Center for Perceptual Systems

Leslie B Cohen

Professor EmeritusPh.D., University of California, Los Angeles

Leslie B Cohen


  • Phone: (512) 471-0189
  • Office: SEA 1.206 (B, BA)
  • Campus Mail Code: A8000


Cohen's primary research interests are in perception, memory, and cognition of infants. In general his research has been examining how infants process and use visual and auditory information in their environment. Most studies involve some variation of a habituation paradigm which Dr. Cohen revised for use in infant research. In this paradigm infants' looking times are recorded while they are repeatedly exposed either to a single stimulus or to multiple stimuli and are then tested with familiar versus novel stimuli. Most of the stimuli are actual events generated through sophisticated computer animation techniques or videotaped and then presented to the infants. Some of the specific research questions being investigated by Dr. Cohen are 1. How do infants come to understand concepts and categories? 2. What principles govern infants' early language? 3. How do infants process causal relations and other visual events? 4. At what age do infants perceive both the form and function of objects with which they interact?


Cashon C. & Cohen L.(2004) Beyond U-Shaped Development in Infants. Cognition and Development, 5, 59-80.

Cohen.L., Atkinson, D. & Chaput, H. (2004) A new program for obtaining and organizing data in infant perception and cognition studies, (Version 1.0).. University of Texas University of Texas

Cohen.L., Casasola, M. & Chiarello, E. (2003) Six-month-old infants' categorization of containment spatial relations. Child Development

Cashon C. & Cohen L. (2003) The construction, deconstruction, and reconstruction of infant face perception.. Nova Science.

Cohen.L. (2003) Unresolved issues in infant categorization. Oxford University Press. (pp 193-209).

Cohen.L. & Cashon, C. (2003) Infant perception and cognition. In R. Lerner, A. Easterbrooks, and J. Mistry (Eds.), Comprehensive handbook of psychology.Volume 6, Developmental Psychology. II. Infancy.(pp 65-89)   New York: Wiley and Sons.

Casasola M. & Cohen L. (2002) Infant categorization of containment, support and tight-fit spatial relationships. Developmental Science, 5, 247-264.

Cohen.L. & Chaput, H. (2002) Connectionist models of infant perceptual and cognitive development. Developmental Science, 5, 173-175.

Cohen.L. & Marks, K. (2002) How infants process addition and subtraction events. Developmental Science, 5, 186-201.

Cohen.L. & Chaput, H. (2001) A model of infant causal perception and its development. Proceedings of the Twenth-Third Annual Conference of the Cognitive Science Society,(pp182-187). Mahway: Lawrence Erlbaum Associates.

Career Overview

Dr. Cohen received his Ph.D. from UCLA in 1966. He then completed a post-doctoral fellowship at the University of Minnesota and in 1967 became an assistant professor in psychology at the University of Illinois. In 1979, he was recruited by The University of Texas and moved to Austin as a full professor in 1980. He continued in the Department of Psychology until the end of his phased retirement in 2010. During this period in 2001, he became an affiliated faculty member in both the Center for Perceptual Systems and the Artificial Intelligence Laboratory in the Department of Computer Science at The University of Texas. He also was a visiting professor at Beijing Normal University in the summer of 1985, in the Department of Psychology at the University of British Columbia in 1991, and in the Department of Cognitive Science at the University of California at San Diego in 1998.

Dr. Cohen’s primary line of research has been an investigation of infant perceptual, cognitive, and language development. This research interest actually began in the 1960s, when he was one of the top two or three researchers defining the field. The area really began in 1964 with Dr. Robert Fantz’ discovery that infants usually prefer to look at something novel than at something familiar. Dr. Cohen used that preference to develop a technique called habituation in which infants are repeatedly presented with the same stimulus until they get bored with it and decrease their looking at it. At that point, a novel stimulus is introduced and researchers see if infants increase their looking once again. If they do, one can conclude that the infants notice something differs between the old repeated item and the new item. Literally thousands of experiments have used this technique to examine everything from basic visual and auditory perception, to complex concept formation, categorization, music perception, and several aspects of language acquisition.

It soon became clear that in order to replicate and verify habituation findings from several different labs, the technique needed to be standardized. Dr. Cohen developed a simple computer program called “Habit” which included a variety of options to do just that, without hampering experimental variations and innovations. Dr. Cohen provided this program at no cost to infant research laboratories around the world, and “Habit” has now been used by more than 150 such laboratories. “Habit” has been successfully employed in hundreds, more likely thousands, of studies from his laboratory and others to investigate basic visual perception, auditory perception, categorization, concept formation, number perception, causal reasoning, facial perception, music perception, speech and sign language, and many other topics in both normal and handicapped infants. Dr. Cohen and his collaborators have produced over 250 articles, papers, book chapters, and four edited volumes on various aspects of infant perception and cognition.

Of course, an appropriate laboratory was needed to investigate these topics. Dr. Cohen and his colleagues designed one of the foremost infant research facilities here at The University of Texas. It included controlled testing rooms; a computerized database of infant names and addresses, shared by several investigators; parking spaces for parents next to the building; and a specialized ramp for strollers so mother and infant could enter the facility easily. It also included a waiting room, library, and office space for graduate and undergraduate assistants. In fact this laboratory has served as a model for other infant testing facilities around the world and several visiting investigators have attempted to emulate some or all of it.

Dr. Cohen also trained numerous graduate students who investigated some aspect of infant perceptual and/or cognitive development. Most of these students later became professors themselves at prestigious universities, including the University of Illinois, University of Virginia, Carnegie Mellon University, Indiana State University, University of California at Davis, Cornell University, Purdue University, University of Pittsburgh, University of Western Kentucky, University of Michigan, University of Iowa, and University of Louisville.

He also has collaborated with investigators from other laboratories, including the artificial intelligence group in computer science at The University of Texas. They are attempting to get robots to adapt and learn about their environment and are using learning principles Dr. Cohen discovered that human infants use. Currently, Dr. Cohen is collaborating with a group on a project at The University of Texas Health Science Center in Houston. They are attempting to discover specific ways infants with disabilities (spina bifida or cerebral palsy) differ cognitively from infants without those disabilities.

Another active collaboration has been with Professor Kim Plunkett at Oxford University on the effect of labels on infant categorization. This groundbreaking work combined three things: infant categorization, infant labeling, and connectionist modeling to predict whether infants would use the labels to form one or two separate categories of animals.

The artificial intelligence and modeling work has been important for two separate reasons. First, it has allowed researchers to make quantitative predictions about infant cognitive ability, predictions that have been confirmed; and second, it makes an important contribution to the longstanding nature-nurture debate. Some believe many cognitive and mathematical concepts are built-in. Given the enormous number of such concepts, this position clearly is untenable. On the other hand, if only a small number of connectionist learning principles need be built in, infants should be able to master a great many cognitive and linguistic concepts over time.

For many years Dr. Cohen has been a Fellow in the Association for Psychological Science and in the American Psychological Association. He spent six years on the National Institute for Child Health and Human Development Study Section evaluating developmental grants and chaired that Study Section for two years. He also chaired the International Society for Infant Studies, one of the most prestigious infant research societies, and was founding editor of the prestigious research journal, “Infancy” which is now in its 15th year of publication.