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Category Laboratory at Vanderbilt

supported by NSF, NEI, and Vanderbilt University

In the CatLab, we study visual cognition, including visual categorization, visual memory, and visual decision making. We study how objects are perceived and represented by the visual system, how visual knowledge is represented and learned, and how visual decisions are made. We approach these questions using a combination of behavioral experiments, cognitive neuroscience techniques, and computational and neural modeling. One line of work, funded by the National Science Foundation, investigates the temporal dynamics of visual object categorization and perceptual expertise for objects and faces. Another line of work, funded by the National Eye Institute, uses computational modeling of visual decision making to predict behavioral dynamics and neural dynamics.


Braden Purcell wins Jum Nunnally Dissertation Award

Posted on Apr 22, 2014

Congratulations to Braden Purcell for winning the 2014 Jum Nunnally Dissertation Award! This makes the third CatLab PhD student to win this prestigious award, along with Mike Mack in 2011 and Jenn Richler in 2010.

The Jum Nunnally Dissertation Award recognizes a recent outstanding doctoral dissertation in the Department of Psychology. The recipient receives a certificate and a $500 award. Jum Nunnally came to Vanderbilt in 1960. In 1961, he became the second chair of the department. He served as chair from 1961-1964 and again from 1967-1970. Under Jum’s leadership, the department grew substantially in stature, including significant increases in both the number and quality of the faculty. A memorial fund to support student awards was established in 1982 by his friends and family. Proceeds from this fund were used to establish the Jum Nunnally Dissertation Award in 2010.

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Two new postdocs join the CatLab

Posted on Apr 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.

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Paper to appear in PNAS

Posted on Jan 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? 

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Three new contributions to edited volumes

Posted on Jan 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]

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New work from the CatLab

Posted on Oct 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.

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New NSF Grant

Posted on Jun 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.

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Congratulations to Alan Wong

Posted on May 22, 2013

Congrats to former CatLab graduate student Alan Wong,

who just earned tenure at the Chinese University of Hong Kong. Well deserved!

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Braden Purcell wins the Pat Burns Memorial Graduate Student Research Award

Posted on Apr 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.

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Jonathan Folstein accepts faculty position at Florida State University

Posted on Apr 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!

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Recent papers

Posted on Jan 9, 2013

Ross, D.A., Deroche, M., & Palmeri, T.J. (accepted, pending final revisions). Not just the norm: Exemplar-based models also predict face aftereffects. Psychonomic Bulletin & Review.

Richler, J.J., Palmeri, T.J., & Gauthier, I. (in press). Meanings, mechanisms, and measures of holistic processing. Frontiers in Perception Science.

Richler, J.J., Palmeri, T.J., & Gauthier, I. (in press). How does using object names influence visual recognition memory? Journal of Memory and Language.

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Braden Purcell accepted to CSHL summer course

Posted on Apr 25, 2012

Braden Purcell has been accepted to the Cold Spring Harbor Laboratory summer course in Computational Neuroscience: Vision. This is a highly competitive program. Congratulations to Braden on this outstanding accomplishment.

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New faces joining the lab

Posted on Apr 5, 2012

Jianhong Chen is joining the lab this fall as a new graduate student in Psychological Sciences. Jianhong is getting her undergraduate degree from Peking University, one of the top three universities in China, where she worked with professor Fang Fang. Her research at PKU focused on adaptation, perceptual learning and EEG. For her graduate study, she is interested in perceptual expertise.

We also have two undergraduates working in the laboratory this summer on research fellowships. Billy Bunce will work with Jenn Richler and Mike Mack on a project modeling perceptual expertise. Akash Umakantha will work with Braden Purcell on neural models of perceptual decision making.

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