Coordinated ‘noise’ between brain neurons helps animals predict outcomes to make optimal decisions
New research has shone light on the role of the brain’s neurons in decision-making processes.
The research, published in PLOS Computational Biology, investigated how the brain encodes whether the outcome of a choice can be predicted on the basis of previous experience.
It found that coordinated responses by up to three neurons could contribute to the ability of animals to make optimal decisions.
Neuronal responses can differ substantially during repetitions of the same tasks, known as ‘trail-by-trial noise’ and the study explored whether this noise in the responses of neurons helps or hinders the capacity of the brain to assess optimal decisions.
Dr Emili Balaguer-Ballester, Associate Professor in Computational Neuroscience at Bournemouth University, led the research.
He said: “Electrical responses of neurons can differ substantially when we measure them over multiple repetitions of the exact same task.
“Consider a lab rat that pokes its nose in the same socket to retrieve juice every time a task is repeated. In his situation, responses of the same neurons in brain areas in charge of the decision-making process, can look very different every time.
“Is this ‘neuronal noise’ a benefit or a hazard for the brain to evaluate the result of a decision?”
The study focused on neurons in an area of the brain known as the orbitofrontal cortex (OFC), which has been found in various studies to be useful for decision-making.
It used a decision-making task for a rat in which some of the correct choices can be predicted, but others cannot.
The study found that only successful outcomes that can actually be predicted were robustly encoded over time. This finding was shown by analyzing complex interactions between three neurons.
Dr Balaguer-Ballester said: “The ‘coordinated noise’ between neurons contains information that the brain can use to guess whether is possible to anticipate the result of a choice or if its outcome is rather unpredictable.
“In other words, the degree of coordination between neurons contains information around whether there is any chance to envisage the result of a choice before taking it.
“However, this information is only present when responses of neurons are sufficiently coordinated not just in pairs, but they in a more complex and dynamic fashion, such as in groups of triplets.”
Dr Balaguer-Ballester added that the study is significant since it addresses several popular debates in neuroscience, challenging the idea that noise in responses of neurons impairs how the brain takes decisions.
“More broadly, it suggests that we can’t neglect more complex, three-way interactions in brain circuits, even when they just seem superfluous noise,” he said.
“We showed here that they contribute to understanding how the brain represents concepts that we use daily in our decision-making strategy - such as to anticipate if the outcome of a choice can be envisaged or not.”
The research was undertaken in collaboration with the Institute for Biomedical Research IDIBAPS and the University Pompeu Fabra, both in Barcelona, and Columbia University in New York.
