Reflex theory, cautionary tale: misleading simplicity in early neuroscience

M Chirimuuta

doi:10.1007/s11229-021-03351-w

Abstract

This paper takes an integrated history and philosophy of science approach to the topic of "simplicity out of complexity". The reflex theory was a framework within early twentieth century psychology and neuroscience which aimed to decompose complex behaviours and neural responses into simple reflexes. It was controversial in its time, and did not live up to its own theoretical and empirical ambitions. Examination of this episode poses important questions about the limitations of simplifying strategies, and the relationship between simplification and the engineering approach to biology.

Highlights

Most recent philosophical work on simplifying strategies, such as abstraction, in science examines cases of prima facie successful, or at least useful science, and offers accounts of how it is that the science works as well as it does, given that its theoriesThis article belongs to the topical collection “Simplicity out of Complexity? Physics and the Aims of Science”, edited by Florian J
My topic is “reflexology,” the outmoded term for the branch of neurophysiology and psychology1 centred around the simplifying assumption that complex patterns of behaviour are concatenations of simple reflex responses, exemplified by the sensory-motor reflex arc discovered in the 1830’s
In his history of the reflex theory, the psychologist Franklin Fearing writes that, For those sciences which are primarily devoted to the study of the integrated responses of living organisms, the concept of reflex action has played, in the 19th and first twenty-five years of the 20th century, a dominating role, comparable, perhaps, to the influence of the Newtonian hypotheses in physics. (1930, p. 4)3

Summary

Introduction

Most recent philosophical work on simplifying strategies, such as abstraction, in science examines cases of prima facie successful, or at least useful science, and offers accounts of how it is that the science works as well as it does, given that its theories. Deliberate omission of detail (abstraction), or introduction of falsehood (idealisation), within a representation such as a mathematical model, the reflex theory employed the simplifying strategy of decomposition of a complex system (the nervous system) or phenomenon (behaviour of an animal) into putative elementary parts—the reflex arc or the reflex response. These reflexes were metaphorical “elements” or “atoms”—parts whose properties were posited to stay the same regardless of varying conditions around them, or observable changes in the animal’s pattern of movements. We will turn to criticisms of the reflex theory, and see that much of the scepticism is focussed on the assumption of the existence–outside of controlled laboratory conditions–of any of these simple and elementary reflexive responses

The criticisms of reflexology

Evaluation and arbitration

Lessons?