Larry L. Jacoby (March 11, 1944–March 15, 2024) was an American cognitive psychologist specializing in research on human memory.

[1] In his profile in the APS journal, Observer, Jacoby is described as "one of the world's foremost researchers on memory".

Jacoby is on the Thomson Reuters list of highly cited researchers (an explicit definition of scholarly influence).

[3] From 1994 to 1995, Jacoby held an endowed position, the David Wechsler Chair at the University of Texas at Austin.

He was on the faculty of McMaster University (Hamilton, Ontario, Canada) for many years, where he collaborated with colleagues Lee Brooks, Ian Begg, Betty Ann Levy, and Bruce Milliken and long-time research assistant Ann Hollingshead, and interacted with colleagues at University of Toronto-Erindale including Fergus Craik, Gordon Logan, Morris Moscovitch, and Endel Tulving.

Later, he held the David Wechsler Chair in the Department of Psychology at the University of Texas at Austin.

Jacoby published steadily throughout the 1970s, producing a number of works that have attracted multiple citations, such as a 1978 article on how, when a problem is repeated, a person may solve it by remembering the prior solution.

In the 1980s, a major theme in Jacoby's work was that the feeling of remembering does not inhere in the use of memory traces.

As he noted, one can use memory records of specific past episodes without having a subjective feeling of remembering (as in involuntary plagiarism) and one can have a subjective feeling of remembering without there being any directly corresponding prior episode and hence no directly corresponding memory trace (as in false-memory phenomena).

Jacoby argued that the feeling of remembering arises when a person infers (usually very quickly and without conscious reflection) that current thoughts and images are based on memories of a prior episode – that is, when people attribute current mental events to the past.

For a beautifully written and compelling synthesis of Jacoby's work on this perspective, see his 1989 chapter with Colleen Kelley and Jane Dywan in a book in honour of Endel Tulving coedited by Roediger and Craik.

That is, both unconscious and/or conscious uses of memory for the study-list encounter with “Sebastian Weisdorf” could influence subjects toward endorsing that name as famous.

One way to do this is simply to correctly inform subjects (in the case of this fame procedure) that all of the names on the study list were non-famous.

Jacoby, Woloshyn, and Kelley (1989) found that when subjects had studied the list with full attention, these opposition instructions led them to be less likely to endorse studied names as famous than to endorse non-studied names as famous.

Presumably dividing attention at study impaired subject ability to consciously recollect which names had been on the list, but left intact more automatic, unconscious influences of familiarity.

The PDP is a method for obtaining separate quantitative estimates of the concurrent contributions of two different sources of influence on task performance (e.g., conscious vs. unconscious perception; habit vs. intention; familiarity vs. recollection).

Using simple algebraic equations and certain assumptions, Jacoby derived estimates of the two underlying categories of influence.

Jacoby and former student Andy Yonelinas provided an update on the status of the PDP in a 2012 article.

Jacoby's recent work has explored various aspects of the notion of cognitive control—ways the mind/brain constrains its own operation so as to enhance the production of some kinds of mental contents relative to others.

One key notion is that control can often be exercised “at the front end” and thereby modulate the thoughts and images that come to mind (whereas most prior theorizing about control emphasized output monitoring and filtering) (e.g., Halamish, Goldsmith, & Jacoby, 2012; Jacoby, Shimizu, Daniels, & Rhodes, 2005).

[22] Roddy Roediger, Steve Lindsay, Colleen Kelley, and Andy Yonelinas organized a Festschrift in Larry's honour.

The event was held at Washington University over two days in the spring of 2013 and featured 24 speakers and an audience of approximately 100 people.

A book featuring 22 chapters based on talks given at this Festschrift was published in 2014 (publication year 2015) by Psychology Press.