On the nature of minds, or: truth and consequences

Abstract

Are minds really dynamical or are they really symbolic? Because minds are bundles of computations, and because computation is always a matter of interpretation of one system by another, minds are necessarily symbolic. Because minds, along with everything else in the universe, are physical, and insofar as the laws of physics are dynamical, minds are necessarily dynamical systems. Thus, the short answer to the opening question is "yes." It makes sense to ask further whether some of the computations that constitute a human mind are constrained by functional, algorithmic, or implementational factors to be essentially of the discrete symbolic variety (even if they supervene on an apparently continuous dynamical substrate). I suggest that here too the answer is "yes" and discuss the need for such discrete, symbolic cognitive computations in communication-related tasks. On the nature of cognitionMinds are fundamentally computational phenomena (Turing, 1950;McCulloch, 1965;Marr, 1982;Minsky, 1985;Dennett, 1991;Metzinger, 2003;McDermott, 2001;Nilsson, 2006;Minsky, 2006). The distinguishing and still surprisingly widely underappreciated feature of the explanatory framework for cognition that rests on this insight is that it has no viable alternatives (Edelman, 2008).Consider the so-called lightness problem, which is typical of visual perception: light from a source whose intensity is not directly known to the perceiver falls onto a surface whose reflectance needs to be estimated. The only course of action available to the perceiver is to try and estimate both the intensity and the reflectance from the amount of light that enters the measurement device (an eye or a camera). The pertinent observation here is that the essence of the process of distinguishing dark from light surfaces under potentially variable illumination -no matter how that process is instantiated -is a computation. Specifically, it consists of the factorization of the number that represents the measured light quantity, whereby the source intensity and the surface reflectance that are multiplicatively confounded in the measurement are recovered (Edelman, 2008, p.8). 1 All other perceptual tasks can be given similarly explicit computational formulations. * Invited target article for the special issue of JETAI on Pluralism and the Future of Cognitive Science.1 How two unknowns can be recovered from a single measurement is an interesting question (Marr, 1982;Edelman, 2008) that is beside the point for the present discussion.1 Just as perception is inherently computational, so is action. As an example, consider the nature of the problem that is solved by a cat that jumps onto a table (Edelman, 2008, p.428). This problem consists of estimating the right amount of momentum that the cat must impart to itself -a momentum that would allow it to clear the table's near edge, yet would not send it sailing over the table to hit the wall on the far side. The cat's safe landing on the table indicates that its brain has successfully carried out a series of arithme...

Information Processing, Computation, and Cognition

“…There are two ways to defend (5). Some authors argue that everything is computational because describing something as computational is just one way of interpreting it, and everything can be interpreted that way [19,23]. We reject this interpretational pancomputationalism because it conflates computational modeling with computational explanation.…”

“…In other words, most of the natural information signals carry in real world environments is probabilistic: signals carry natural information to the effect that o is probably G, rather than natural information to the effect that, with nomic certainty, o is G. 23 Unlike the traditional (all-or-nothing) notion of natural information, this probabilistic notion of natural information is applicable to the sorts of signals studied by cognitive scientists. Organisms survive and reproduce by tuning themselves to reliable but imperfect correlations between internal variables and environmental stimuli, as well as between environmental stimuli and threats and opportunities.…”

“…To make sense of this connection, we need a notion of natural information according to which types of alarm 23 For a more precise and detailed theory of probabilistic information, see [36,37]. The probabilistic notion of information we employ includes all-or-nothing natural information-roughly, the natural information that o is G with certainty-as a special, limiting case.…”

Music and Cognitive Extension

“…Almost anything can be given a computational description (Stufflebeam, 1999;Edelman, 2008). Though it's possible that music perception can be modeled computationally, this does not necessarily imply that music perception is a wide computational system.…”

On Look-Ahead in Language: Navigating a Multitude of Familiar Paths

“…Note that the popular trick of declaring it all innate amounts to dodging the question rather than answering it (Putnam, 1967). 6 At the level that matters, language is "digital" (that is, defined over a set of discrete primitives) for reasons of computational tractability (Edelman, 2008b In one of the existing algorithms, a teacher (the designer) serves as an oracle that evaluates pieces of generated behavior and decides the fate of the rules that gave rise to them (Mäkinen and Systä, 2002). In another work, statecharts are synthesized from scenario-based requirements, themselves stated in a formal language (Harel et al, 2005).…”