CATLAB

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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.

News

Symposium on Model-based Cognitive Neuroscience at Psychonomics this Fall

Posted on Jul 18, 2016

Thomas Palmeri and Brandon Turner from The Ohio State University will be chairing a symposium on Model-based Cognitive Neuroscience at the 2016 Annual Meeting of the Psychonomics Society. After an Introduction to Model-based Cognitive Neuroscience, Thomas Palmeri will present Approaches to Model-Based Cognitive Neuroscience: Bridging Levels of Understanding of Perceptual Decision Making, Brandon Turner will present Joint Models of Neural and Behavioral Data, Birte Forstmann from the University of Amsterdam will present Decision Threshold Dynamics in the Human Subcortex Measured with Ultra-high Resolution Magnetic Resonance Imaging, John Anderson from Carnegie Mellon will present Combining Space and Time in the Mind, Michael Mack from the University of Toronto will present Tracking the Neural Dynamics of Conceptual Knowledge During Category Learning with Computational Model-based Neuroimaging, and Sean Polyn from Vanderbilt University will present The Neurocognitive Dynamics of Memory Search.

Full abstracts can be found on the Psychonomics Society web site:
http://www.psychonomic.org/2016-symposia

 

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Recent papers from the CatLab

Posted on Jul 6, 2016

Purcell, B.A., & Palmeri, T.J. (in press). Relating accumulator model parameters and neural dynamics. Journal of Mathematical Psychology.

Turner, B.M., Forstmann, B.U., Love, B., Palmeri, T.J., & Van Maanen, L. (in press). Approaches to analysis in model-based cognitive neuroscience. Journal of Mathematical Psychology. [PDF]

Annis, J., Miller, B.J., & Palmeri, T.J. (in press). Bayesian inference with Stan: A tutorial on adding custom distributions. Behavioral Research Methods. [PDF]

Ross, D.A., & Palmeri, T.J. (in press). The importance of formalizing computational models of face adaptation aftereffects. Frontiers in Psychology. [PDF]

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Mike Mack accepts faculty position at the University of Toronto

Posted on Jun 5, 2016

Mike will begin this fall as an assistant professor in the Department of Psychology at the University of Toronto. The University of Toronto is one of the oldest and most distinguished departments of psychology in the world.

Mike earned his PhD from our lab and has been a postdoctoral fellow at the University of Texas for the past several years. At Vanderbilt, Mike won the Jum Nunnally Dissertation Award, a Vanderbilt Dissertation Enhancement Grant, the Pat Burns Memorial Student Research Award, the William F. Hodges Teaching Assistant Award, and was a Learning Sciences Institute Fellow. During his postdoctoral fellowship, he has been funded by an NIH NRSA grant, he was an OPAM conference organizer, and a Memory Disorders Research Society organizer. Mike has published papers in JEP:General, JEP:HPP, Current Biology, Psychonomic Bulletin & Review, Journal of Vision, Vision Research, and several other journals and other publication outlets. His research combines behavioral experiments, functional brain imaging, and computational modeling to study human learning, memory, and categorization.

We all wish Mike the best of success in his new faculty position.

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May Shen wins Lisa M. Quesenberry Foundation Award

Posted on May 30, 2016

We congratulate Jianhong (May) Shen as the 2016 winner of The Lisa M. Quesenberry Foundation Award. This was established by Irvin and Mary Ann Quesenberry and Kathryn Quesenberry to memorialize the accomplishments of their daughter and sister, Lisa M. Quesenberry. It is designed to provide research or study awards to motivated graduate students. Preferably, the awards will be made to female graduate students who are studying the field of psychology and who have overcome significant personal challenges to pursue their education. Congratulations May!

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Julie Schnur awarded Founder’s Medal for First Honors in Engineering

Posted on May 13, 2016

Today, Julie Schnur received her Bachelor’s of Engineering in Biomedical Engineering with a minor in Scientific Computing. Julie has worked for the past year as an undergraduate research assistant in the lab under the direct supervision of postdoctoral fellow Brent Miller. At today’s graduation ceremonies, Julie was honored with the Founder’s Medal for First Honors in Engineering, the highest honor bestowed on a graduate of Vanderbilt. A link to the details can be found at http://news.vanderbilt.edu/2016/05/founders-medalists-honored-at-vanderbilt-commencement/.

This is the second year in a row that an undergraduate researcher in the lab has been so honored; last year’s winner of the Founder’s Medal in Engineering was our own Akash Umakantha.

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May Shen and Jeff Annis win Young Scientist Travel Awards

Posted on Apr 12, 2016

Congratulations to May and Jeff on each being awarded 2016 Young Scientist Travel Awards to the Annual Meeting of the Society for Mathematical Psychology. The award provides $1000 in travel allowance to the society meeting this summer at Rutgers University.

