Welcome to the CatLab, the web site for Tom Palmeri’s laboratory at Vanderbilt University.

Our laboratory studies how people visually categorize, identify, and recognize objects. We examine how objects are processed and represented by the visual system, how visual knowledge about objects is represented and learned, and how perceptual decisions about objects are made. We are particularly interested in the temporal dynamics of visual object recognition. That includes the short-term dynamics of an individual decision about an object’s category or identity and the long-term dynamics of how those decisions change with learning and perceptual expertise. We approaches these questions using a combination of behavioral experiments, cognitive neuroscience techniques, and computational and neural modeling.

Open Positions in the CatLab:
Postdoctoral Fellowship on Object Categorization and Perceptual Expertise
Graduate Student Fellowships and Research Assistantships

Our research is and has been generously funded by grants from the National Science Foundation, the National Institutes of Health, the James S. McDonnell Foundation, as well as Vanderbilt Discovery, VIO, and IDEAS grants.

ORCID ID: 0000-0001-7617-9797

Recent Lab News

  • Two new postdocs join the CatLab

    April 1, 2014

    Brent Miller joins to lab as a postdoctoral fellow this month with a background in computer engineering and psychology. He comes from the University of California, Irvine, where he received his PhD in 2014 with Mark Steyvers. Brent is broadly interested in how the mechanisms of information storage, retrieval, and encoding affect judgment and decision making. Previously, he used computational modeling to show how certain decision behavior necessarily arises from probabilistic information representation in the brain. As a postdoctoral fellow at Vanderbilt, he will work on developing and testing computational models of behavior and neurophysiology in our collaboration with Jeff Schall and Gordon Logan.

    Jeff Annis will receive his PhD from the University of South Florida this summer, where he has been studying the relationship between memory and perception via sequential dependencies with Ken Malmberg. Jeff is interested in the mechanisms and representations involved in memory and categorization. He will join the lab as postdoctoral fellow this summer to use computational models and empirical investigations to understand the dynamics of perceptual expertise.

  • Recent PNAS paper highlighted by Vanderbilt News

    February 13, 2014

    Research News@Vanderbilt recently did a story about our PNAS paper, “Response times from ensembles of accumulators”: http://news.vanderbilt.edu/2014/02/number-of-neurons/

  • Paper to appear in PNAS

    January 8, 2014

    Zandbelt, B.B., Purcell, B.A., Palmeri, T.J., Logan, G.D., Schall, J.D. (2014). Response times from ensembles of accumulators. Proceedings of the National Academy of Sciences. [PDF]

    Decision making is explained by psychologists through stochastic accumulator models and by neurophysiologists through the activity of neurons believed to instantiate these models. This paper investigated an overlooked scaling problem: How does a response time (RT) that can be explained by a single model accumulator arise from numerous, redundant accumulator neurons, each of which individually appears to explain the variability of RT? 

  • Three new contributions to edited volumes

    January 8, 2014

    Three new papers. Two in the Oxford Handbook of Computational and Mathematical Psychology and one in An Introduction to Model-Based Cognitive Neuroscience.

    Palmeri, T.J., Schall, J.D. & Logan, G.D. (in press). Neurocognitive modeling of perceptual decision making. To appear in J.R. Busemeyer, J. Townsend, Z.J. Wang, & A. Eidels (Eds.), Oxford Handbook of Computational and Mathematical Psychology, Oxford University Press. [PDF]

    Nosofsky, R.M., & Palmeri, T.J. (in press). Exemplar-based random walk model. To appear in J.R. Busemeyer, J. Townsend, Z.J. Wang, & A. Eidels (Eds.), Oxford Handbook of Computational and Mathematical Psychology, Oxford University Press. [PDF]

    Logan, G.D., Schall, J.D., & Palmeri, T.J. (in press). Inhibitory control in mind and brain: The mathematics and neurophysiology of the underlying computation. To appear in B. Forstmann & E.J. Wagenmakers (Eds.), An Introduction to Model-Based Cognitive Neuroscience, Springer Neuroscience. [PDF]

  • New work from the CatLab

    October 24, 2013

    New Papers

    Palmeri, T.J. (in press). An exemplar of model-based cognitive neuroscience. Trends in Cognitive Science. [PDF]

    Richler, J.J., & Palmeri, T.J. (in press). Visual category learning. To appear in Wiley Interdisciplinary Reviews in Cognitive Science. [PDF]

    Upcoming Conference Presentations

    Palmeri, T.J. (2013). Neurocognitive modeling of perceptual decision making. To be presented at Interfacing Models with Brain Signals to Investigate Cognition, UC Irvine, CA.

    Richler, J.J., Palmeri, T.J., & Gauthier, I. (2013). The effects of varying configuration in the composite task support an attentional account of holistic processing. To be presented at Object Perception and Memory (OPAM), Toronto, Ontario, Canada.

    Middlebrooks, P.G., Schall, J.D., Palmeri, T.J., & Logan, G.D. (2013). Modeling response time and accuracy of perceptual choice during a stop-signal task. To be presented at the Society for Neuroscience meeting, San Diego, CA.

    Zandbelt, B.B., Schall, J.D., Palmeri, T.J., & Logan, G.D. (2013). Modeling response time and accuracy during a stop-signal task: Stimulus-response choice. To be presented at the Society for Neuroscience meeting, San Diego, CA.

  • New NSF Grant

    June 3, 2013

    The National Science Foundation has officially awarded our lab a new grant entitled “Perceptual Categorization in Real-World Expertise”. Now the work begins.

  • Congratulations to Alan Wong

    May 22, 2013

    Congrats to former CatLab graduate student Alan Wong, who just earned tenure at the Chinese University of Hong Kong. Well deserved!

  • Braden Purcell wins the Pat Burns Memorial Graduate Student Research Award

    April 24, 2013

    Congratulations to Braden Purcell for winning the The Pat Burns Memorial Graduate Student Research Award.

    Pat Burns touched generations of doctoral students during her nearly four decades of service to Vanderbilt University. In memory of her tireless efforts to help guide our students through all phases of their graduate education, the Department of Psychology establishes a Graduate Student Research Award to recognize outstanding achievement in research by our most outstanding graduate students. The recipient receives a plaque and a $500 award.

    Along with Michael Mack and Jennifer Richler, this makes the third CatLab member to win this prestigious award.

  • Jonathan Folstein accepts faculty position at Florida State University

    April 9, 2013

    Jonathan Folstein, a recent postdoctoral fellow in the CatLab and OPL, has accepted a faculty position in psychology at Florida State University. Congratulations Dr. Folstein!

  • Congratulations Dr. Purcell

    March 15, 2013

    On Friday March 15, 2013, Braden Purcell successfully defending his PhD thesis entitled Neural Mechanisms of Perceptual Decision Making. Dr. Purcell will soon begin a postdoctoral fellowship at NYU with Roozbeh Kiani and Xiao-Jing Wang.

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