Olivier Georgeon's research blog—also known as the story of little Ernest, the developmental agent.

Keywords: situated cognition, constructivist learning, intrinsic motivation, bottom-up self-programming, individuation, theory of enaction, developmental learning, artificial sense-making, biologically inspired cognitive architectures, agnostic agents (without ontological assumptions about the environment).

Sunday, December 7, 2008

Review of Sun R. (2004)

Sun, Ron (2004). Desiderata for cognitive architectures. Philosophical Psychology, Vol.17, No.3, pp.341-373.

I wrote this review because I think this paper gives valuable arguments in favor of the approach I have chosen with Ernest.

It starts with a nice presentation of what cognitive architectures are: "a concrete framework for detailed modeling of cognitive phenomena, based on a specification of essential structures". This presentation, however, points out that there is no clear consensus about what these essential structures should be. This lack of consensus has given raise to many different cognitive architectures which are difficult to assess and compare. The paper reviews ACT-R, Soar, EPIC, COGNET, CLARION.

Ron Sun discusses this lack of consensus with many regard. For example, many dichotomies have been proposed with regard to memory: short-term memory/working memory/long-term memory, implicit memory/explicit memory, procedural memory/ declarative memory, etc. Ron Sun concludes that “it is far from clear what essential subsystems of memory are, and thus, how memory should be divided”. Moreover, it is not even sure that memory itself can be seen as a differentiated module from the rest of cognition: “Memory is not simply retention, but it is also pretentions, as pointed out by Husserl (1970); that is, it actively participates in intercepting the on-going flow of sensory information and it itself changes and organizes in the process”.

In this situation, Ron Sun advocates a minimalist approach of cognitive architecture, and enounces a list of basic desiderata:
  • Ecological realism: account for essential cognitive functions in a natural environment.
  • Bio-evolutionary realism: human models should be reducible to animal models, because of a continuum between animals and humans.
  • Cognitive realism: capture essential characteristics, abstract away from details of voluminous data.
  • Reactivity: account for fast response which does not involve elaborated computation.
  • Sequentiality: account for ability to recognize temporal dependencies.
  • Routiness: “Overall, we may view human everyday activities as consisting of forming, changing, and following routines”. “The initiation of routines (e.g. setting goals), the routines themselves, and the termination of routines can all be learned, in addition to being pre-wired using pre-determined rules. Routines (and their initiation and termination) may be learned through experience, including autonomous exploration, instructions, imitations, extraction, and other means”.
  • Trial and error adaptation: “learning of reactive routines is mostly, and essentially, a trial-and-error adaptation process. There are reasons to believe that this kind of learning is the most essential to human everyday activities and cognition”.
  • Bottom-up learning: “concerns how complex reasoning can arise from the simplest adaptive behavior, how abstract concepts can be based on simple, concrete reactive actions patterns, how consciousness can emerge from unconsciousness, and so on”. Moreover, “Buttom-up learning enables conceptual structures of an agent to be grounded in both the subsymbolic processes of the agent as well as the interactions between the agent and the world”.
  • Modularity: Ron Sun proposes that the two basic modules of a cognitive architecture should be an implicit module and an explicit module. According to him, such an architecture would meet this whole desiderata list. Among the architectures he reviews, only CLARION (his own architecture) implements this modularity.

Ron Sun grounds his argumentation on phenomenological philosophy. He refers to Heidegger (1927) for the idea that behavior is prior to representation: “Comportment, according to Heidegger, "makes possible every intentional relation to beings" and "precedes every possible mode of activity in general", prior to explicit beliefs, prior to explicit knowledge, prior to explicit conceptual thinking, and even prior to explicit desire. Comportment is thus primary, in exactly this sense. The traditional mistake of representationalism lied in the fact that they treat explicit knowledge and its correlates as the most basic instead, and thus they turn the priority upside-down: and in so doing, "every act of directing oneself toward something receives [wrongly] the characteristics of knowing".

Ron Sun acknowledges that “Conceptual thinking has important roles to play too in cognition”, but he states that “Conceptual thinking is "derived" from low-level mechanisms, because it is secondary in several (radically different but related) senses: evolutionarily, phylogenetically, ontogenetically (developmentally) and ontologically.”

Thus, Ron Sun insists on the need to focus more on the interaction between a cognitive agent and his world, and amongst cognitive agents. “What we need to do to gain a better understanding of comportment [...] is to look into the development of comportment […]. In particular, we should examine its development in the ontogenesis of individual agents, which is the most important means by which an agent develops its subconceptual behavioral routines or comportments, although some of the structures (such as modularity) might be formed evolutionarily, a priori, as discussed before.”

I believe my work follows the directions suggested in this paper because I am focusing on the interaction between an agent and his environment, and implementing buttom-up learning mechanisms from this interaction. My only regret about this paper is that I don’t think it is totally fair with other cognitive architectures than CLARION. I think the dichotomy between implicit and explicit depends on the viewpoint from which we look at it, and thus, I am not sure this dichotomy must be implemented in the cognitive architecture itself. Soar is generally considered as an explicit representationalist approach of cognition, but I can use it to model implicitly-controled behavior. I think this representationalist assumption, on which Soar is based, might even facilitate the implementation of the bottom-up learning of explicit knowledge from implicit know-how.


Hidegger, M. (1927). Being and Time. English translation published by Harper and Row, New York. 1962.