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Saturday, June 19, 2010

Toward a Dialectical Theory of Human Tool Use


In this rather dense paper, the authors argue that humans have the ability to view body action as a problem to be solved - that it is precisely at this point that technical reasoning occurs. They argue that neither the computational nor ecological explanation of tool use is adequate, so they propose that affordance perception and technical reasoning work together in a dialectical way.

Clarification of terms: Affordance perception:
The affordances of the environment are what it offers the animal, what it provides or furnishes, either for good or ill … something that refers both to the environment and the animal in a way that no existing term does. It implies the complementarily of the animal and the environment.
Gerald Fritz, et al, expand on this basic definition from J.J. Gibson to generate this concept:
We extend Gibson’s ecological approach under acknowledgment of Neisser’s understanding that visual feature representation on various hierarchies of abstraction are mandatory to appropriately respond to environmental stimuli. We provide a refined concept on affordance perception by proposing (i) an interaction component (affordance recognition: recognizing relevant events in interaction via perceptual entities) and (ii) a predictive aspect (affordance cueing: predicting interaction via perceptual entities).
Their two references:
[1] J.J. Gibson, The Ecological Approach to Visual Perception, Boston, Houghton Mifflin, 1979.
[2] U. Neisser, Cognition and Reality. Principles and Implications of Cognitive Psychology, San Francisco, Freeman & Co., 1976.
Anyway - this is geeky material, but I find this kind of thing very interesting. The more we can understand how various realms of experience work together in forming our experience of the world.

The full article is freely available here as a PDF.

Reference:
Osiurak, F., Jarry, C. & Le Gall, D. (2010). Grasping the affordances, understanding the reasoning: toward a dialectical theory of human tool use. Psychological Review; 117(2):517-40.

Abstract:

One of the most exciting issues in psychology is what are the psychological mechanisms underlying human tool use? The computational approach assumes that the use of a tool (e.g., a hammer) requires the extraction of sensory information about object properties (heavy, rigid), which can then be translated into appropriate motor outputs (grasping, hammering). The ecological approach suggests that we do not perceive the properties of tools per se but what they afford (a heavy, rigid object affords pounding). This is the theory of affordances. In this article, we examine the potential of the computational view and the ecological view to account for human tool use. To anticipate our conclusions, neither of these approaches is likely to be satisfactory, notably because of their incapacity to resolve the issue of why humans spontaneously use tools. In response, we offer an original theoretical framework based on the idea that affordance perception and technical reasoning work together in a dialectical way. The thesis we defend here is that humans have the ability to view body action as a problem to be solved. And it is precisely at this point that technical reasoning occurs. But, even if the ability to do technical reasoning gives humans the illusion of constantly doing less (e.g., TV remote control), they are still forced to use body action – and to perceive affordances – to operate the product of the reasoning (pushing buttons with the fingers). This is the principle of dialectic.

INTRODUCTION
One of the most exciting issues in psychology is what are the psychological mechanisms underlying human tool use? Surprisingly, this question has received very little attention from psychologists (Johnson-Frey, 2004; Le Gall, 1992). A certain number of attempts have nevertheless been made to model how humans perform tool behaviour (referred to hereafter as the HOW issue). These attempts fall into two categories. The first category assumes that tools have no inherent meaning, and thus the meaning must be created internally and stored by the user. The other category assumes that tools have inherent meanings, which is detected and exploited by the user without mental calculation. Most attempts fall into the former category (e.g., Buxbaum, 2001; Rothi, Ochipa, & Heilman, 1991; Roy & Square, 1985; Yoon, Heinke, & Humphreys, 2002). They all are computational models, based on the core assumption that the use of a tool (e.g., a hammer) requires the extraction of sensory information about object properties (heavy, rigid), which can then be translated directly or indirectly1 into appropriate motor outputs (grasping, hammering). J.J. Gibson’s ecological approach to perception falls into the latter category. For J. J. Gibson (1979), we do not perceive the properties of tools but what they afford (a heavy, rigid object affords pounding). This is the theory of affordances.

Besides the question as to how humans perform tool behaviour, another important question concerns the specificity of human tool use. It has been pointed out that human tool use differs from that known to occur in non-humans in different ways. Only humans possess a vast repertoire of tool use skills (Johnson-Frey, 2007), make one tool to create another (McGrew, 1992) or spontaneously engage in object-object manipulations (K. R. Gibson, 1991). In broad terms, humans seem to have the capacity of spontaneously and almost systematically use tools so as to modify their way of interacting with the world, a feature which characterizes humans of all cultures through the ages (Leroi-Gourhan, 1971, 1973). For instance, humans use horses, bicycles, cars, boats or aeroplanes to move. Likewise, they use spears, traps, guns, and bows to hunt, or rucksacks, baskets, jags, cans and heavy goods vehicle to transport things. In fact, the relationship existing between humans and the environment is constantly changing, a specificity which is much more visible at the species level through the technical evolution. Just think about what the place where you grew up looks like now (kitchen utensils, household equipment, TV sets, computers, street equipment, cars, houses, and so on), and you will have a pretty good snapshot of it. So, to be complete, any theory that is supposed to describe the mental mechanisms of human tool use must not only address the HOW issue, but should also be concerned with the question as to why do humans spontaneously use tools? (Referred to hereafter as the WHY issue)

The purpose of the paper is threefold. Firstly, we address two tricky epistemological issues concerning tool use. The first one is what a tool is? Most papers on the topic do not define precisely what they mean by “tool use”, probably because they view tool behaviour as something obvious. Through this work, we wish to emphasize that tool behaviour is anything but obvious, however. The second is what does it mean to consider two behaviours to be analogous? A growing body of literature has described observations of tool use in a wide range of species. It is worth emphasizing that some reports in a species arise from a single individual on one occasion or only from observations in captivity (Beck, 1980; see also Chappell & Kacelnik, 2002). This contrasts markedly with the use of tools by humans which is very spontaneous and frequent. So, the question arises as to which extent tool use by humans and non-humans can be considered analogous.

The second purpose is to examine the potential of the computational view and the ecological view to account for human tool use. To anticipate our conclusions, neither of these approaches is likely to be satisfactory because of their incapacity to resolve the WHY issue. Nevertheless, with regard to the HOW issue, the ecological approach provides a better account of the perception of the relationships between an organism and the environment, notably by stressing that perception is “designed” for action.

In response, we offer an original theoretical framework based on the idea that affordance perception and technical reasoning work together in a dialectical way and this is the third purpose of this paper. Briefly, the thesis we defend here is that humans have the ability to view body action as a problem to be solved. And it is precisely at this point that technical reasoning occurs. But, even if the ability to do technical reasoning gives humans the illusion of constantly doing less (e.g., TV remote control), they are still forced to use body action – and to perceive affordances – to operate the product of the reasoning (pushing buttons with the fingers). This is the principle of dialectic. The dialectical theory of human tool use we propose here is inspired by the theory of affordances (J. J. Gibson, 1979) as well as the work of Gagnepain (1990) on the dialectical functioning of the human mind.
Read the whole article (PDF).

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