Anxiety disengages a region of the brain called the prefrontal cortex (PFC), which is critical for flexible decision making, the findings showed.
By monitoring the activity of neurons in the PFC while anxious rats had to make decisions about how to get a reward, the scientists made two observations.
First, anxiety leads to bad decisions when there are conflicting distractors present. Second, bad decisions under anxiety involve numbing of PFC neurons.
The data indicates that anxiety has an exquisitely selective effect on neuronal activity that supports decision making, said lead author of the study Bita Moghaddam, professor at University of Pittsburgh in the US.
The study was published in The Journal of Neuroscience.
The researchers monitored the activity of a large number of neurons as rats made decisions about which choice was most optimal for receiving a reward.
They compared behavior and neuronal activity in two groups: one group that had a placebo injection and another that got a low dose of an anxiety-inducing drug.
As with many people who suffer from anxiety but go through day-to-day life and make decisions, the anxious rats completed the decision-making task and, actually, did not do too badly.
But they made far more mistakes when the correct choice involved ignoring distracting information.
“A brain locus of vulnerability for these anxiety-induced mistakes was a group of cells in the PFC that specifically coded for choice. Anxiety weakened the coding power of these neurons,” Moghaddam noted.
This better understanding of the brain mechanics behind anxiety and decision making could lead to better treatment of anxiety in people and, subsequently, better outcomes in the treatment of psychiatric disorders, she said. IANS