Circuits of the Mind

by Valiant, Leslie G.

• ISBN13: 9780195089264
• ISBN10: 019508926X
• Format: Hardcover
• Copyright: 1994-11-24
• Publisher: Oxford University Press

Summary

In this groundbreaking work, computer scientist Leslie G. Valiant details a promising new computational approach to studying the intricate workings of the human brain. Focusing on the brain's enigmatic ability to quickly access a massive store of accumulated information during reasoning processes, the author asks how such feats are possible given the extreme constraints imposed by the brain's finite number of neurons, their limited speed of communication, and their restricted interconnectivity. Valiant proposes a "neuroidal model" that serves as a vehicle to explore these fascinating questions. While embracing the now classical theories of McCulloch and Pitts, the neuroidal model also accommodates state information in the neurons, more flexible timing mechanisms, a variety of assumptions about interconnectivity, and the possibility that different areas perform different functions. Programmable so that a wide range of algorithmic theories can be described and evaluated, the model provides a concrete computational language and a unified framework in which diverse cognitive phenomena--such as memory, learning, and reasoning--can be systematically and concurrently analyzed. Requiring no specialized knowledge, Circuits of the Mind masterfully offers an exciting new approach to brain science for students and researchers in computer science, neurobiology, neuroscience, artificial intelligence, and cognitive science.

Table of Contents

The Approach	1	(8)
Biological Constraints	9	(16)
Introduction	9	(2)
The Neocortex	11	(6)
Pyramidal Neurons	17	(8)
Computational Laws	25	(8)
Introduction	25	(4)
Three Sources of Complexity	29	(4)
Cognitive Functions	33	(16)
Introduction	33	(1)
Boolean Functions	34	(4)
Learning	38	(2)
The Nature of Concepts	40	(3)
Experimental Psychology	43	(6)
The Neuroidal Model	49	(14)
Programmable Models	49	(2)
Neuroids	51	(9)
Timing	60	(3)
Knowledge Representations	63	(16)
Positive Knowledge Representations	63	(3)
Vicinal Algorithms	66	(3)
Frontier Properties and Storing New Items	69	(4)
Frontier Properties and Associations	73	(2)
Hashing	75	(4)
Unsupervised Memorization	79	(10)
An Algorithm	79	(10)
Supervised Memorization	89	(10)
Introduction	89	(2)
A Simple Algorithm	91	(3)
A Second Algorithm	94	(5)
Supervised Inductive Learning	99	(22)
Introduction	99	(2)
Pac Learning	101	(4)
Learning Conjunctions	105	(5)
Learning Disjunctions	110	(3)
Learning Linear Threshold Functions	113	(8)
Correlational Learning	121	(6)
An Algorithm	121	(3)
Computing with Numerical Values	124	(3)
Objects and Relational Expressions	127	(18)
Multiple Object Scenes	127	(2)
Relations	129	(4)
Timed Conjunctions	133	(3)
Memorizing Expressions Containing Relations	136	(4)
Memorizing New Relations	140	(1)
Discussion	141	(4)
Systems Questions	145	(12)
Introduction	145	(1)
General Organizational Principles	146	(6)
Compatibility of Mechanisms	152	(5)
Reasoning	157	(22)
Introduction	157	(3)
Reflex Reasoning	160	(1)
Simple Reflex Reasoning	161	(8)
Compound Reflex Reasoning	169	(3)
Nonmonotonic Phenomena	172	(7)
More Detailed Neural Models	179	(24)
Implementing Vicinal Algorithms	179	(3)
A Laminar Model	182	(10)
A Columnar Model	192	(4)
Sparser Random Graphs	196	(3)
Another Columnar Model	199	(4)
Afterword	203	(6)
Notes	209	(6)
Exercises	215	(4)
References	219	(11)
Index of Notation	230	(5)
Index	235