A new perspective on the organization of an invertebrate brain.

The concept of 'embodiment' and its implications for the evolution of cognitive capacities is emerging as a major issue in biology. Invertebrates have immensely diverse nervous structures and body plans, revealing the variety of solutions evolved by animals living successfully in all kinds of niches. Among invertebrates, the octopus is a special case because of its high cognitive abilities and a uniquely flexible body and manoeuvrable arms with virtually infinite degrees of freedom. Here we discuss how the octopus embodiment may be considered a 'key' to the development of its neural organisation and cognitive abilities.