Haste Makes Waste: New Study Indicates the Brain is Less Accurate When Under Speed Stress
It’s often said that you can either have it fast or have it good, and according to recent research conducted at Vanderbilt University, it really does pay to go slow and think things out when taking a test or practicing a new skill.
The study, published in the journal Neuron, suggests that the brain switches into a different mode when it is forced to act quickly, essentially trading off accuracy for speed.
Previous research had already found evidence indicating that the brain makes this tradeoff, but researchers had always assumed it used the same basic method to make rapid or deliberate decisions. This study was the first to look at the decision-making process at the individual brain cell or neuron level.
“If we can understand how our brain changes when we are pushed to respond faster, we have gone a long way toward understanding the decision-making process in general,” commented Assistant Research Professor of Psychology, Richard P. Heitz.
In order to measure the activity of individual neurons, the researchers from Vanderbilt University trained monkeys to vary the speed of their decision making by teaching them to pick out a target from a variety of objects that were presented on a computer screen.
For one experiment, the monkeys were taught that they would only receive a reward when they responded with accuracy, while in the second experiment; they were taught that making a few mistakes along the way was okay, as long as they were making their decisions quickly.
While they were making their decisions, the researchers monitored signals from neurons in the prefrontal cortex, the area of the brain that deals with higher cognition.
“Our tests are like two different game shows. One – call it Fast Fury – is like Jeopardy. In order to answer a question you must be the first to hit the buzzer. Buzzing in and answering incorrectly is bad, but being slower than the other contestant means you will never earn a reward,” noted Heitz.
“That is much different than the second game show – call it High Stakes Showdown – where buzzing in at any time gives you the opportunity to answer a question, but being wrong results in a serious penalty.”
Heitz explains that the neural activity of the players in the fast paced game jumps up before the question has even been presented. On the other hand, the neural activity of the players in the game that values accuracy over speed drops lower as they consider the question.
So, even though the brain might be presented with the exact same information, if the decision is made under speed stress, the problem will be analyzed differently than it would be under accuracy stress. “The subjective experience of getting ready that we all experience appears to be reflected in the background activity of neurons in prefrontal cortex,” he said.
The researchers note in their report that this is contrary to the long-standing theory which says that the brain uses the same process for every type of decision. Instead, they conclude that the brain seems to deal with information in different ways, depending on the situation and what is expected of it.