Section 3–6 Psychology

(Psychoanalysis / Physiology of sensation / Computing machines)

Feynman suggests that there are changes in brain cells if they are made out of atoms. In this section, the three interesting ideas discussed are psychoanalysis, physiology of sensation, and computing machines.

1. Psychoanalysis:

“… Psychoanalysis has not been checked carefully by experiment, and there is no way to find a list of the number of cases in which it works, the number of cases in which it does not work (Feynman et al., 1963, section 3.6 Psychology).”

According to Feynman, psychoanalysis is not really a science because it has not been checked carefully by experiment. That is, there is no way to specify a list of the number of cases that a psychological theory works and the number of cases that it does not work. Thus, he reasons that psychoanalysis is at best a medical process, but perhaps it is closer to witch-doctoring. However, there are an increasing number of physicists and physics teachers using psychological method or psychoanalysis in physics education research to improve physics students’ learning of physical concepts.

In one of his Messengers lectures, Feynman says that we are unable to determine the correct theory from two theories that are psychologically different. In his own words, “[s]uppose you have two theories, A and B, which look completely different psychologically, with different ideas in them and so on, but that all the consequences that are computed from each are exactly the same, and both agree with experiment. The two theories, although they sound different at the beginning, have all consequences the same, which is usually easy to prove mathematically by showing that the logic from A and B will always give corresponding consequences. Suppose we have two such theories, how are we going to decide which one is right? There is no way by science because they both agree with experiment to the same extent (Feynman, 1965, p. 168).”

Note: During the Manhattan project in Los Alamos, Feynman used a psychological method to open locks. In his autobiography Surely you’re Joking, Mr. Feynman!, he reveals that “when I thought of the safecracker books again: Next, try the psychology method. I said to myself, ‘Freddy de Hoffman is just the kind of guy to use a mathematical constant for a safe combination.’ I went back to the first filing cabinet and tried 27-18-28-- CLICK! It opened! (The mathematical constant second in importance to pi is the base of natural logarithms, e: 2.71828…) (Feynman, 1997, p. 148).”

2. Physiology of sensation:

“… The other branches of psychology, which involve things like the physiology of sensation—what happens in the eye, and what happens in the brain—are, if you wish, less interesting (Feynman et al., 1963, section 3.6 Psychology).”

Feynman mentions that the physiology of sensation (another branch of psychology) which involves things such as what happens in the eye, and what happens in the brain are less interesting, but a real progress has been made in studying them. More interesting is the central problem of the mind (or the nervous system) when an animal learns something: it can do something that is different from what it could do earlier, and there must be changes in brain cells. Curiously, Feynman opines that we do not know where to look, or what to look for, when something is memorized. However, there are studies of brains using functional magnetic resonance imaging to understand working memories and logical reasoning of human beings. We need not find fault with Feynman here because magnetic resonance imaging was accomplished in 1977.

Note: In Volume I, Chapter 36 of his lectures, Feynman discusses the sensation of color. Initially, he elaborates that physics and other sciences are very closely interrelated, such that the separation of science into different fields is merely a human convenience and it is an unnatural thing. In essence, nature is not interested in the separation of science, and a color is not simply about physics of the light, but it is also a sensation that is different in different circumstances. Historically, Helmholtz proposes that there are three different pigments in the eyes which receive light rays. These pigments have different absorption spectra, for example, one pigment may absorb red color light more strongly as compared to blue and green.

3. Computing machines:

“… There is an analog of this to computing machines and computing elements, in that they also have a lot of lines, and they have some kind of element, analogous, perhaps, to the synapse, or connection of one nerve to another (Feynman et al., 1963, section 3.6 Psychology).”

Feynman assumes the brain is similar to an enormous mass of interconnecting wires such that it cannot be analyzed in a straightforward manner. Alternatively, the brain is analogous to computing machines in that they also have a lot of lines (or wires) and they have some kind of element similar to the synapse, or connection of one nerve to another. However, there is a lack of time to further discuss the relationship between thinking and computing machines. To conclude, we even have a limited understanding of how dogs work and thus, it will be a long time before we can have a better understanding of human behavior that is more complex.

Note: in the fall of 1983, Feynman gave a course on the physics of computation that is listed in the Caltech record as “Potentialities and Limitations of Computing Machines.” In the subsequent years 1984/85 and 1985/86, the lectures on computation were taped and it was from those tapes and Feynman’s notebooks that the lectures were published. In the preface of Feynman lectures on computation, Feynman (1996) explains that “[c]omputer science also differs from physics in that it is not actually a science. It does not study natural objects (p. xiii).” In the first chapter, he adds that computers “can guide weapons to their targets. They can book you onto a plane between a guitar-strumming nun and a non-smoking physics professor (p. 1).”

Questions for discussion:

1. Why psychoanalysis is not a science?

2. In what way is our mind (or brain) different when something is memorized?

3. How is the brain analogous to computing machines or computer?

The moral of the lesson: when an animal learns something, it can do something that is different from before, and there must be changes in its brain cells because they are made of atoms.

References:

1. Feynman, R. P. (1965). The character of physical law. Cambridge: MIT Press.

2. Feynman, R. P. (1997). Surely You’re Joking, Mr. Feynman! : Adventures of a Curious Character. New York: Norton.

3. Feynman, R. P., Leighton, R. B., & Sands, M. (1963). The Feynman Lectures on Physics, Vol I: Mainly mechanics, radiation, and heat. Reading, MA: Addison-Wesley.

4. Feynman, R. P. (1996). Feynman lectures on computation. Reading, Massachusetts: Addison-Wesley.