After Phrenology: Neural reuse and the interactive brain by Michael L. Anderson

After Phrenology: Neural reuse and the interactive brain by Michael L. Anderson

Author:Michael L. Anderson [Anderson, Michael L.]
Language: eng
Format: azw3
Tags: Brain
ISBN: 9780262320689
Publisher: The MIT Press
Published: 2014-12-25T16:00:00+00:00

Watt’s centrifugal governor. As the flywheel spins, the weights move closer or further apart depending on the speed; this movement pulls on the throttle lever, changing the amount of steam driving the engine. The coupling between these parts ensures that the engine maintains a steady speed. Picture from the Wikipedia Commons, made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

In his 1995 paper van Gelder introduces the Watt governor as a candidate exemplar for modeling cognition by first describing the sort of solution it is not. For from a certain perspective it might seem natural to turn this control problem into a measurement problem: monitor the engine speed; when there is a discrepancy between actual and desired speed, measure the steam pressure; calculate the necessary change in steam pressure; calculate the required throttle valve adjustment; and make the adjustment. After all, if one knows what adjustment is required, making it is mechanically trivial; all the hard work is in knowing what adjustment is needed. Thus, one solution to this problem is to focus on building the right measuring and calculating devices. If this is the approach taken, then, as van Gelder writes:

There must be some physical device capable of actually carrying out each of these subtasks, and so we can think of the [imagined alternate] governor as incorporating a tachometer (for measuring the speed of the flywheel); a device for calculating the speed discrepancy, a steam pressure meter; a device for calculating the throttle valve adjustment; a throttle valve adjuster; and some kind of central executive to handle sequencing of operations. This conceptual breakdown of the components of the governor may even correspond to its actual breakdown; that is, each of these components may be implemented in a distinct, dedicated physical device. (van Gelder 1995, p. 348)

The reader will of course recognize this approach as analogous to that motivating CCTM in general and the symbol systems model in particular: given a control problem, start by measuring and recording the values of some relevant set of objective properties in the world and use these values to calculate the appropriate response. Adapting such a framework makes it natural to suppose that there might be dedicated (neural) devices for representing and calculating, and it becomes the job of cognitive neuroscience to identify and describe these components. As van Gelder puts it:

Perhaps the most central of the [imagined alternate] governor’s distinctive properties is its dependence on representation. Every aspect of its operation, as outlined above, deals with representation in some manner or another. The very first thing it does is measure its environment (the engine) to obtain a symbolic representation of current engine speed. It then performs a series of operations on this and other representations, resulting in an output representation, a symbolic specification of the alteration to be made in the throttle valve; this representation then causes the valve adjusting mechanism to make the corresponding change. … Finally, notice that the governor is homuncular in construction. Homuncularity


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