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Research Experience for Undergraduates (REU Summer 2016)

Posted on Oct 6, 2015

We are looking for outstanding students interested in a Research Experience for Undergraduates (REU) at the CatLab at Vanderbilt University this summer 2016. Our REU is part of an NSF-funded project entitled Perceptual Categorization in Real-World Expertise. This project uses online behavioral experiments to understand the temporal dynamics of perceptual expertise, measuring and manipulating the dynamics of object recognition and categorization at different levels of abstraction and assessing how those dynamics vary over measured levels of expertise, using computational models to test hypotheses about expertise mechanisms. Students have opportunities to work on projects ranging from the development of online experiments, development of analysis routines, and development and testing of computational models. This REU is especially appropriate for students interested in applying to graduate programs in psychology, vision science, cognitive science, or neuroscience. The REU provides a $5000 summer stipend, $500 per week for ten weeks; an additional $150 per week helps offsets the cost of housing and meals; a $250 travel allowance is also provided. REUs are restricted to undergraduate students currently enrolled in a degree program and must be U.S. citizens, U.S. nationals, or permanent residents of the United States.

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PEN XXX Reunion Meeting

Posted on May 20, 2015

The Perceptual Expertise Network celebrated its 30th workshop by inviting current PEN members, previous PEN members, and PEN friends to a day of talks as well as a reunion dinner following the talks. This was held on May 14th, 2015 at the TradeWinds Island Grand Resort in St. Pete Beach, Florida, as a satellite to the annual VSS conference.

Speakers at PEN XXX were:
Thomas Palmeri (Vanderbilt), Opening remarks
Marlene Berhmann (Carnegie Mellon), Never the twain shall meet
Kim Curby (Macquarie University), Are faces super objects? Object-based benefits support holistic perception
Lisa Scott (UMass Amherst), How learning during infancy enhances and constrains brain and behavioral development
Bruno Rossion (University of Louvain), Understanding expertise in face perception with fast periodic visual stimulation
Suzy Scherf (Penn State), Puberty makes us different kinds of face experts
Jim Tanaka (Victoria), Bridging the expertise gap: From the laboratory to the real world
Mike Mack (UT Austin), The evolution of category knowledge: Linking learning models to the dynamics of neural representations
Jennifer Richler (Vanderbilt), Measuring individual differences in high-level vision in a latent-variables framework
Ben Cipollini (UCSD), Exploring anatomy and genetics of cortical asymmetries
Isabel Gauthier (Vanderbilt), 15 years of fMRI studies of expertise
Michael Tarr (Carnegie Mellon), Closing talk

Photos from the workshop can be found here:
http://catlab.psy.vanderbilt.edu/palmeri/public/PEN-XXX/album/index.html

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Akash Umakantha wins Founder’s Medal

Posted on May 8, 2015

The Founder’s Medal is the top honor given to a graduate of Vanderbilt University. Cornelius Vanderbilt’s gifts to the university included endowment of this award, given since 1877 for first honors in each graduating class. Akash Umakantha, who has been working in the CatLab since the end of his freshman year, is this year’s recipient from the School of Engineering at Vanderbilt. Congratulations Akash!

Akash Umakantha, from West Chester, Ohio, is Founder’s Medalist for the School of Engineering. He graduated with a bachelor of engineering in electrical and biomedical engineering. Umakantha has been a researcher at Cold Spring Harbor Laboratory, the Vanderbilt Radiation Effects and Reliability Group and the Vanderbilt Department of Psychology. He has presented his research on models of decision-making at two international conferences. Working in Professor of Psychology Tom Palmeri’s laboratory after freshman year, he learned about mathematical models of decision-making and how to simulate complex mathematical equations on a computer. That experience inspired him to pursue an academic career in neuroscience and scientific computing. Umakantha served as an engineering tutor, and he volunteered in a 6th grade classroom through Vanderbilt Student Volunteers for Science. He is a member of engineering honor society Tau Beta Pi. Next fall, Umakantha will attend Carnegie Mellon University to pursue doctoral studies in neural computation and machine learning.

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Jennifer Richler co-winner of the Bob Fox Award of Excellence in Post-Doctoral Research

Posted on Apr 21, 2015

The Bob Fox Award of Excellence in Post-Doctoral Research is granted to post-doctoral fellows in the Department of Psychology at Vanderbilt who have demonstrated outstanding achievement in research; it is named in honor of Robert “Bob” Fox for his essential role in guiding the evolution of Vanderbilt’s Psychology Department over a five-decade period starting in the mid-60s.

Jenn earned her PhD at Vanderbilt with Isabel Gauthier and Thomas Palmeri and has continued on at Vanderbilt as a post-doctoral fellow. She previously won the Nunnally Dissertation Award and the Pat Burns Graduate Student Research Award from the department. She has 30 peer-reviewed publications and is an Associate Editor at JEP:General. She also spearheaded the PeePs (Particularly Exciting Experiments in Psychology) newsletter that highlights research published in the six experimental psychology journals from APA.

