The largest cognitive systems will be optoelectronic

TL;DR

The paper argues that future large-scale cognitive systems will combine electronic and photonic technologies to enable efficient, system-wide information processing and integration across vast areas at high speeds.

Contribution

It presents a multidisciplinary argument supporting the integration of electronic and photonic devices for scalable cognitive systems, including physical and theoretical considerations.

Findings

Optoelectronic networks can connect areas equivalent to large data centers.

Such systems could achieve system-wide integration at 1 MHz.

At brain-like frequencies, they could span the Earth's surface.

Abstract

Electrons and photons offer complementary strengths for information processing. Photons are excellent for communication, while electrons are superior for computation and memory. Cognition requires distributed computation to be communicated across the system for information integration. We present reasoning from neuroscience, network theory, and device physics supporting the conjecture that large-scale cognitive systems will benefit from electronic devices performing synaptic, dendritic, and neuronal information processing operating in conjunction with photonic communication. On the chip scale, integrated dielectric waveguides enable fan-out to thousands of connections. On the system scale, fiber and free-space optics can be employed. The largest cognitive systems will be limited by the distance light can travel during the period of a network oscillation. We calculate that optoelectronic networks the area of a large data center ($10^5$\,m$^2$) will be capable of system-wide information integration at $1$\,MHz. At frequencies of cortex-wide integration in the human brain ($4$\,Hz, theta band), optoelectronic systems could integrate information across the surface of the earth.