Crayfish Comes As an Excellent, Practical Model for Insight into Human Decision Making

University of Maryland researchers headed by Dr Jens Herberholz, have come to the conclusion that Crayfish make surprisingly complex, cost-benefit calculations and this may help unravel the cellular brain activity involved in human decisions. Their study is the first to isolate individual crayfish neurons involved in value-based decisions. According to the researchers matching individual neurons to the decision making processes in the human brain is simply impractical for the time being now. The happy news is that basic organization of neurons and the underlying neurochemistry are similar, involving serotonin and dopamine.

In the experiments Crayfish was offered a choice between finding their next meal and becoming a meal for an apparent predator.  Dr Herberholz says the fish carefully weighed the risk of attack against the expected reward.

To make a quick escape, the crayfish would flip their tails and swim backwards. This action was preceded by a strong, measurable electric neural impulse. Specific neurons that come in to play during the decision-making process were identified. The fish take the action in a matter of milliseconds.

When the predator appears to be moving too rapidly for escape the crayfish chose to freeze.

The research has shown that crayfish, similar to organisms of higher complexity, integrate different sensory stimuli that are present in their environment, and they select a behavioural output according to the current values for each choice.

Details of the study appear in online edition of Proceedings of the Royal Society B.