Granger, R (2006). Essential circuits of cognition: The brain's basic operations, architecture and representations.

Granger R.

Introduction

The goals of artificial intelligence have always been twofold: i) formal explanation of the mechanisms underlying human (and animal) intelligence and ii) construction of powerful intelligent artifacts based on those mechanisms. The latter engineering goal may pragmatically benefit from the former scientific one: extant face recognition systems and automated telephone operators might have been considered the best possible mechanisms were it not for our own abilities. The only reason that we know that these industrial systems can be outperformed is that humans do so.

Biological systems achieve their cognitive capabilities solely through brain mechanisms: the physiological operation of anatomical circuitries. Brain circuits are circuits; that is, they can be understood in computational terms. An explosion of knowledge in neuroscience and related fields is revealing the data crucial for characterizing the layout and properties of these circuits. For purposes of artificial intelligence, this information can be organized into three key topics:

• basic operations: what are the elemental operators carrying out fundamental mental steps?

• architecture: in what organizational control structure are the operators embedded?

• representation: how are memories and knowledge structured, stored, and retrieved?

Not one of these questions is yet answered. But findings from a range of fields including anatomy, physiology, plasticity, pharmacology, and neuroimaging, enable formulation of strict and interlocking constraints on the space of admissible answers. The ensuing review will discuss key findings that provide such constraints, and will point to publications in the primary literature offering further background on these topics.

Richard Granger