Research suggests brain activity fluctuations impact risk-taking

Spontaneous fluctuations in human brain activity influence whether people make risky decisions, a new study has suggested.

Scientists say the minute-to-minute changes, linked to dopamine levels, could explain why people are inconsistent and sometimes irrational.

Published in the Proceedings of the National Academy of Sciences, the study indicates human behavioural variability may not be random, but instead linked to internal brain states.

Co-lead author Dr Tobias Hauser, of University College London’s Queen Square Institute of Neurology, said: “Experts have long struggled to explain why people are so erratic, making one decision one day and the opposite decision another day.

“We know that the brain is constantly active, even when we aren’t doing anything, so we wondered if this background activity affects our decisionmaking.

“It appears that our inconsistent behaviour is partly explained by what our brain is doing when we are doing nothing.”

Researchers focused on people who were in a state of rest – awake but not doing anything.

While at rest, the brain remains active with strong fluctuations in activity that remain unexplained.

For the study, 43 people completed a gambling task while in an MRI scanner.

Scientists monitored activity in the area of the brain containing most of the dopamine neurons.

Dopamine is a neurotransmitter and is known to play a role in risky decisionmaking.