How cuttlefish wear their thoughts on their skin

Studying the neural basis of perception is tricky, but what if the output of that neural activity were on display? That, says Sam Reiter and his team from The Max-Planck Institute for Brain research, is precisely what cuttlefish do. Cuttlefish have the ability to alter their appearance using finely controlled colour-changing cells in their skin. These cells are directly controlled by neurons extending from the brain. The team monitored changes in the state of the colour-changing cells with high-resolution cameras, which allows them to track the activity of tens of thousands of neurons simultaneously, for the first time.