In sum, it is as if cognitive science found itself in the same situation as biology a century ago: back then, evolution and genetics were both recognized but still uncorrelated scientifically. It is only later, when DNA, RNA and proteins were discovered, that these two levels became finally linked and united through the Modern Synthesis. In other terms, by elucidating the mesoscopic level of life's complex self-organization (molecular biology), macroscopic phenomena (heredity, speciation) could be explained on the basis of microscopic elements (atoms, molecules; Fig. a).

Generally, if x_i(t) denotes the time-varying potential of neuron i, the answer could lie in large dynamic groups { x₁(t), ..., x_n(t) } characterized by spike timing series { t₁¹, t₁², t₁³, ..., t_n¹, t_n², t_n³, ... }, which contain many high-order moments <x_i(t) x_j(t - τ_ij) x_k(t - τ_ik) ...>, typically combinations of synchronized groups (where delays τ_ij = 0) and waves or "rhythms" (where delays τ_ij > 0). Called spatiotemporal patterns (STPs), these reproducible correlations among electric signals must also be supported by underlying regular patterns of connectivity.

Similarly to proteins, STPs could then interact in several ways and assemble ("bind") at several levels, forming a hierarchy of composite structures from simpler ones, like "building blocks" of intelligent behavior (Bienenstock 1996). My own research goal is to outline a new theoretical framework for this type of complex mesoscopic neurodynamics with compositional properties. I have conducted different studies (see below) that all construe the cortical substrate of neuronal units and synaptic contacts as an "excitable medium" and have potential applications to of artificial systems in perceptual, linguistic or behavioral tasks. ← Less

We also postulate that synfire patterns might constitute the elementary components or "molecular building blocks" at the mesoscopic level of the mind's symbolic abilities (see Introduction above), in particular the faculty of compositionality at the core of linguistic and perceptual functions (Fig. b-d).

Under the influence of external stimuli, chain motifs dynamically bind into higher structural compositions characterized by complex modes of activity (spatiotemporal patterns; STPs). This model suggests that neocortex is another instance of a "self-made tapestry" (Ball 1999) showing pattern formation, as are many natural complex systems. ← Less

The goal of this study is to understand and reproduce how our cognitive system creates schemas and categories at the interface between vision and language (Regier 1996), in particular its ability to effortlessly map an infinite diversity of visual scenes onto a small set of grammatical elements (Fig. a). Through this challenge we seek to elucidate the fundamental transformation of continuous dynamical stimuli into discrete symbolic contents (Petitot 2003), or ontology, which is emblematic of human intelligence and will be crucial to a reunited, biologically inspired AI.

In summary, our work addresses the crucial cognitive mechanisms of spatial schematization and categorization at the interface between vision and language and anchors them to dynamical processes such as activity diffusion or wave propagation. ← Less