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dc.contributor.authorWheat, HE
dc.contributor.authorGoodwin, AW
dc.identifierpii: 21/19/7751
dc.identifier.citationWheat, H. E. & Goodwin, A. W. (2001). Tactile discrimination of edge shape: Limits on spatial resolution imposed by parameters of the peripheral neural population. JOURNAL OF NEUROSCIENCE, 21 (19), pp.7751-7763.
dc.descriptionC1 - Journal Articles Refereed
dc.description.abstractWhen the flat faces of a coin are grasped between thumb and index finger, a "curved edge" is felt. Analogous curved edges were generated by our stimuli, which comprised the flat face of segments of annuli applied passively to immobilized fingers. Humans could scale the curvature of the annulus and could discriminate changes in curvature of approximately 20 m(-1). The responses of single slowly adapting type I afferents (SAIs) recorded in anesthetized monkeys could be quantified by the product of two factors: their sensitivity and a spatial profile dependent only on the radius of the annulus. This allowed us to reconstruct realistic SAI population responses that included noise, variation in fiber sensitivity, and varying innervation patterns. The critical question was how relatively small populations ( approximately 70 active fibers) can encode edge curvature with such precision. A template-matching approach was used to establish the accuracy of edge representation in the population. The known large interfiber variability in sensitivity had no effect on curvature resolution. Neural resolution was superior to human performance until large levels of central noise were present showing that, unlike simple detection, spatial processing is limited centrally. In contrast to the behavior of mean response codes, neural resolution improved with increasing covariance in noise. Surprisingly, resolution for any single population varied considerably with small changes in the position of the stimulus relative to the SAI matrix. Overall innervation density was not as critical as the spacing of receptive fields at right angles to the edge.
dc.subjectSensory Systems; Nervous System and Disorders
dc.titleTactile discrimination of edge shape: Limits on spatial resolution imposed by parameters of the peripheral neural population
dc.typeJournal Article
melbourne.peerreviewPeer Reviewed
melbourne.affiliationThe University of Melbourne
melbourne.affiliation.departmentAnatomy And Cell Biology
melbourne.source.titleJOURNAL OF NEUROSCIENCE
melbourne.contributor.authorWHEAT, HEATHER
melbourne.contributor.authorGOODWIN, ANTONY
melbourne.accessrightsAccess this item via the Open Access location

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