The term ‘scientific model’ usually refers to conceptual or computer models, not tangible physical structures. One famous episode in science which did involve tangible models was the 1953 discovery by Crick and Watson of the double-helix structure of DNA. Their rod-and-ball constructions, ‘which looked like Tinker Toys gone crazy’ (Depew and Weber 1995, 346), enabled them to ‘scoop’ Rosalyn Franklin, from whom they extracted crucial information leading to the discovery. ‘Unlike Franklin, who would otherwise have been in a good position to deduce DNA’s structure, they were not patient enough to be empiricists’ (Depew and Weber 1995, 345). In other words they used the abductive logic of guess-and-modify rather than the inductive logic of starting with the evidence and methodically building the theory from that ground up; and abductive logic is often facilitated by working with models which are visible (if not tangible). But like all models, the Watson-Crick model greatly simplified the reality, which is far more dynamic, fluctuating at several different time scales (Pagels 1988, 107).
The same is true of anyone’s internal model of the world one has to navigate. When we said in Chapter 3 that ‘map’ is a misleading word because the world in which an animal moves is multidimensional, even that was a gross understatement; see Llinás (2001, Chapter 2) on the ‘dimensionality of the problem of motor control’ (26). In the same chapter, Llinás explains guidance systems in a way quite similar to Varela’s ‘enactive’ model (as outlined in the Chapter 9). ‘The brain’s control of organized movement gave birth to the generation and nature of the mind’ (50); ‘that which we call thinking is the evolutionary internalization of movement’ (35). In the Llinás model, the ‘8-12 Hz rhythmicity of physiological tremor’ (31) acts as the ‘clock’ which enables synchronization of movement. All movement is a modulation of this ever-present ‘tremor,’ which is its material cause; when the organism reacts to external events, sensory input is the efficient cause. But an organism can also initiate movement proactively.
As emphasized in Chapter 10, it should be clear in our reading of the meaning-cycle diagram ‘that the flow from M to W is simultaneous with the flow from W to M. There is only one flow, not two taking turns.’ Within the brain, the functional unity of action and perception is embodied in ‘mirror neurons’ and in the
class of neurons in the frontal lobes called canonical neurons.… Like mirror neurons, each canonical neuron fires during the performance of a specific action such as reaching for a vertical twig or an apple. But the same neuron will also fire at the mere sight of a twig or an apple. In other words, it is as though the abstract property of graspability were being encoded as an intrinsic aspect of the object’s visual shape. The distinction between perception and action exists in our ordinary language, but it is one that the brain evidently doesn’t always respect.
— Ramachandran 2011 (Kindle Locations 938-943)