Brain damage When does your brain think something is worth the wait? People with brain injuries differ in their ability to figure out when waiting pays. Elizabeth Rayne Dec 30, 2024 8:15 am | 2 Credit: Yellow Dog Productions via Getty Credit: Yellow Dog Productions via Getty Story textSizeSmallStandardLargeWidth *StandardWideLinksStandardOrange* Subscribers only Learn moreWhether its braving the long line at a trendy new restaurant or hanging on just a few minutes longer to see if theres a post-credits scene after a movie, the decision to persevere or ditch it depends on specific regions of our brains.Waiting is not always about self-control. Deciding to wait (or not to wait) also involves gauging the value of the potential reward. In an experiment that investigated wait times among people with lesions in the frontal cortex of the brain, University of Pennsylvania psychologist Joe Kable and his research team found that subjects with damage to certain regions of the prefrontal cortex were less likely to wait things out.[Our] findings suggest that regions of the frontal cortex make computationally distinct contributions to adaptive persistence, he and his team said in a study recently published in the Journal of Neuroscience.Wait for itKable looked for subjects with damage to three parts of the prefrontal cortex: the ventromedial prefrontal cortex, dorsomedial prefrontal cortex and anterior insula. Their behavior was compared to both healthy controls and controls with lesions in the other parts of the frontal cortex.The ventromedial prefrontal cortex is involved with action control, memory, and making decisions. The dorsomedial prefrontal cortex is even more important when it comes to decision-making; it also has an integral role in regulating cognition, emotion, and action. The anterior insula regulates how subjective feelings are processed. The performance of subjects with lesions in these areas was compared not just to healthy controls, but controls with lesions in other regions of the frontal cortex.Participants sitting in front of a computer screen were told that a coin would appear on the screen. That coin was supposed to increase in value over time and change color when its value matured. It could then be sold for a 10 cent reward by pressing the space bar. Even if the coin hadnt matured yet, the space bar could still be pressed to stop the waiting period and make a new coin appear, though they missed out on the 10 cents.What nobody participating in this experiment knew was that the coins maturation followed one of two patterns. In the high-persistence pattern, the coin could mature any time during a period of 20 seconds, so waiting was the best strategy. Conversely, in the limited-persistence alternative, it was optimal to stop waiting a little after two seconds if the coin didnt mature by then, because if it didnt, it would go without maturing for the full 40 seconds The purpose of this test was to make as much money as possible in 12 minutes.When a subject decided to sell a coin, the screen would flash the word SOLD in red for one second while a countdown bar on the bottom kept track of how much time was left.Worth it?The research team found that the groups with specific lesions showed deficits in their ability to calibrate wait duration, and their behavior differed significantly from that of healthy controls, as they said in the same study.Those with lesions to the ventromedial prefrontal cortex showed that they were initially less willing to wait for a reward, regardless of whether they were being subjected to the high-persistence or low-persistence condition. While they did wait longer during the high persistence tests, their wait times were still significantly shorter than those of frontal controls and healthy controls. Kable and his team think this is because of subjectivity; they did not think waiting longer was worth it for them, even with a reward on the line.Those with lesions in the other two areas had wait times close to the healthy controls, but this was not because those parts of the brain dont factor into waiting behavior. Subjects with damage to these regions were not as sensitive to the time constraints required for a reward. Because of this, their willingness to wait did not increase or decrease much over the length of the experiment. They also had difficulty learning from the trials in which they quit: If they quit before a coin matured, they were likely to do it again.Waiting times for the control group with other frontal damage were similar to those of healthy controls.Waiting for moreWhile this study showed that lesions in certain parts of the brain affect the overall willingness to wait (vmPFC lesions) and ability to learn from quitting in the past (dmPFC and AI lesions), it could have further implications. There are many mental conditions that involve a tendency to either wait much too long or not enough. How the brain processes waiting for rewards in people with these conditions is something that Kable and his team intend to study in the near future. It will be worth the wait.Journal of Neuroscience, 2024. DOI: 10.1523/JNEUROSCI.0068-24.2024Elizabeth Rayne Elizabeth Rayne is a creature who writes. Her work has appeared on SYFY WIRE, Space.com, Live Science, Grunge, Den of Geek, and Forbidden Futures. She lurks right outside New York City with her parrot, Lestat. When not writing, she is either shapeshifting, drawing, or cosplaying as a character nobody has ever heard of. Follow her on Threads and Instagram @quothravenrayne. 2 Comments