Perception, Imagery, and the Sensorimotor Loop

I wish I knew about this at the beginning of my rehab. It should have available to my unknowing PMR doctor since this is from 1995,1997.

Perception, Imagery, and the Sensorimotor Loop

Abstract:

I have argued elsewhere that imagery and represention are best explained as the result of operations

of neurally implemented emulators of an agent's body and environment.

1

In this article I extend the

theory of emulation to address perceptual processing as well. The key notion will be that of an

emulator of an agent's

egocentric behavioral space

. This emulator, when run off-line, produces

mental imagery, including transformations such as visual image rotations. However, while on-line,

it is used to process information from sensory systems, resulting in perception (in this regard, the

theory is similar to that proposed by Kosslyn (1994)). This emulator is what provides the

theory

in theory-laden perception. I close by arguing briefly that the spatial character of perception is to be

explained as the contribution of the egocentric behavioral space emulator.

0. Introduction.

The intuitive link between perception and imagery is currently being vindicated. There is increasing

neuropsychological evidence demonstrating that many of the same cortical areas, including primary

sensory areas, are involved in both processes. While this may be more exciting than it is

surprising, it is surely surprising to many that most types of imagery also involve increased activity

in cortical and cerebellar structures primarily concerned with

motor control

. Much of this article

will be aimed at explaining how and why motor areas and sensory areas interact so as to produce

imagery. The lessons of this hypothesis stretch far beyond a simple explanation of the

neurobiological foundations of imagery to shed significant light on the nature perception,

cognition, representation, and ultimately, conscious experience itself. Dealing with all of these

would obviously be unrealistic, so I shall limit my ambitions to some remarks on perception.

This article will be organized as follows. Section 1 will briefly introduce an architecture for

biological motor control. I will then explain how this motor control architecture, with trivial

modifications, can provide for motor imagery. This hypothesis leads to certain predictions about

the relationship between motor performance and imagery. Section 2 recounts psychological and

neurobiological evidence to the effect that these predictions are borne out. Section 3 generalizes the

framework to cover visual imagery, and then quickly runs through some of the evidence that visual

imagery is best explained by the same mechanisms. Finally, Section 4 applies this framework to

the issue of perceptual processing, and especially the spatial character of perceptual experience.