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[{"key": "dc.contributor.advisor", "value": "Nokelainen, Ossi", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.advisor", "value": "Valkonen, Janne", "language": "", "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.author", "value": "Silvasti, Sanni", "language": "", "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2020-05-06T12:49:34Z", "language": null, "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2020-05-06T12:49:34Z", "language": null, "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2020", "language": "", "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/68865", "language": null, "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "El\u00e4inten v\u00e4rin\u00e4k\u00f6\u00e4 tutkitaan n\u00e4k\u00f6malleilla, joilla voidaan p\u00e4\u00e4tell\u00e4 kohdelajin herkkyytt\u00e4 n\u00e4hd\u00e4 eri v\u00e4rej\u00e4. Mallit laskevat niin kutsuttuja JND-arvoja (just-noticeable-difference), jotka kertovat, kuinka pienen v\u00e4rieron 75 % lajin yksil\u00f6ist\u00e4 pystyy erottamaan taustasta. JND:n laskemisessa mallit k\u00e4ytt\u00e4v\u00e4t v\u00e4rikohtaisia Weberin fraktioita m\u00e4\u00e4ritt\u00e4m\u00e4\u00e4n raja-arvot v\u00e4rien erottelukyvylle. Vaikka n\u00e4k\u00f6malleja k\u00e4ytet\u00e4\u00e4n laajalti, useimpien el\u00e4inlajien Weberin fraktioita ei tunneta, joten n\u00e4k\u00f6mallinnuksessa niist\u00e4 k\u00e4ytet\u00e4\u00e4n yleisi\u00e4 olettamuksia. Tutkielmassani m\u00e4\u00e4rit\u00e4n tarkat Weberin fraktiot sinitiaiselle punaisessa, vihre\u00e4ss\u00e4, sinisess\u00e4 ja akromaattisessa v\u00e4rikanavassa valkoista testitaustaa vasten. Tutkin my\u00f6s, miten m\u00e4\u00e4ritetyt Weberin fraktiot kuvailevat sinitiaisen saalistusk\u00e4yt\u00f6st\u00e4 ja testaan, miten taustan kromaattinen monimutkaisuus vaikeuttaa saaliin etsint\u00e4\u00e4. Tutkimuskysymykset ovat i) mitk\u00e4 Weberin fraktiot parhaiten kuvailevat sinitiaisen v\u00e4rien erotusrajoja, ii) miten siirtym\u00e4t v\u00e4riavaruudessa (s\u00e4vyn muutokset) vaikuttavat \u00e4rsykkeiden etsimiseen, ja iii) miten v\u00e4reill\u00e4 ja muodoilla luotu kohina vaikuttaa saaliin etsint\u00e4\u00e4n v\u00e4rikanavissa? Valkoista taustaa vasten m\u00e4\u00e4ritetyt Weberin fraktiot olivat pun: 0,05; vihr: 0,03 ja sin: 0,03. N\u00e4m\u00e4 fraktiot eiv\u00e4t kuvailleet sinitiaisten k\u00e4yt\u00f6st\u00e4 v\u00e4rikyll\u00e4isill\u00e4 taustoilla, joilla oikeat Weberin fraktiot olivat pun: 0,20; vihr: 0,17 ja sin: 0,15. Taustan kromaattinen monimutkaisuus heikensi \u00e4rsykkeiden l\u00f6yt\u00e4mist\u00e4 vain punaisessa v\u00e4rikanavassa. Tulosteni perusteella varoitan, ett\u00e4 v\u00e4ritt\u00f6m\u00e4ll\u00e4 taustalla mitatut Weberin fraktiot saattavat n\u00e4k\u00f6mallinnuksessa tuottaa harhaanjohtavia tuloksia, jos mallinnusta k\u00e4ytet\u00e4\u00e4n luonnonmukaiseen \u2013 v\u00e4rilliseen \u2013 maailmaan.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Animal colour vision is studied through vision models. These models give us information on how colour is perceived in the retina of study subject. Vision models provide us the smallest colour difference that 75 % of individuals in a species are assumed to distinguish (just-noticeable-difference). To determine JND values, the models use Weber fractions that set discrimination thresholds of a stimulus compared to its background. Albeit vision models are widely used, they use assumptions of Weber fractions since the exact fractions are unknown for most species. Here, I determine Weber fractions for blue tit (Cyanistes caeruleus) long-, middle-, short-wave (i.e. L, M, S: red, green, blue, respectively) and achromatic channels, examine how Weber fractions describe blue tit prey search behaviour and test how chromatic complexity impairs stimulus search. More specifically, I ask: i) which Weber fractions in different colour channels best describe blue tit colour discrimination, ii) how peripheral shifts in colour space (i.e. changes in hue) influence signal search behaviour, and iii) how background noise impairs signal search behaviour through colour channels? The Weber fractions that best described blue tit colour discrimination against achromatic background were L: 0.05, M: 0.03 and S: 0.03. In contrast, these values did not describe blue tit colour discrimination on saturated chromatic backgrounds, whereas Weber fractions L: 0.20, M: 0.17 and S: 0.15 did. Chromatic complexity of backgrounds affected the long-wave channel, while middle- and short-wave channels were mostly unaffected. I conclude by warning, that careless use of Weber fractions in vision modelling may provide misleading interpretations in biologically relevant context as they are often used.