How brain creates sequences revealed

Researchers aiming to find how separate small elements come together to become a unique and meaningful sequence, have found that a specific area of the brain, the basal ganglia, is implicated in a mechanism called chunking, which allows the brain to efficiently organize memories and actions.

Neuroscientist Rui Costa, and his postdoctoral fellow, Fatuel Tecuapetla, both working at the Champalimaud Neuroscience Programme (CNP) in Lisbon, Portugal, and Xin Jin, an investigator at the Salk Institute, in San Diego, USA, reveal that neurons in the basal ganglia can signal the concatenation of individual elements into a behavioural sequence.

"We trained mice to perform gradually faster sequences of lever presses, similar to a person who is learning to play a piano piece at an increasingly fast pace. By recording the neural activity in the basal ganglia during this task we found neurons that seem to treat a whole sequence of actions as a single behavior," Costa explained.

The basal ganglia encompass two major pathways, the direct and the indirect pathways. The authors found that although activity in these pathways was similar during the initiation of movement, it was rather different during the execution of a behavioural sequence.

The study was published in the journal Nature Neuroscience.