Fortunato Tito Arecchi

Complex phenomena and cognitive processes

The methods developed to recognize and control chaos and patterns can be extended to biological phenomena as e.g. cardiac and brain signals. The adaptive methods can not only be extended from discrete to continuous dynamical systems, but they can also control a delayed system. Now, the delayed feedback method corresponds to embedding a physical system with a small number of degrees of freedom into a space with a larger number of dimensions.
Hence, this appears as a good analogy of the cognitive strategy used in any perceptual task, whereby we build holistic perceptions upon partial information (think e.g. of a deteriorated photography).

2004-2009: A new type of chaotic behaviour, called HC (homoclinic chaos) consisting of spike trains separated by chaotic time intervals ,first observed in CO2 lasers, displays features common to bain neurons[334]. It has been demonstrated to display a high propensity to organise in large synchronized networks, hence it appears as the most plausible dynamical model for a neuron and for the build up of feature binding through the synchronization of large neuron arrays in the brain[336].
The replacement of a conventional meter performing a local measurement with a time code which requires a given duration to access a reliable perception raises the question of the fuzziness of perceptions truncated to shorter times, and this introduces a quantum uncertainty which seems to hint to the possibility of parallel fast computation in brain processes. Similar behavior has been observed in cell communications of plant roots[384].

2009-2017: Rather than tracing the individual neuron behavior, a collective way of describing cognitive tasks is by Bayes inference [357]. Bayes inference characterizes perceptual processes, whereby a sensorial input gives rise to an adequate motor reaction; it requires a pre-assigned algorithm. Perceptions occur in all brainy animals. On the contrary, in linguistic tasks, humans compare a piece of a text with a previous piece, recalled by the short-term memory. The comparison gives rise to a new algorithm, via a process called inverse Bayes[399].
The role of language vs. perception in decision tasks is being actively explored, as reported in the review[438].


[Cooperative effects in quantum optics]  [Photon statistics and laser fluctuations]  [Deterministic chaos in optics]  [Pattern formation in extended media]