Unified Theories of Cognition
Unified Theories of Cognition is a 1990 book by Allen Newell.[1] Newell argues for the need of a set of general assumptions for cognitive models that account for all of cognition: a unified theory of cognition, or cognitive architecture. The research started by Newell on unified theories of cognition represents a crucial element of divergence with respect to the vision of his long-term collaborator, and AI pioneer, Herbert Simon for what concerns the future of artificial intelligence research. Antonio Lieto recently drew attention to such a discrepancy,[2] by pointing out that Herbert Simon decided to focus on the construction of single simulative programs (or microtheories/"middle-range" theories) that were considered a sufficient mean to enable the generalisation of “unifying” theories of cognition (i.e. according to Simon the "unification" was assumed to be derivable from a body of qualitative generalizations coming from the study of individual simulative programs). Newell, on the other hand, didn’t consider the construction of single simulative microtheories a sufficient mean to enable the generalisation of “unifying” theories of cognition and, in fact, started the enterprise of studying and developing integrated and multi-tasking intelligence via cognitive architectures that would have led to the development of the Soar.
Contents
    
Newell argues that the mind functions as a single system. He also claims the established cognitive models are vastly underdetermined by experimental data. By cognition, Newell means:
- Problem solving, decision making, routine action
 - Memory, learning, skill
 - Perception, motor behavior
 - Language
 - Motivation, emotion
 - Imagining, dreaming, daydreaming
 
After arguing in favor of the development of unified theories of cognition, Newell puts forward a list of constraints to any unified theory, in that a theory should explain how a mind does the following:
- Behave flexibly as a function of the environment
 - Exhibit adaptive (rational, goal-oriented) behavior
 - Operate in real time
 - Operate in a rich, complex, detailed environment (Perceive an immense amount of changing detail; use vast amounts of knowledge; and control a motor system of many degrees of freedom)
 - Use symbols and abstractions
 - Use language, both natural and artificial
 - Learn from the environment and from experience
 - Acquire capabilities through development
 - Operate autonomously, but within a social community
 - Be self-aware and have a sense of self
 - Be realizable as a neural system
 - Be construable by an embryological growth process
 - Arise through evolution
 
Newell's secondary task is to put forward the cognitive architecture Soar as an implementation of a UTC that meets the constraints above. Other efforts at unified theories of cognition cited in the book include ACT-R and the human processor model.
See also
    
    
References
    
- Newell, Allen. 1990. Unified Theories of Cognition. Harvard University Press, Cambridge, Massachusetts.
 - Lieto, Antonio (2021). Cognitive Design for Artificial Minds. London, UK: Routledge, Taylor & Francis. ISBN 9781138207929.
 
Further reading
    
- Newell, A. (1994).Unified Theories of Cognition, Harvard University Press; Reprint edition, ISBN 0-674-92101-1.
 - Newell, A. (1973). "You can’t play 20 questions with nature and win: Projective comments on the papers of this symposium". In W. G. Chase (ed.), Visual Information Processing. New York: Academic Press. (Read article online.)