Parsimony, exhaustivity and balanced detection in neocortex
Résumé
The layout of sensory brain areas is thought to subtend perception. The principles shaping
these architectures and their role in information processing are still poorly understood.We
investigate mathematically and computationally the representation of orientation and spatial
frequency in cat primary visual cortex. We prove that two natural principles, local exhaustivity
and parsimony of representation, would constrain the orientation and spatial frequency
maps to display a very specific pinwheel-dipole singularity. This is particularly interesting
since recent experimental evidences show a dipolar structures of the spatial frequency map
co-localized with pinwheels in cat. These structures have important properties on information
processing capabilities. In particular, we show using a computational model of visual
information processing that this architecture allows a trade-off in the local detection of orientation
and spatial frequency, but this property occurs for spatial frequency selectivity
sharper than reported in the literature. We validated this sharpening on high-resolution optical
imaging experimental data. These results shed new light on the principles at play in the
emergence of functional architecture of cortical maps, as well as their potential role in processing
information.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers éditeurs autorisés sur une archive ouverte