Categorization is among the most important cognitive skills that humans possess. It allows us to navigate in a dangerous world, and to find food, shelter, and friends. The evidence is now overwhelming that humans have multiple category-learning systems, which are largely neuroanatomically separate, learn by qualitatively different rules, and have adapted to learning different types of category structures. A natural next question to investigate is how these various systems interact. This is an important problem because during daily life we must often switch between different categorization systems (e.g., explicit and procedural). For example, many components of driving are procedural, but at the same time some explicit decisions are required. Following an explicit decision, a failure to quickly switch back to a procedural strategy could greatly increase the risk of an accident. The proposed research studies how explicit and procedural category learning are coordinated and how control is transferred between these systems. We take an integrative, cross-disciplinary, converging operations approach that combines behavioral, neuropsychological (with Parkinson's disease patients), functional magnetic resonance imaging, and transcranial magnetic stimulation studies with the goal of building and testing biologically detailed computational models of the brain circuits that mediate categorization and system-switching behavior. This proposal is to continue a program that (a) provided much of the existing evidence that humans have multiple category-learning systems, (b) mapped out the neural networks that mediate each system, and (c) discovered many unique properties of these systems. During the previous period (2R01 MH3760), we made significant progress in several areas. One was to understand how learning in the various systems is coordinated. Toward this end, we reported evidence that trial-by-trial switching between explicit and procedural categorization strategies is extremely difficult. The proposed research, which continues our investigations of system interactions, has three aims.
Aim 1 is to identify the cognitive components of system switching.
Aim 2 is to identify the neural basis of system switching, and Aim 3 is to develop and test a biologically detailed computational model of system switching. The model we develop should be able to provide accurate accounts of all data from Aims 1 and 2, as well as data from various published single-unit recording studies. In addition, the model will make specific predictions about how drugs, genes, and focal lesions should affect behavior and it will make novel predictions about behavioral and pharmacological interventions that might improve system switching in category learning.

Public Health Relevance

This research has important health relevance because category learning is compromised during normal aging and in a wide variety of neuropsychological disorders, including Parkinson's disease, schizophrenia, Huntington's disease, autism, and early Alzheimer's disease, to name a few. In addition, this work will further our understanding of the functional role of the subthalamic nucleus, which is a common target of deep brain stimulation as a treatment for Parkinson's disease. It could also help identify neuropsychological conditions that are susceptible to problems in switching between explicit and implicit (e.g., motor memories) skills.

National Institute of Health (NIH)
National Institute of Mental Health (NIMH)
Research Project (R01)
Project #
Application #
Study Section
Cognition and Perception Study Section (CP)
Program Officer
Rossi, Andrew
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of California Santa Barbara
Schools of Arts and Sciences
Santa Barbara
United States
Zip Code
Sajedinia, Zahra; Hélie, Sébastien (2018) A New Computational Model for Astrocytes and Their Role in Biologically Realistic Neural Networks. Comput Intell Neurosci 2018:3689487
Crossley, Matthew J; Roeder, Jessica L; Helie, Sebastien et al. (2018) Trial-by-trial switching between procedural and declarative categorization systems. Psychol Res 82:371-384
Hélie, Sébastien; Fansher, Madison (2018) Categorization system-switching deficits in typical aging and Parkinson's disease. Neuropsychology 32:724-734
Crossley, Matthew J; Maddox, W Todd; Ashby, F Gregory (2018) Increased cognitive load enables unlearning in procedural category learning. J Exp Psychol Learn Mem Cogn 44:1845-1853
Soto, Fabian A; Zheng, Emily; Fonseca, Johnny et al. (2017) Testing Separability and Independence of Perceptual Dimensions with General Recognition Theory: A Tutorial and New R Package (grtools). Front Psychol 8:696
Cantwell, George; Riesenhuber, Maximilian; Roeder, Jessica L et al. (2017) Perceptual category learning and visual processing: An exercise in computational cognitive neuroscience. Neural Netw 89:31-38
Filoteo, J Vincent; Maddox, W Todd; Ashby, F Gregory (2017) Quantitative modeling of category learning deficits in various patient populations. Neuropsychology 31:862-876
Hélie, Sébastien; Shamloo, Farzin; Novak, Keisha et al. (2017) The roles of valuation and reward processing in cognitive function and psychiatric disorders. Ann N Y Acad Sci 1395:33-48
Hélie, Sébastien; Turner, Benjamin O; Crossley, Matthew J et al. (2017) Trial-by-trial identification of categorization strategy using iterative decision-bound modeling. Behav Res Methods 49:1146-1162
Hélie, Sébastien (2017) Practice and Preparation Time Facilitate System-Switching in Perceptual Categorization. Front Psychol 8:1964

Showing the most recent 10 out of 30 publications