Richard Shiffrin

In the 1980s, Shiffrin's formal theory of memory took a great leap forward with the Search of Associative Memory (SAM) model. This model quantified the nature of retrieval from long-term memory and characterized recall as a memory search with cycles of sampling and recovery. In 1984, another quantum step forward occurred, when the theory was extended to recognition memory, in which a decision is based on summed activation of related memory traces. It was a major accomplishment that the same retrieval activations that had been used in the recall model could be carried forward and used to predict a wide range of recognition phenomena. Another major step, In 1990, Shiffrin published two articles on the list-length effect which clearly established that experience leads to the differentiation, rather than the mere strengthening, of the representations of items in memory. In 1997 Shiffrin extended the SAM model with the Retrieving Effectively From Memory (REM) model.

Shiffrin proposed a mathematical model of memory with Richard C. Atkinson in 1968 while at Stanford University. This laid out components of short and long term memory and processes that control the operations of memory. The Atkinson-Shiffrin memory model showed the importance and possibility of modeling the control processes of cognition, and remains one of the most highly cited in the entire field of psychology.

Shiffrin graduated with a Ph.D. in Mathematical Psychology from Stanford in 1968, and joined Indiana University as faculty that same year, where he remains today as a distinguished Professor and Luther Dana Waterman Professor of Psychological and Brain Sciences in the College of Arts and Sciences. Shiffrin also directs the department's Memory and Perception Laboratory.

Richard Shiffrin (born March 13, 1942) is an American psychologist, professor of cognitive science in the Department of Psychological and Brain Sciences at Indiana University, Bloomington. Shiffrin has contributed a number of theories of attention and memory to the field of psychology. He co-authored the Atkinson–Shiffrin model of memory in 1968 with Richard Atkinson, who was his academic adviser at the time. In 1977, he published a theory of attention with Walter Schneider. With Jeroen G.W. Raaijmakers in 1980, Shiffrin published the Search of Associative Memory (SAM) model, which has served as the standard model of recall for cognitive psychologists well into the 2000s. He extended the SAM model with the Retrieving Effectively From Memory (REM) model in 1997 with Mark Steyvers.