Title
Spike-triggered covariance: geometric proof, symmetry properties, and extension beyond Gaussian stimuli.
Abstract
The space of sensory stimuli is complex and high-dimensional. Yet, single neurons in sensory systems are typically affected by only a small subset of the vast space of all possible stimuli. A proper understanding of the input-output transformation represented by a given cell therefore requires the identification of the subset of stimuli that are relevant in shaping the neuronal response. As an extension to the commonly-used spike-triggered average, the analysis of the spike-triggered covariance matrix provides a systematic methodology to detect relevant stimuli. As originally designed, the consistency of this method is guaranteed only if stimuli are drawn from a Gaussian distribution. Here we present a geometric proof of consistency, which provides insight into the foundations of the method, in particular, into the crucial role played by the geometry of stimulus space and symmetries in the stimulus-response relation. This approach leads to a natural extension of the applicability of the spike-triggered covariance technique to arbitrary spherical or elliptic stimulus distributions. The extension only requires a subtle modification of the original prescription. Furthermore, we present a new resampling method for assessing statistical significance of identified relevant stimuli, applicable to spherical and elliptic stimulus distributions. Finally, we exemplify the modified method and compare it to other prescriptions given in the literature.
Year
DOI
Venue
2013
10.1007/s10827-012-0411-y
Journal of Computational Neuroscience
Keywords
Field
DocType
Covariance analysis,Spike-triggered average,Receptive field,Linear-nonlinear model
Combinatorics,Normal distribution,Control theory,Spike-triggered covariance,Algorithm,Spike-triggered average,Gaussian,Covariance matrix,Stimulus (physiology),Mathematics,Homogeneous space,Covariance
Journal
Volume
Issue
ISSN
34
1
1573-6873
Citations 
PageRank 
References 
12
0.80
11
Authors
2
Name
Order
Citations
PageRank
Inés Samengo1458.37
Tim Gollisch2373.50