Imperial College London
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Dr Kris V Parag

Faculty of Medicine, School of Public Health

Research Fellow
 
 
 
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Contact

 

k.parag

 
 
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Location

 

Wright Fleming WingSt Mary's Campus

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Summary

 

Publications

Citation

BibTex format

@article{Parag:2017:10.1371/journal.pcbi.1005687,
author = {Parag, KV and Vinnicombe, G},
doi = {10.1371/journal.pcbi.1005687},
journal = {PLoS Computational Biology},
pages = {1--25},
title = {Point process analysis of noise in early invertebrate vision},
url = {http://dx.doi.org/10.1371/journal.pcbi.1005687},
volume = {13},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Noise is a prevalent and sometimes even dominant aspect of many biological processes. While many natural systems have adapted to attenuate or even usefully integrate noise, the variability it introduces often still delimits the achievable precision across biological functions. This is particularly so for visual phototransduction, the process responsible for converting photons of light into usable electrical signals (quantum bumps). Here, randomness of both the photon inputs (regarded as extrinsic noise) and the conversion process (intrinsic noise) are seen as two distinct, independent and significant limitations on visual reliability. Past research has attempted to quantify the relative effects of these noise sources by using approximate methods that do not fully account for the discrete, point process and time ordered nature of the problem. As a result the conclusions drawn from these different approaches have led to inconsistent expositions of phototransduction noise performance.This paper provides a fresh and complete analysis of the relative impact of intrinsic and extrinsic noise in invertebrate phototransduction using minimum mean squared error reconstruction techniques based on Bayesian point process (Snyder) filters. An integrate-fire based algorithm is developed to reliably estimate photon times from quantum bumps and Snyder filters are then used to causally estimate random light intensities both at the front and back end of the phototransduction cascade. Comparison of these estimates reveals that the dominant noise source transitions from extrinsic to intrinsic as light intensity increases. By extending the filtering techniques to account for delays, it is further found that among the intrinsic noise components, which include bump latency (mean delay and jitter) and shape (amplitude and width) variance, it is the mean delay that is critical to noise performance. As the timeliness of visual information is important for real-time action, this delay could pot
AU  - Parag,KV
AU  - Vinnicombe,G
DO  - 10.1371/journal.pcbi.1005687
EP  - 25
PY  - 2017///
SN  - 1553-734X
SP  - 1
TI  - Point process analysis of noise in early invertebrate vision
T2  - PLoS Computational Biology
UR  - http://dx.doi.org/10.1371/journal.pcbi.1005687
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000414148800012&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1005687
UR  - http://hdl.handle.net/10044/1/78184
VL  - 13
ER  -
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