Congratulations, Jenn!

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May Shen co-winner of The William F. Hodges Teaching Assistant Award

Posted on Apr 21, 2015

The William F. Hodges Teaching Assistant Award recognizes outstanding achievement as a teaching assistant by a graduate student in the Department of Psychology at Vanderbilt. William Hodges was an undergraduate and a graduate student at Vanderbilt in the 1960s. After his untimely death in 1992, family and friends established the William F. Hodges Teaching Assistant Award at Vanderbilt to honor outstanding teaching assistants in the department.

May is a third year graduate student in the CatLab. She has completed a Certificate in College Teaching from the Center for Teaching and has TAed for a wide array of courses in the department, including PSY208 (Principles of Experimental Design), PSY209 (Quantitative Methods), and PSY225 (Cognitive Psychology); this semester, she is TAing for a statistics course in Psychology and Human Development. Adriane Seiffert, for whom May TAed in PSY208 and PSY209, noted that her work was “exemplary in both courses”, and that students commented that “she was responsive and helpful – gave exact answers to questions”, “conveyed the material in a way she knew would be effective, logical and memorable”. Geoff Woodman, for whom May TAed in PSY225, noted that she “jumped on a week’s worth of lectures when given the opportunity.”

Congratulations, May!

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New paper in Journal of Experimental Psychology: General

Posted on Mar 24, 2015

We have a new paper in press:

Mack, M.L., & Palmeri, T.J. (in press). The dynamics of categorization: Unraveling rapid categorization. Journal of Experimental Psychology: General. [PDF]

We explore a puzzle of visual object categorization: Under normal viewing conditions, you spot something as a dog fastest, but at a glance, you spot it faster as an animal. During speeded category verification, a classic basic-level advantage is commonly observed (Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976), with categorization as a dog faster than as an animal (superordinate) or Golden Retriever (subordinate). A different story emerges during ultra-rapid categorization with limited exposure duration (<30ms), with superordinate categorization faster than basic or subordinate categorization (Thorpe, Fize, & Marlot, 1996). These two widely cited findings paint contrary theoretical pictures about the time course of object categorization, yet no study has previously investigated them together. Over five experiments, we systematically examined two experimental factors that could explain the qualitative difference in categorization across the two paradigms: exposure duration and category trial context. Mapping out the time course of object categorization by manipulating exposure duration and the timing of a post-stimulus mask revealed that brief exposure durations favor superordinate-level categorization, but with more time a basic-level advantage emerges. But this superordinate advantage was modulated significantly by target category trial context. With randomized target categories, the superordinate advantage was eliminated; and with “blocks” of only four repetitions of superordinate categorization within an otherwise randomized context, the advantage for the basic-level was eliminated. Contrary to some theoretical accounts that dictate a fixed priority for certain levels of abstraction in visual processing and access to semantic knowledge, the dynamics of object categorization are flexible, depending jointly on the level of abstraction, time for perceptual encoding, and category context.

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Research Experience for Undergraduates (REU)

Posted on Feb 9, 2015

We are looking for outstanding students interested in a Research Experience for Undergraduates (REU) at the CatLab at Vanderbilt University this summer 2015. Our REU is part of an NSF-funded project entitled Perceptual Categorization in Real-World Expertise. This project uses online behavioral experiments to understand the temporal dynamics of perceptual expertise, measuring and manipulating the dynamics of object recognition and categorization at different levels of abstraction and assessing how those dynamics vary over measured levels of expertise, using computational models to test hypotheses about expertise mechanisms. Students have opportunities to work on projects ranging from the development of online experiments, development of analysis routines, and development and testing of computational models. This REU is especially appropriate for students interested in applying to graduate programs in psychology, vision science, cognitive science, or neuroscience. The REU provides a $5000 summer stipend, $500 per week for ten weeks; an additional $150 per week helps offsets the cost of housing and meals; a $250 travel allowance is also provided. REUs are restricted to undergraduate students currently enrolled in a degree program and must be U.S. citizens, U.S. nationals, or permanent residents of the United States. Undergraduates who are students at Vanderbilt may have the opportunity to continue the REU into the 2015-16 academic year. Click on READ MORE for further details on the REU and how to apply.

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New Papers

Posted on Jan 28, 2015

New papers in press:

Palmeri, T.J., & Mack, M.L. (in press). How experimental trial context affects perceptual categorization. Frontiers in Psychology.

Logan, G.D., Yamaguchi, M., & Schall, G.D., & Palmeri, T.J. (in press). Inhibitory control in mind and brain 2.0: A blocked-input model of saccadic countermanding. Psychological Review.

Richler, J.J., Palmeri, T.J., & Gauthier, I. (in press). Holistic processing does not require configural variability. Psychonomic Bulletin & Review.

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