Freud called this “the law of association by simultaneity” and he was one of the first people to put this understanding in scientific terms. In the 1880s, however, the technology had not yet developed to prove Freud was correct.
It may surprise some people to learn that Freud’s theories about this were not purely speculative, like some of his psychoanalytic theories. Rather, they were based on his early work as a brain scientists. Many people do not realize that prior to pursuing a career as a psychoanalyst, Freud worked in the laboratory as a neuroscience researcher.
In Joseph LeDoux fascinating book Synaptic Self: How our Brains Become Who We Are, LeDoux tells how directly after the completion of his medical training in Vienna, Freud took a position as a neuroscience researcher, studying the brains of fish and catfish. Through Freud’s studies of animal brains, he gradually developed a theory that sounded preposterous at the time, but which has recently been proved entirely correct.
More about that in the next post.