Key to good planning may lie deep in the brain's amygdala

Thinking of a new career? Buying a home? Have you consulted your amygdala?

These almond-shaped clusters of neurons deep in the brain may play a vital part in long-term planning, says a new study.

Experiments conducted on lab monkey amygdala may also help the search for treatments for drug addiction, binge eating and other human behavioural problems, its authors hope.

Scientists led by Fabian Grabenhorst at Britain's University of Cambridge wanted to see how the amygdala - the organ comprising cell clusters in the brain's temporal lobes - contributes to long-term planning. The amygdala has long been associated with primal, short-term drivers like fear and aggression, but also with behaviour linked to reward.

Two monkeys were put through an experiment in which they were trained to choose between accepting an immediate fruit juice reward, or wait and receive a bigger dose later. The more they restrained themselves, the bigger the reward grew - and like shrewd investors, both monkeys tended to save up.

The team implanted electrodes in the monkeys' brains to observe the decision-making sequence. Early in the process, neurons in the amygdala were activated in a pattern that reflected "several trials ahead" whether the monkey would save up towards specific goals.