Cortical Activity waves are the physical carriers of memory and thought

Abstract

Growing and propagating waves of neural activity are the natural resonant modes of synaptic energy. In a layered geometry typifying the mammalian cortex, a time delay (T) in inter-layer signals effectively controls the temporal and spatial frequencies of the waves. As a function of T, two very different types of wave can grow from ubiquitous noise. One is coherent, and its resonant spatial frequency increases with increasing T. However, further increase eventually leads to a discontinuous increase in both wavelength and temporal frequency. The result is a region of T values wherein two waves grow simultaneously and interfere in random fashion. This remarkable duality, whose origin is in the phase relations of the amplified waves, leads us to propose that coherent waves are instrumental in the retrieval of memory and random waves embody original thought.