Experimental psychology

Experimental psychology refers to work done by those who apply experimental methods to psychological study and the processes that underlie it. Experimental psychologists employ human participants and animal subjects to study a great many topics, including (among others) sensation & perception, memory, cognition, learning, motivation, emotion; developmental processes, social psychology, and the neural substrates of all of these. Experimental psychology refers to work done by those who apply experimental methods to psychological study and the processes that underlie it. Experimental psychologists employ human participants and animal subjects to study a great many topics, including (among others) sensation & perception, memory, cognition, learning, motivation, emotion; developmental processes, social psychology, and the neural substrates of all of these. Experimental psychology emerged as a modern academic discipline in the 19th century when Wilhelm Wundt introduced a mathematical and experimental approach to the field. Wundt founded the first psychology laboratory in Leipzig, Germany. Other experimental psychologists, including Hermann Ebbinghaus and Edward Titchener, included introspection among their experimental methods. Charles Bell was a British physiologist, whose main contribution was research involving the nervous system. He wrote a pamphlet summarizing his research on rabbits. His research concluded that sensory nerves enter at the posterior (dorsal) roots of the spinal cord and motor nerves emerge from the anterior (ventral) roots of the spinal cord. Eleven years later, a French physiologist Francois Magendie published the same findings without being aware of Bell's research. Due to Bell not publishing his research, the discovery was called the Bell-Magendie law. Bell's discovery disproved the belief that nerves transmitted either vibrations or spirits. Weber was a German physician who is credited with being one of the founders of experimental psychology. His main interests were the sense of touch and kinesthesis. His most memorable contribution is the suggestion that judgments of sensory differences are relative and not absolute. This relativity is expressed in 'Weber's Law,' which suggests that the just-noticeable difference, or jnd is a constant proportion of the ongoing stimulus level. Weber's Law is stated as an equation: where I {displaystyle I!} is the original intensity of stimulation, Δ I {displaystyle Delta I!} is the addition to it required for the difference to be perceived (the jnd), and k is a constant. Thus, for k to remain constant, Δ I {displaystyle Delta I!} must rise as I increases. Weber's law is considered the first quantitative law in the history of psychology. Fechner published in 1860 what is considered to be the first work of experimental psychology, 'Elemente der Psychophysik.' Some historians date the beginning of experimental psychology from the publication of 'Elemente.' Weber was not a psychologist, and it was Fechner who realized the importance of Weber's research to psychology. Fechner was profoundly interested in establishing a scientific study of the mind-body relationship, which became known as psychophysics. Much of Fechner's research focused on the measurement of psychophysical thresholds and just-noticeable differences, and he invented the psychophysical method of limits, the method of constant stimuli, and the method of adjustment, which are still in use. Oswald Külpe is the main founder of the Würzburg School in Germany. He was a pupil of Wilhelm Wundt for about twelve years. Unlike Wundt, Külpe believed experiments were possible to test higher mental processes. In 1883 he wrote Grundriss der Psychologie, which had strictly scientific facts and no mention of thought. The lack of thought in his book is odd because the Würzburg School put a lot of emphasis on mental set and imageless thought. The work of the Würzburg School was a milestone in the development of experimental psychology. The School was founded by a group of psychologists led by Oswald Külpe, and it provided an alternative to the structuralism of Edward Titchener and Wilhelm Wundt. Those in the School focused mainly on mental operations such as mental set (Einstellung) and imageless thought. Mental set affects perception and problem solving without the awareness of the individual; it can be triggered by instructions or by experience. Similarly, according to Külpe, imageless thought consists of pure mental acts that do not involve mental images. An example of mental set was provided by William Bryan, an American student working in Külpe's laboratory. Bryan presented subjects with cards that had nonsense syllables written on them in various colors. The subjects were told to attend to the syllables, and in consequence they did not remember the colors of the nonsense syllables. Such results made people question the validity of introspection as a research tool, and led to a decline of voluntarism and structuralism. The work of the Würzburg School later influenced many Gestalt psychologists, including Max Wertheimer. Experimental psychology was introduced into the United States by George Trumbull Ladd, who founded Yale University's psychological laboratory in 1879. In 1887, Ladd published Elements of Physiological Psychology, the first American textbook that extensively discussed experimental psychology. Between Ladd's founding of the Yale Laboratory and his textbook, the center of experimental psychology in the US shifted to Johns Hopkins University, where George Hall and Charles Sanders Peirce were extending and qualifying Wundt's work.