Although physiological psychology was developed strictly at the end of the 19th century From a text by Wilhelm Wundt titled Principles of Physiological Psychology, this field of study has its roots in the ancient Greeks, who were already seeking to elucidate what makes us so unique.
Although philosophers such as Aristotle believed that the brain served only to cool the blood, thus believing that the spirit resided in the heart, figures such as Hippocrates and Galen offered a clearer insight into the importance of brain on behavior.
Galen, a Greek physician (129 – 200 AD) considered the brain to be such an important organ that he even dissected cows, sheep, pigs, cats and dogs just to study it.
Physiological psychology after the scientific revolution
Closer to chronology, in the 17th and 18th centuries, intellectual positions related to physics and mathematics have maintained a central focus in the study of behavior. A young René Descartes, fascinated by the hidden mechanisms that moved the statues of the royal gardens to the west of Paris, traced his theory of the functioning of the body around these technological devices.
In his mind, the pressurized water that moved the moving statues was replaced by cerebrospinal fluid, the cylinders by the muscles, and the valve by the pineal gland. This would lead more men of his time to postulate new models around the functioning of the human body.
Italian physiologist Luigi Galvani he dealt a blow to the way in which the system proposed by Descartes had been understood, Discovering that stimulation of a frog’s nerve caused the muscle to which it was attached to contract.
He observed that the brain does not inflate the muscles by sending pressurized fluid through the nerves.; the functioning of the nervous system was not so simple and mechanical. It was a vital contribution to the state of knowledge on the physiology of behavior.
Johannes Müller was another key figure in the birth of physiological psychology; his experimental work by removing and isolating animal organs on which he performed a thorough analysis of their responses by exposing them to various chemicals would come to explain that nerves are not only motors but also parts of a sensor system.
His greatest contribution was precisely his doctrine of specific nervous energies: the quality of sensation does not depend on the stimulus affecting the senses but on the type of nerve fiber involved in perception.
An example of this is that the electrical stimuli applied to the optic nerves cause only light sensations.
Pierre Florens and Paul Broca
Müller’s way was also shared by Pierre Flourens and Paul Broca, Those who have experimented directly on the organ through different techniques.
Flourens, a 19th-century French physiologist believed to be the founder of experimental brain science, examined the behavior of various animals after removing various parts of the brain and conclusively demonstrated that those removed parts of the organ were responsible for the affected function; in this way, an animal with the cerebellum removed will have motor coordination problems.
Years later, Paul Broca used principles similar to those of Flourens, But with specific patients, those who have speech problems. So, he found in postmortem studies that most of his patients (except one) had damage to the left third frontal gyrus.
Broca reported 25 cases with these alterations that affected the left hemisphere. Broca’s successes were a big boost because other characters like Wernicke will study the neuroanatomical bases related to language, And contributions related to the study of behavior have been maintained. Thanks to these contributions, among others, we know the logic behind aphasias.
Physiological psychology today
Currently, physiological psychologists are based on experimentation and use both generalization and reduction to explain behavior.
Physiological psychology it has a multidisciplinary character and is reinforced by sources such as medicine, biology, chemistry, etc.. Finally, it is also worth mentioning contributions such as those of Ramon i Cajal, Francisco Varela, Mark Rosenzweig, Arnold Leiman, among others. Together, they created the fundamental foundations for the development of this science.
- Rosenzweig, M & Leiman, A. (1992) Physiological Psychology. Spain: Mc Graw Hill.
- Sagan, Carl. 1986. Broca’s brain: reflections on the novel of science. New York: Ballantine Books.
- Kandel, ER; Schwartz, JH; Jessell, TM (2001). Principles of neuroscience. Madrid: McGraw Hill.
- Carlson, Neil. (2006). Behavioral physiology, Madrid, Pearson Education.