Sensory Selectivity in Random Cortical Circuits

Recent experiments indicate that primary auditory and visual cortex in rodents exhibit '"Salt and Pepper" architecture, consisting of highly selective neurons without columnar structure. Likewise, there is no apparent functional structure in the pattern of projections from the olfactory bulb to piriform cortex. In my talk I will address the questions: Can sharp stimulus selectivity be maintained in a cortical circuit with random connections? What are the computational ramifications of random cortical projections? How moderate tuning of cortical connectivity can be incorporated on top of largely random architecture? I will describe recent theoretical work that addresses these questions and will discuss their applications to sensory processing in rodent visual and olfactory cortices.  I will also discuss relation between these results and recent developments in Machine Learning.