A team of researchers led by Dr. Catharine Winstanley has identified differences in the brains of rats engaged in decision-making processes, revealing individual variability in cognitive effort and motivation and confirming that there is no one central decision-making region in the brain.
Many psychiatric disorders are associated with defects in decision-making, including bipolar disorder, psychopathy, drug and gambling addiction, and suicidal ideation. Understanding the mechanisms underlying the decision-making process is a promising step toward identifcation of new targets of intervention in these disorders.
These results were presented at the 2018 Canadian Neuroscience Meeting in Vancouver today.
Dr. Winstanley and her team engaged rats in a cognitive effort task in which the animals learn to earn treats by poking their noses into one of five response holes when a light inside one of the holes is illuminated.
Rats were given the option of pressing one of two levers. One lever corresponded with a reliably easy task, where the light flashed for one second, and offered a reward of one sugar pellet. The second lever corresponded with a task requiring more attention, where the light shone for only 0.2 seconds, but resulted in a reward of two sugar pellets.
The team found that some rats—”the slackers”—prefered the easier task, while others—the “workers”—prefered the more challenging task and its associated rewards. Interestingly, they found that individual choice did not correlate with the rat’s ability to complete the task, or the efficiency with which it could accomplish it.
