Saccadic suppression by way of retinal image processing

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dc.contributor.advisor Hafed, Ziad (Prof. Dr.)
dc.contributor.author Idrees, Saad
dc.date.accessioned 2021-08-13T08:15:52Z
dc.date.available 2021-08-13T08:15:52Z
dc.date.issued 2021-08-13
dc.identifier.uri http://hdl.handle.net/10900/117891
dc.identifier.uri http://nbn-resolving.de/urn:nbn:de:bsz:21-dspace-1178916 de_DE
dc.identifier.uri http://dx.doi.org/10.15496/publikation-59266
dc.description.abstract Humans make eye movements such as saccades four times every second. Saccades disrupt the visual flow on the retina; however, visual perception remains a stable and coherent process. This is a striking achievement of the visual system. Visual stability around the time of these eye movements is partially associated with a reduction in visual sensitivity, a phenomenon known as saccadic suppression. While saccadic suppression has been extensively characterized at the perceptual and neural levels, its underlying mechanisms remain elusive. According to the favored view, eye-movement related signals play a central role in the genesis of saccadic suppression. Despite extensive efforts to substantiate these claims, the neural origin of such signals has not been established. In this dissertation, we challenge the dominant view that saccadic suppression is triggered by eye-movement related signals. Instead, using electrophysiology in mouse, pig, and macaque retina, 2-photon calcium imaging, computational modeling, and human psychophysics we show evidence that visual mechanisms starting at the retina account for perceptual saccadic suppression. Cellular and circuit level descriptions of these retinal mechanisms are presented in detail. Most notably, we find a novel retinal processing motif underlying retinal saccadic suppression, “dynamic reversal suppression”, which is triggered by sequential stimuli containing contrast reversals. This motif does not involve inhibition but relies on nonlinear transformation of the inherently slow responses of cone photoreceptors by downstream retinal pathways. We also found that eye-movement related signals act to shorten the suppression resulting from visual mechanisms - a diametrically opposite involvement of eye movement signals than proposed in the literature. Overall, our results establish a neural locus of saccadic suppression, and provide detailed mechanistic insights underlying it. These findings resolve a long-standing open question concerning the origin of saccadic suppression. Given that the retinal saccadic suppression is triggered by sequential visual stimulation, our results also describe retinal processing of dynamic stimuli. en
dc.language.iso en de_DE
dc.publisher Universität Tübingen de_DE
dc.rights ubt-podok de_DE
dc.rights.uri http://tobias-lib.uni-tuebingen.de/doku/lic_mit_pod.php?la=de de_DE
dc.rights.uri http://tobias-lib.uni-tuebingen.de/doku/lic_mit_pod.php?la=en en
dc.subject.classification Retina, eye, electrophysiology, vision de_DE
dc.subject.ddc 000 de_DE
dc.subject.ddc 500 de_DE
dc.subject.ddc 570 de_DE
dc.subject.other saccadic suppression en
dc.subject.other visual perception en
dc.subject.other saccades en
dc.subject.other retinal ganglion cells en
dc.subject.other dynamic reversal suppression en
dc.title Saccadic suppression by way of retinal image processing de_DE
dc.type Dissertation de_DE
dcterms.dateAccepted 2020-11-23
utue.publikation.fachbereich Biologie de_DE
utue.publikation.fakultaet 7 Mathematisch-Naturwissenschaftliche Fakultät de_DE
utue.publikation.noppn yes de_DE

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