The organization of action: A new synthesis

by Charles R. Gallistel

A synthesis of classic and modern neurobehavioral literature dealing with the principles by which complex, purposive, and intelligent behavior is generated, this book* papers by C.S. Sherrington, E. von Holst, D.M. Wilson, G. Fraenkel, H. Mittelstaedt, and P. Weiss* clear descriptions of three types of elementary units of behavior -- the reflex, the oscillator, and the servomechanism* a review of the diverse manifestations of hierarchical structure in the neural mechanisms underlying coordinated action.This volume has proven to be of great value to psychologists, neurobiologists, and philosophers interested in the problem of action and how it may be approached in light of modern neurobehavioral research. It has been designed for use as a supplemental text in courses in physiological psychology, neurobiology and behavior, and those courses in cognitive and developmental psychology that place particular emphasis on understanding how complex behavior patterns are implemented.

432 pages, Hardcover

First published April 2, 1980

Reviews

[Konstantin Ivanovitch · Rating 3 out of 5]

This is a decent introductory text for a graduate student beginning in the neurosciences. Even though it is over 40 years old, it still would likely provide more of a foundational primer in how to think about animal behavior than any official graduate program curriculum. The main reason the book achieves this is simply because it emphasizes an important theme for thinking about brain function: the servomechanism. This is a concept that is not well understood in neuroscience and so is not readily taught – it took me years of self-guided study to come to understand it. A servomotor is a device that maintains a specified position. The device uses energy to actively keep and hold that position in a continuous manner. The mechanism contains a sensor that reads its position at each moment and compares that value with the specified position value. Any difference between the commanded value and the current value results in a movement of the motor until the difference is 0. This is called negative feedback control. Built in to the servo mechanism is a way to change the specified position.

Like with many inventions by humans, the servo was invented to replace or mimic some basic function - there is a lot of evidence that the brain operates using servomechanisms, but these properties are not well taught in our neuroscience programs. Most neuroscience students would not be able to explain what a servo is or how it applies to behavior. Gallistel’s book – even though it is quite old – is useful for making this kind of introduction. However, the mistake that Gallistel makes is that he only considers the servomechanism as only one of several basic principles that are key to understanding behavior. He fails to recognize that the servomechanism is the only fundamental property of the nervous system upon which all other processes are constructed upon and emerge from.

A good example of this is his distinction between the servomechanism and the reflex. The reflex was originally described by Sherrington whereby muscle contraction could be evoked using a stretch in the tendon – reflexes have to this day been considered ‘the elementary unit of behavior’. This is where the book makes a grave error and can mislead students – what Gallistel fails to articulate or understand is that reflexes are special features of the operation of servomechanisms, and not just additional independent functions of the brain. For example, Sherrington’s preparations required the removal of the brain in order to have reliable effects. The consequences of such brain removal is that the commands to the servomechanisms are put to extreme values – 0. The sensitivity of these systems to external perturbations (the stimuli in Sherrington’s experiments) would be massively heightened, making it appear that the stimulations would produce the resulting responses. In fact, these events occur because of the particular conditions of the preparations that reflect the operation of servomechanisms under unique, unnatural conditions. This basic misunderstanding results in many errors and simplifications that reflect the lack of understanding that Gallistel has about the servomechanism.

By choosing to focus on the studies on the sea snail by Fraenkel, the book doesn’t really communicate the importance of the servomechanism to all behavior, but rather only conveys to the reader that these are special fancies in the wild that don’t have much relevance in systems neuroscience. While I think that the book has a lot of value in its introduction of the hierarchical organization of the brain, chapter 8 is full of diagrams that show that very little is understood about this organization. For example, entirely missing is an articulation of the way that feedback influences the operation of these hierarchically organized systems – the sensory components of these systems is not included in the discussion or the diagrams. This results in a generally superficial lesson that does not help move students away from the mainstream ways of thinking about the brain: that it controls output in a feedforward manner.

In addition, the author relies extensively on the terms ‘potentiation’ and ‘depotentiation’ to explain how complex organismic levels of behavior may work. This is a good example of circular thinking – words that describe the observed phenomenon are then also used to describe the proposed mechanism for that phenomenon: Potentiation means behavior is likely to be observed at the expense of other behaviors. I think that Gallistel fails to make the connections between his servomechanisms and oscillators to explaining the operation of the whole organism. New words like potentiation are introduced rather than trying to explain these events in terms of the simple concepts introduced before. It left me wanting to stop reading the book.

I am thankful for the ways that the book introduced me to some classic work in behavioral neuroscience. The fact that these types of studies are still relevant and inspiring suggests that behavioral neuroscience still has a ways to go.