Lecture 14: Gestaltism II: Fields, Self-Organization, and the Invariance Postulate of Evolution (Turvey, 2019, Lectures on Perception)

In the previous Lecture, Turvey discussed the machine metaphor in which things are just equal to the sum of their parts. In this Lecture, Turvey introduces the Gestalt notion that wholes are different from the sum of their parts. Well, specifically, he discusses the notions of fields and self-organisation, and the kinds of physical systems that these entail; Gestalt psychology is mostly just a launching pad for the broader discussion. 

Turvey discusses first the notion of a field in physics. Fields are how physics explains action at a distance such as magnetism; the magnetic object produces a field around it that extends into space and interacts with other magnetic fields. Magnetism is the details of what happens when those fields interact (the objects may attract or repel each other). Fields are how objects exert influence over apparently empty distances. Fields feature prominently in Gestalt psychology (neural fields, behavioural fields, life-space fields), in part because of the prominence they had acquired in physics (e.g. Faraday). 

Within this approach, the order seen in behaviour is not the product of anatomy (as discussed in Lecture 13) but of dynamics. The behaviour of all systems, animate and inanimate, emerges as the relevant physics unfolds over time in an interaction-dominant fashion, vs. a component-dominant way (see Lecture 12 and the idea of epigenesis). The Gestaltists referred to this as the invariance postulate of evolution, which is just the idea that biology must be built out of and follow the rules of the laws of dynamics/physics. Evolution is a special case, a set of particular constraints on a particular class of physical system (open, rather than closed or isolated). (I'll just note here that Turvey was very into deriving things so as to be consistent with physics; e.g. Turvey & Carello, 2012).

Overall, the point of this lecture is to discuss the notion of fields, and to note that the Gestalt psychologists were the first to start bring this new approach to physics into the study of behaviour. Fields come from a non-machine approach to physics, one focused on interactions and process and change vs. static components acting on each other. We are starting to encounter the new physics needed to move away from the Cartesian programme.