Seminar by Alessandra Lucchetti

Investigation of neural synchronization and chimera states: resonators vs integrators

Alessandra Lucchetti (NBI)

Collective synchronization is an ubiquitous phenomenon in nature. It occurs at many different levels of biological organization, from the synchronous flashing in swarms of fireflies, to cardiac pacemaker cells, to the firing of neural cells in the brain. In particular, neuronal synchronization eventually produces oscillations in the average electrical activity known as brainwaves. Synchrony is not always a good thing, though. In Parkinson’s disease an aberrant version of a normal oscillatory activity presumably arises as a result of an enhanced negative feedback loop; this is believed to correlate with the emergence of motor symptoms such as rigidity and slowness of movement.

Inspired by this context, I will describe how to predict the emergence of collective synchronization in a negative feedback loop, by making use of phase models. Moreover, I will show that a remarkable phenomenon known as a “chimera state” can occur with identical oscillators when modelled as integrators (as opposed to resonators) coupled in a negative feedback loop with delayed connections.