Sunday, 16 April 2017

Flynn’s Cat – Part 3: An Exploration of Embodiment


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< Flynn's Cat - Part 2 

Radical embodiment theorists are the most openly opposed to traditional cognitive science.  It aims to replace traditional methods and concepts, with new foundations that incorporate emergent outcomes of dynamical systems and sense-act interactions between a body and the world it is engulfed in. In this approach, inspired in part by Gibson’s (1966) continuous interactions between an organism and its environment, computational models can never be adequate, as cognition is a continuous thing, and the body and its nervous system are in the world, so there is no need to represent them. 

Dynamical systems with their state space (a map of all possible states), certainly have explanatory power. The state space for the cat would presumably be all possible positions and movements that she could assume and her evolution would be in the form of differential equations. According to this view, cognition emerges from the dynamical interaction of the cat’s brain activity, the activities in her body and her environment. In other words, a neural mechanism in a certain sort of body, in a certain sort of environment will produce behaviours that dynamical systems equations can describe.
The physical properties of the cat such as the connection between her muscles and her ligaments offer enlightenment of what she does and how she operates. How she walks, for example, is the product of dynamical interactions between her muscles and other anatomical parts and the surfaces she walks on.  In some ways, she is like a behaviour-based robot where the behaviour of each part is a response to a sensor activity that when combined emerges into an overall behaviour that appears to me, the observer, a coherent behaviour, and it is only I, as an observer that imputes a central representation of what she is, or is doing. When compared to Shakey the robot, which exemplifies the thinking within traditional cognitive science, there is no internal model or general purpose programming. Instead the cat is tightly connected to the world in an uninterrupted way and a sensory system that leads directly to behaviour.

Because her brain is situated, she can use the physical and functional organisation of the space around her to offload her cognitive processing to her environment. She might also exhibit trajectories of state from any state she might hold toward an attractor. It is not so obvious what this attractor might be in a cat as opposed to a pendulum, but presumably it would be a stillness.  She has a pattern on her fur which may hold the self-organising or emergent properties of her genetic line.

And then there’s our relationship. Are we coupled in some way that displays a cyclical pattern of causal events; a higher order pattern that influences a lower order pattern that maintains the higher order pattern. As I stroke her, she physically moves in response, which entices me to continue stroking her. Like Watt’s Centrifugal Governor, the components of the system are continuously moving. She keeps me company, so I feed her, which entices her to stay with me. 

However, the sheer complexity of the cat’s dynamical equations aside, do they describe how the system changes, rather than why it changes? In other words, are they descriptive rather than explanatory? Perhaps not. An equation that describes the acceleration in her movements might explain why she is moving at a particular velocity at a particular moment in time. In this way, the equations might predict her velocity in the next instant or why she is in a particular state given her previous state.

So, dynamical systems theory can certainly be used to describe both the cat herself and her relationship with me.  The ability to apply dynamical systems theory to the brain, the body and the world, brings a unified approach that traditional cognitive science does not. Differential equations can be used to explain what goes on inside and outside the body, but does it extend to all aspects of cognition? This is the topic of my last post...

Flynn's Cat - Part 4 > 

References
Gibson, J.J. (1966). The senses considered as perceptual systems. Oxford, England: Houghton Mifflin

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