Dynamical mechanism for sharp orientation tuning in an integrate-and-fire model of a cortical hypercolumn
File(s)
Accepted version
Author(s)
Bressloff, PC
Bressloff, NW
Cowan, JD
Type
Journal Article
Abstract
Orientation tuning in a ring of pulse-coupled integrate-and-fire (IF) neurons is analyzed in terms of spontaneous pattern formation. It is shown how the ring bifurcates from a synchronous state to a non-phase-locked state whose spike trains are characterized by clustered but irregular fluctuations of the interspike intervals (ISIs). The separation of these clusters in phase space results in a localized peak of activity as measured by the time-averaged firing rate of the neurons. This generates a sharp orientation tuning curve that can lock to a slowly rotating, weakly tuned external stimulus. Under certain conditions, the peak can slowly rotate even to a fixed external stimulus. The ring also exhibits hysteresis due to the subcritical nature of the bifurcation to sharp orientation tuning. Such behavior is shown to be consistent with a corresponding analog version of the IF model in the limit of slow synaptic interactions. For fast synapses, the deterministic fluctuations of the ISIs associated with the tuning curve can support a coefficient of variation of order unity.
Date Issued
2000-11
Date Acceptance
2000-02-02
Citation
Neural Computation, 2000, 12 (11), pp.2473-2511
ISSN
0899-7667
Publisher
Massachusetts Institute of Technology Press
Start Page
2473
End Page
2511
Journal / Book Title
Neural Computation
Volume
12
Issue
11
Copyright Statement
© 2000 Massachusetts Institute of Technology P. C. Bressloff, N. W. Bressloff, J. D. Cowan; Dynamical Mechanism for Sharp Orientation Tuning in an Integrate-and-Fire Model of a Cortical Hypercolumn. Neural Comput 2000; 12 (11): 2473–2511. doi: https://doi.org/10.1162/089976600300014809
Identifier
http://dx.doi.org/10.1162/089976600300014809
Publication Status
Published
Date Publish Online
2000-11-01