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Stimulus fluctuations together with top-down feedback can account for the dynamics of Choice Probability in MT
Wimmer, Klaus; Wolf, Fred (2013)
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clipboard		 Wimmer K., et al. "Stimulus fluctuations together with top-down feedback can account for the dynamics of Choice Probability in MT.", timms video, Universität Tübingen (2013): https://timms.uni-tuebingen.de:443/tp/UT_20130927_005_bestcon_0001. Accessed 03 Dec 2024.
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clipboard		 Wimmer, K. & Wolf, F. (2013). Stimulus fluctuations together with top-down feedback can account for the dynamics of Choice Probability in MT. timms video: Universität Tübingen. Retrieved December 03, 2024 from the World Wide Web https://timms.uni-tuebingen.de:443/tp/UT_20130927_005_bestcon_0001
harvard
clipboard		 Wimmer, K. and Wolf, F. (2013). Stimulus fluctuations together with top-down feedback can account for the dynamics of Choice Probability in MT [Online video]. 27 September. Available at: https://timms.uni-tuebingen.de:443/tp/UT_20130927_005_bestcon_0001 (Accessed: 3 December 2024).
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title: Stimulus fluctuations together with top-down feedback can account for the dynamics of Choice Probability in MT
alt. title: Bernstein Conference 2013: Cortical Dynamics and Circuits
creators: Wimmer, Klaus (author), Wolf, Fred (annotator)
subjects: Bernstein Conference, Computational Neuroscience, Cortical Dynamics and Circuits, Stimulus Fluctuations, Top-Down Feedback, Dynamics of Choice Probability in MT, Klaus Wimmer
description: Bernstein Conference 2013, 24. bis 27. September 2013
abstract: Single neuron variability is correlated with variability in perceptual decisions [1]. This relationship can be quantified by choice probability (CP) and has commonly been interpreted as evidence for correlated noise in sensory circuits biasing decisions [2]. However, while choice probability is typically sustained throughout the trial, the impact of stimulus fluctuations on the decision decreases over time, questioning the causal role of fluctuations on the decision [3,4]. Here, we address this paradox while seeking a unified understanding of how stimulus, neuronal, and behavioral fluctuations give rise to correlations and CP in plausible cortical circuits. We developed a network model of a sensory (MT) and a decision circuit with attractor dynamics (LIP). If identical stimuli were used, the average correlation between neurons could be very small - despite substantial shared input - yielding chance-level CPs. Stimulus fluctuations gave rise to spurious correlations which caused significant CP early in the trial. Adding top-down connections between LIP and MT could parsimoniously reproduce the experimentally observed sustained time-course of CPs. The model makes several predictions which we confirmed in the data from a classical experiment [1,5]: (1) Stimulus fluctuations substantially increased the variability of MT neurons measured by the Fano factor. (2) Average CP exhibited a significant reduction in the early part for identical stimuli. (3) Choice-conditioned correlations for preferred choice trials decreased throughout the trial. (4) CP time courses of single neurons were heterogeneous and consistent with an underlying bottom-up and top-down component. Our findings suggest that correlations and CP in MT can partly be attributed to stimulus fluctuations and variability of top-down signals reflecting the upcoming decision. The model prompts for a revision of the potential sources of correlations in sensory circuits. References [1] Britten, K. H., Newsome, W. T., Shadlen, M. N., Celebrini, S. and Movshon, J. A., Vis Neurosci (1996). [2] Shadlen, M. N., Britten, K. H., Newsome, W. T. and Movshon, J. A., J Neurosci (1996). [3] Kiani, R., Hanks, T. D. and Shadlen, M. N., J Neurosci (2008). doi:10.1523/JNEUROSCI.4761-07.2008 [4] Nienborg, H. and Cumming, B. G., Nature (2009). doi:10.1038/nature07821 [5] Zohary, E., Shadlen, M. N. and Newsome, W. T., Nature (1994).
publisher: ZDV Universität Tübingen
contributors: Bernstein Center for Computational Neuroscience Tübingen (BCCN) (producer), Bethge, Matthias (organizer), Wichmann, Felix (organizer), Lam, Judith (organizer), Macke, Jakob (organizer)
creation date: 2013-09-27
dc type: image
localtype: video
identifier: UT_20130927_005_bestcon_0001
language: eng
rights: Url: https://timmsstatic.uni-tuebingen.de/jtimms/TimmsDisclaimer.html?638688490876616052