influence our behaviour) when that conflict isn’t between multiple items that are presented to us, but where we instead have a goal to engage with one option (like writing a scientific research paper) but have to continuously resolve conflict that arises from other, more tempting, options like email, Facebook, Twitter, and so on."

Related Links

Proc Natl Acad Sci 2014, online: "Neural correlates of dueling affective reactions to win–win choices"

Article by David Bradley

The views represented in this article are solely those of the author and do not necessarily represent those of John Wiley and Sons, Ltd.

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