Psychology Chapter: Psychophysics and Emergence of Psychology

Study Notes

Psychophysics pioneered the quantification of certain mental processes and demonstrated a lawful relationship between physical stimuli and psychological impressions.
Key concepts: threshold, 'just noticeable difference' (jnd), Weber's Law, and Fechner's method.

Studied the sense of touch and found that sensitivity varies widely depending on the part of the body stimulated.
Formulated Weber's Law to describe the relationship between physical and psychological differences.
Found that the jnd is a function of the amount of existing stimulation.

Developed new methodologies in psychophysics, including the method of limits, the method of average error, and the method of constant stimuli.
Fechner's method had wide applicability and became a standard part of training programs for experimental psychologists.

Rudolph Hermann Lotze: influenced by Weber and Fechner, considered the father of experimental psychology.
Hermann Ludwig Ferdinand von Helmholtz: pioneered work in the perception of space and depth, and developed the tri-chromatic theory of color vision.

Wilhelm Maximilian Wundt established the first formal laboratory of psychology at the University of Leipzig in 1879.
Wundt's laboratory was the key to launching a new discipline that was to be international in scope.
Wundt's thought emphasized the unity and interdependence of mental and physical processes.
Voluntarism: Wundt's system of thought emphasized psychological causality, and the importance of being able to replicate findings.

Studied various psychological phenomena, including sensation, perception, and the abilities to distinguish colors and tones.
Used rigorous approaches to modest problems in physiological psychology, sensation, and perception.
Developed several apparatus, including the beat-making apparatus, the eye motion demonstrator, the perimeter, the sound interrupter, and the tachistoscope.### Psychology's Two Tasks
Psychology has two tasks: to discover the elements of consciousness and to study the connections between these elements.

Wundt believed in the existence of mental elements or pure sensations, such as the sensation of the beat of a metronome.
He recognized simple sensations as psychological elements.
Wundt defined sensation as an element of consciousness, and perception as combinations of outward sense impressions.
He believed that compound or combinations of elements may be passive (associations) or active (apperceptions).
Wundt's tridimensional theory of feeling involves pleasure and pain, strain and relaxation, and excitation and quiescence.

Wundt defined sensation as an element of consciousness and perception as combinations of outward sense impressions.
An idea generally refers to combinations that may come from memory, previous associations, etc.

Wundt believed that compound or combinations of elements may be passive (associations) or active (apperceptions).

Wundt is considered the founder of psychology because he wedded physiology and philosophy, bringing empirical methods to philosophical questions.
His principle of creative synthesis states that higher mental operations create new combinations that are more than the sum of their parts.

Emil Kraepelin learned experimental methodology from Wundt and applied it to early scientific studies of mental disorder.
Kraepelin advanced a theory of schizophrenia derived from Wundtian psychology.
He also studied the psychological effects of alcohol and morphine, establishing himself as a pioneer in psychopharmacology.
Kraepelin's work on dementia led to the study of Alzheimer's disease.
He envisioned a larger role for psychiatrists in the courtroom and believed the root of psychopathology to be largely organic.

Lightner Witmer founded clinical psychology and worked on topics such as perception of pain and special learning difficulties in children.
He opened the world's first clinic headed by a psychologist, which handled mainly learning disorders and problems of mentally handicapped children.

Wundt's students, including Emil Kraepelin and Lightner Witmer, made significant contributions to psychology, psychiatry, and psychopharmacology.
Their work built upon Wundt's principles and legacy, shaping the development of psychology and related fields.