Research topics

I'm a 5th year PhD student in Ken Norman's Computational Memory lab at Princeton.

fMRI and multi-voxel pattern analysis

I've been heavily involved in efforts to analyze fMRI neuroimaging data multivariately. The basic idea is that we should be able to use machine learning tools to learn how the patterns in your brain activity indicate what you're thinking.

I've been coordinating development on the Princeton MVPA toolbox for Matlab, an open source package to facilitate these kinds of analyses. See our TiCS review for more information.

Forgetting (in progress)

For my PhD thesis, I'm working on series of behavioral and fMRI memory experiments that investigate what happens to a memory each time you only partially recollect it. Specifically, I'm trying to relate Michael Anderson's think/no-think results to our modeling work on the oscillating learning rule.

Connectionist modelling

With Ken Norman and Ehren Newman, I worked on a neural network learning algorithm that works very well at learning to pick apart similar patterns from one another, and captures a series of fiendish and counter-intuitive behavioural findings that I helped simulate.

Pittsburgh EBC fMRI analysis competition

I helped coordinate coordinated the team behind in the 2006 and 2007 DARPA-sponsored Pittsburgh EBC competition to read minds with fMRI.

Similarity structure and spatial working memory

As part of my master's thesis, I worked (with Ken Norman) on a novel multivariate method for exploratory fMRI analysis. It calculates the isomorphism between the pattern of activity in a brain region and the patterns predicted by rich psychological models. In my thesis, I show that we can better predict which location someone is covertly attending to with this multivariate 'similarity structure' method than with standard or univariate measures on a spatial working memory dataset. I also attempt to relate this to my work on temporal context and memory.

Context and free recall

I worked on a number of experiments to try and see if we could find a neural correlate of temporal context change in the brain, following on from Polyn et al (2005).

Decision-making

With Danny Oppenheimer and Anouk Schneider, I won the Society for Judgment and Decision Making's Hillel Einhorn Award for the best paper for a young investigator, for our work on VAMP, a Voting Agent Model of Preferences.

Task-switching

With Agatha Lenartowicz and others, I worked on using multi-voxel pattern analyses of fMRI to investigate theories of task-switching.

Publications

[See also: the Norman lab publications page]

Norman, K. A., Detre, G. J. & Polyn, S. M. (2008). Computational models of episodic memory. In R. Sun (ed), The Cambridge Handbook of Computational Cognitive Modeling. PDF

Schneider, A.S., Oppenheimer, D.M. & Detre, G.J. (submitted). VAMP (Voting Agent Model of Preferences): A Computational Model of Individual Multi-attribute Choice. Not available online yet.

Norman, K.A., Newman, E.L. & Detre, G.J. (2007). A neural network model of retrieval-induced forgetting. Psychological Review. PDF

Norman, K. A., Newman, E. L., Detre, G. J., & Polyn, S. M. (2006). How inhibitory oscillations can train neural networks and punish competitors. Neural Computation, 18:1577-1610 PDF

Norman, K.A., Polyn, S.M., Detre, G.J. and Haxby, J.V. (2006). Beyond mind-reading: multi-voxel pattern analysis of fMRI data. Trends in Cognitive Sciences, 10(3). PDF

Conference posters and abstracts

Detre, G.J., Polyn, S.M., Bannert, M.M., & Norman, K.A. (2007). Context in free recall - multi-voxel pattern analysis of fMRI. Poster presented at the Annual Meeting of the Society for Neuroscience, San Diego, CA (Nov, 2007). PDF

Schneider, A., Oppenheimer, D. Detre, G. (2007). Application of Voting Geometry to Multialternative Choice. Annual Meeting of the Cognitive Science Society, Nashville, Tennessee (2007).

Detre, G., Polyn, S.M., Moore, C.D., Natu, V.S., Singer, B.D., Cohen, J.D., Haxby, J.V., Norman, K.A. (2006). The Multi-Voxel Pattern Analysis (MVPA) toolbox. Poster presented at the Annual Meeting of the Organization for Human Brain Mapping (Jun 2006) PDF

Detre, G., Natu, V.S., Schneider, K., DeSimone, K., Kastner, S, Norman, K.A. (2005). Reading out the location being stored in spatial working memory with fMRI. Poster presented at the Annual meeting of the Society for Neuroscience, Washington, DC (Nov 2005). PDF

Polyn, S., Detre, G., Takerkart, S., Natu, V., Benharrosh, M., Singer, B., Cohen, J., Haxby, J., Norman, K., (2005). A Matlab-based toolbox to facilitate multi-voxel pattern classification of fMRI data. Poster presented at the Annual Meeting of the Organization of Human Brain Mapping, Toronto, Canada, (June 2005). PDF

Lenartowicz, A., Detre, G., Polyn, S., Chein, J., Yeung, N., Nystrom, L., Norman, K. A., Cohen, J. D. (2005). Characterization of brain states during task-switching using a neural network classifier. Poster presented at the Cognitive Neuroscience Society meeting, New York, NY. PDF

Norman, K., Newman, E., & Detre, G. (2004, November). Further predictions from a neural network model of retrieval induced forgetting. Poster presented at the 45th Annual Meeting of the Psychonomic Society. Minneapolis, MN. PDF

Norman, K. A., Newman, E. L., Detre, G. J., & Polyn, S.M. (2004). How theta oscillations can train neural networks and punish competitors. Cognitive Neuroscience, San Francisco, CA. PDF

Norman, K. A., Newman, E. L., Detre, G. J., & Polyn, S.M. (2004). How inhibitory oscillations can train neural networks and punish competitors. Computational and Systems Neuroscience, Cold Spring Harbor. PDF

Teaching

I've worked as the teaching assistant for:

Software

See my software page.