New University of California (Berkeley) research suggests that our brain activity can be influenced in order to help us make healthier choices for ourselves. Researchers have recorded moment-to-moment deliberations by macaque monkeys over which option will most likely lead to the most fruit juice being offered, capturing the dynamics of decision-making down to millisecond changes in neurons in the brain’s orbitofrontal cortex.
The complete findings of the study have been published within Nature Neuroscience journal and shed a completely new light on the internal decision-making process, especially in regard to habitual behaviors. This helps to target the brain circuitry for implants to treat neuropsychiatric disorders such as anxiety, depression and even addiction.
Senior author of the study Jonathan Wallis says that if we can measure a decision in real time, we hold the potential to be able to manipulate the outcome as well. For example, there could be a device created that detects when an addict is about to choose a drug and instead change the brain activity towards a much healthier choice and one with less regret and negative consequences.
The orbitofrontal cortex is located behind the eyes and plays a key role in decision making. When this area of the brain becomes damaged, it can lead to increased impulsivity and a tendency to reach towards poor choices instead of good ones that will benefit us in the long run. Previous studies have been able to link the orbitofrontal cortex to final decision making, but this is the first time the actual neural changes have been tracked as deliberations are considered between a number of options. Wallis says for the first time, we are able to watch as decisions unfold in real time and make predictions as to what the final choice will be.
Wallis and his fellow researchers implanted electrodes into the brains of monkeys, which they measured the signals of. They were then able to track the neural activity as they weighed both the pros and cons of images that delivered different amounts of juice.
A computational algorithm tracked the monkeys’ orbitofrontal activity as they viewed image after image, trying to decide which picture would offer them the biggest and best reward. The changing brain patterns enabled researchers to predict which image each monkey would decide on.
During the experiment, monkeys were shown a series of four different images of abstract shapes, each with a different amount of juice offered as a reward. They used a pattern-recognition algorithm known as linear discriminant analysis to identify, with the given pattern of neural activity, which picture that monkey was looking at.
Next up, monkeys were shown two of the images from before and researchers watched as the neural patterns switched back and forth to the point where the researchers were able to predict which image the monkey would choose based on the amount of time they stared at each photo. Wallis says the team was able to effectively see the decision as it was about to unfold and make predictions about the choice the animal was about to make.
The more the monkey needed to consider their options, especially in cases where there was not a big difference between the amounts of juice being given, the more neural patterns would switch back and forth. Wallis says now that we are able to see when the brain is considering a particular choice, we may potentially be able to use that signal in order to electrically stimulate the neural circuits involved in the decision and change the final choice as it is about to be made.