The confusion effect in predatory neural networks

Tosh, C. R., Jackson, A. L. and Ruxton, G. D. (2006) The confusion effect in predatory neural networks. American Naturalist, 167, E52-E65. (doi: 10.1086/499413) (PMID:16670975)

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Abstract

A simple artificial neural network model of image reconstruction in sensory maps is presented to explain the difficulty predators experience in targeting prey in large groups (the confusion effect). Networks are trained to reconstruct multiple randomly conformed “retinal” images of prey groups in an internal spatial map of their immediate environment. They are then used to simulate prey targeting by predators on groups of specific conformation. Networks trained with the biologically plausible associative reward‐penalty method produce a more realistic model of the confusion effect than those trained with the popular but biologically implausible backpropagation method. The associative reward‐penalty model makes the novel prediction that the accuracy–group size relationship is U shaped, and this prediction is confirmed by empirical data gathered from interactive computer simulation experiments with humans as “predators.” The model further predicts all factors known from previous empirical work (and most factors suspected) to alleviate the confusion effect: increased relative intensity of the target object, heterogeneity of group composition, and isolation of the target. Interestingly, group compaction per se is not predicted to worsen predator confusion. This study indicates that the relatively simple, nonattentional mechanism of information degradation in the sensory mapping process is potentially important in generating the confusion effect.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Ruxton, Professor Graeme and Tosh, Dr Colin
Authors: Tosh, C. R., Jackson, A. L., and Ruxton, G. D.
College/School:College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
Journal Name:American Naturalist
Publisher:University of Chicago Press
ISSN:0003-0147
ISSN (Online):1537-5323)
Published Online:12 January 2005

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
364201A general neural-network model of the cognitive basis for the confusion effectGraeme RuxtonBiotechnology and Biological Sciences Research Council (BBSRC)BBS/B/01790Institute of Biodiversity Animal Health and Comparative Medicine