Open Source


Karr, J. E., Areshenkoff, C. N., Rast, P., Iverson, G.L., & Garcia-Barrera, M. A. (2018). The Unity and Diversity of Executive Functions: A Systematic Review and Re-Analysis of Latent Variable Studies. Psychological Bulletin.
[Link][Data and Code]

Trafimow, D., Amrhein, V., Areshenkoff, C. N., Barrera-Causil, C. J., Beh, E. J., BilgiƧ, Y. K., … & Chaigneau, S. E. (2018). Manipulating the Alpha Level Cannot Cure Significance Testing. Frontiers in Psychology, 9, 699.

Areshenkoff, C. N., Bub, D. N., & Masson, M. E. (2017). Task-dependent motor representations evoked by spatial words: Implications for embodied accounts of word meaning. Journal of Memory and Language, 92, 158-169.

Smart, C. M., Karr, J. E., Areshenkoff, C. N., Rabin, L. A., Hudon, C., Gates, N., … & Hampel, H. (2017). Non-pharmacologic interventions for older adults with subjective cognitive decline: systematic review, meta-analysis, and preliminary recommendations. Neuropsychology review, 27(3), 245-257.
[Link][Data and Code]

Karr, J. E., Areshenkoff, C. N., Duggan, E. C., & Garcia-Barrera, M. A. (2014). Blast-related mild traumatic brain injury: a Bayesian random-effects meta-analysis on the cognitive outcomes of concussion among military personnel. Neuropsychology review, 24(4), 428-444.

Karr, J. E., Areshenkoff, C. N., Rast, P., & Garcia-Barrera, M. A. (2014). An empirical comparison of the therapeutic benefits of physical exercise and cognitive training on the executive functions of older adults: A meta-analysis of controlled trials. Neuropsychology, 28(6), 829.

Karr, J. E., Areshenkoff, C. N., & Garcia-Barrera, M. A. (2014). The neuropsychological outcomes of concussion: A systematic review of meta-analyses on the cognitive sequelae of mild traumatic brain injury. Neuropsychology, 28(3), 321.

Karr, J. E., Garcia-Barrera, M. A., & Areshenkoff, C. N. (2014). Executive functions and intraindividual variability following concussion. Journal of clinical and experimental neuropsychology, 36(1), 15-31.


I generally make an effort to bundle most of the code that I use repeatedly into packages for reusability. Many of them are works in progress, and only SPDM is in a more or less finished state.


Operations on the Riemannian manifold of symmetric, positive definite matrices (aka covariance matrices). Includes tools for estimation, interpolation, distance and mean calculations, and kernel methods.

Motion Toolkit

A side project of mine for the last while has been the development of a pipeline for the statistical analysis of three dimensional motion trajectory data, including both position and rotation, using dual quaternions. The motion toolkit so far includes a package seathree, which implements basic operations on dual quaternions, and seacurve (in progress), implementing an R6 class representing a three dimensional motion trajectory as a smooth dual quaternion curve. Also included is a package motionImport which allows importing a motion trial data from the .exp files exported by the motion monitor system in our lab, though this is unlikely to be of use to anyone with a different system. More details can be found on the project page.


R package implementing several forms of low rank matrix approximation, including an expanded version of the Population Value Decomposition (PVD) implemented by rTensor and proposed by Crainiceanu et al (2013), and several forms of generalized low rank approximation of matrices (GLRAM).


Weighted and unweighted symmetric nonnegative matrix factorization for undirected graph clustering.