What happens in the brain when you take difficult decisions?

As the difficulty of making a decision increases, activity in a part of the brain that is crucial to making coherent thoughts also increases, a study says.

Researchers found a strong positive correlation between perceptual difficulty and activity in insular cortex which is generally divided into anterior insula, middle insula, and a posterior insula.

Perceptual decision-making is the process in which sensory information is gathered and used to influence our behaviour. For instance, if a person is driving and suddenly sees an object in front of the vehicle, he or she must decide what action to take, such as whether to slow down or bypass the object.

"This study found the activity of the anterior insulae can predict how well the sensory information is perceived or what the difficulty level of the perceptual task is," said Mukesh Dhamala, associate professor at Georgia State University in the US.

"This research is important because the anterior insulae, along with two nearby brain structures, make up the salience network, and when this network is impaired, it affects the ability to switch between tasks and make coherent thoughts,” Dhamala noted.

“Impairment in this network could possibly be linked to psychiatric illnesses, such as schizophrenia, dementia and autism, so it's essential to learn more about how this brain area should be functioning," he explained.

The findings were reported in the journal Neuroscience.

The study involved 33 people with normal or corrected-to-normal vision and normal neurological history. 

They completed four tasks, in which the researchers manipulated the visual and audiovisual stimuli to create varying degrees of task difficulty.

In all four experimental tasks, researchers found that anterior insulae activity consistently increased with task difficulty.