Neural circuit dynamics underlying accumulation of time-varying evidence during perceptual decision making
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Program in Applied and Computational Mathematics, Center for the Study of Brain, Mind and Behavior, Princeton University, USA
- 2
Section of Neurobiology, Center for Perceptual Systems, Institute for Neuroscience, The University of Texas at Austin, USA
- 3
Howard Hughes Medical Institute, Department of Physiology and Biophysics, University of Washington, USA
- 4
Department of Neurobiology, Kavli Institute for Neuroscience, Yale University School of Medicine, USA
How do neurons in a decision circuit integrate time-varying signals, in favor of or against alternative choice options? To address this question, we used a recurrent neural circuit model to simulate an experiment in which monkeys performed a direction-discrimination task on a visual motion stimulus. In a recent study, it was found that brief pulses of motion perturbed neural activity in the lateral intraparietal area (LIP), and exerted corresponding effects on the monkeyquotidns choices and response times. Our model reproduces the behavioral observations and replicates LIP activity which, depending on whether the direction of the pulse is the same or opposite to that of a preferred motion stimulus, increases or decreases persistently over a few hundred milliseconds. Furthermore, our model accounts for the observation that the pulse exerts a weaker influence on LIP neuronal responses when the pulse is late relative to motion stimulus onset. We show that this violation of time-shift invariance (TSI) is consistent with a recurrent circuit mechanism of time integration. We further examine time integration using two consecutive pulses of the same or opposite motion directions. The induced changes in the performance are not additive, and the second of the paired pulses is less effective than its standalone impact, a prediction that is experimentally testable. Taken together, these findings lend further support for an attractor network model of time integration in perceptual decision making.
Keywords:
intraparietal cortex, reaction time, computational modeling, attractor network, visual motion discrimination
Citation:
Kong-Fatt Wong, Alexander C. Huk, Michael N. Shadlen and Xiao-Jing Wang (2007). Neural circuit dynamics underlying accumulation of time-varying evidence during perceptual decision making. Front. Comput. Neurosci. 1:6. doi: 10.3389/neuro.10/006.2007
Received: 7 September 2007;
Paper pending published: 9 October 2007;
Accepted: 13 October 2007;
Published online: 2 November 2007
Edited by:
Misha Tsodyks, Weizmann Institute of Science, Israel
Reviewed by:
Walter Senn, University of Bern, Switzerland
Harel Z. Shouval, University of Texas, Medical School at Houston, USA
Copyright:
© 2007 Wong, Huk, Shadlen, Wang. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence:
Xiao-Jing Wang, Department of Neurobiology, Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA. e-mail: xjwang@yale.edu