Ernst Heinrich Weber

Ernst Heinrich Weber
Ernst Heinrich Weber
Born	24 June 1795 Wittenberg, Saxony, Holy Roman Empire
Died	26 January 1878 (1878-01-27) (aged 82) Leipzig, Saxony
Nationality	German
Fields	Physician
Institutions	Leipzig University
Alma mater	Leipzig University (MD, 1815)
Doctoral advisor	Johann Christian Rosenmüller
Other academic advisors	Ernst Chladni Ludwig Wilhelm Gilbert Johann Christian August Clarus
Notable students	Hermann Lotze
Known for	Experimental psychology

Ernst Heinrich Weber (24 June 1795 – 26 January 1878) was a German physician who is considered one of the founders of experimental psychology. Weber (1795-1878) was an influential and important figure in the areas of physiology and psychology during his lifetime and beyond. His studies on sensation and touch, along with his emphasis on good experimental techniques gave way to new directions and areas of study for future psychologists, physiologists, and anatomists.

Ernst Weber was born into an academic background, with his father serving as a professor at the University of Wittenberg. Weber became a doctor, specializing in anatomy and physiology. Two of his younger brothers, Wilhelm and Eduard, were also influential in academia, both as scientists with one specializing in physics and the other in anatomy. Ernst became a lecturer and a professor at the University of Leipzig and stayed there until his retirement.

Ernst Heinrich Weber was born on 24 June 1795 in Wittenberg, Saxony, Holy Roman Empire. He was son to Michael Weber, a professor of theology at the University of Wittenberg. At a young age, Weber became interested in physics and the sciences after being heavily influenced by Ernst Chladni, a physicist often referred to as the “father of acoustics”. Weber completed secondary school at Meissen and began studying medicine at the University of Wittenberg in 1811. He went on to receive his MD in 1815 from the University of Leipzig. The fighting and the aftermath of the Napoleonic wars forced Weber to relocate from Wittenberg. He became an assistant in J.C. Clarus’ medical clinic in Leipzig in 1817 and then a professor in comparative anatomy in 1818 at the University of Leipzig. He became chair of human anatomy at the university in 1821. Ernst Weber’s first direct contribution to psychology came in 1834 when trying to describe the sensation of touch.

Just-Noticeable Difference: Weber describes just-noticeable difference as the following, “in observing the disparity between things that are compared, we perceive not the difference between the things, but the ratio of this difference to the magnitude of things compared.” In other words, we are able to distinguish the relative difference, not the absolute difference between items. Or, we can discern between some constant ratio, not some constant difference. Weber’s first work with JND had to do with differences in weight, in that JND is the "minimum amount of difference between two weights necessary to tell them apart". For this, Weber found that the finest discrimination between weights was when they differed by 8-10%. For example, if you were holding a 100g block, the second block would need to weigh at least 103g in order to notice a difference. Weber also suspected that a constant fraction applied for all senses, but is different for each sense. When comparing the differences in line length, there must be at least 0.01 difference in order to distinguish the two. When comparing music pitch, there must be at least 0.006 vibrations per second difference. So for every sense, some increase in measurement is needed in order to tell a difference.