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by Paivi Vuorio (paelvuor@jyu.fi) on 2020-05-06T12:49:34Z\nNo. of bitstreams: 0", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2020-05-06T12:49:34Z (GMT). No. of bitstreams: 0\n Previous issue date: 2020", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.format.extent", "value": "49", "language": "", "element": "format", "qualifier": "extent", "schema": "dc"}, {"key": "dc.format.mimetype", "value": "application/pdf", "language": null, "element": "format", "qualifier": "mimetype", "schema": "dc"}, {"key": "dc.language.iso", "value": "eng", "language": null, "element": "language", "qualifier": "iso", "schema": "dc"}, {"key": "dc.rights", "value": "In Copyright", "language": "en", "element": "rights", "qualifier": null, "schema": "dc"}, {"key": "dc.subject.other", "value": "colour vision", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "discrimination thresholds", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "vision models", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "vision testing", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.title", "value": "Behavioural thresholds of blue tit colour vision and the effect of chromatic complexity in finding prey", "language": "", "element": "title", "qualifier": null, "schema": "dc"}, {"key": "dc.type", "value": "master thesis", "language": null, "element": "type", "qualifier": null, "schema": "dc"}, {"key": "dc.identifier.urn", "value": "URN:NBN:fi:jyu-202005063076", "language": "", "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Pro gradu -tutkielma", "language": "fi", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Master\u2019s thesis", "language": "en", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Matemaattis-luonnontieteellinen tiedekunta", "language": "fi", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Faculty of Sciences", "language": "en", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Bio- ja ymp\u00e4rist\u00f6tieteiden laitos", "language": "fi", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Department of Biological and Environmental Science", "language": "en", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Ekologia ja evoluutiobiologia", "language": "fi", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Ecology and evolutionary biology", "language": "en", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "yvv.contractresearch.funding", "value": "0", "language": "", "element": "contractresearch", "qualifier": "funding", "schema": "yvv"}, {"key": "dc.type.coar", "value": "http://purl.org/coar/resource_type/c_bdcc", "language": null, "element": "type", "qualifier": "coar", "schema": "dc"}, {"key": "dc.rights.accesslevel", "value": "restrictedAccess", "language": null, "element": "rights", "qualifier": "accesslevel", "schema": "dc"}, {"key": "dc.type.publication", "value": "masterThesis", "language": null, "element": "type", "qualifier": "publication", "schema": "dc"}, {"key": "dc.subject.oppiainekoodi", "value": "4011", "language": "", "element": "subject", "qualifier": "oppiainekoodi", "schema": "dc"}, {"key": "dc.subject.yso", "value": "v\u00e4rit", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "n\u00e4k\u00f6", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "sinitiainen", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "valo", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "linnut", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "havainnot", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "colours", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "eyesight", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "blue tit", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "light (electromagnetic radiation)", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "birds", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "perceptions (mental objects)", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.format.content", "value": "fulltext", "language": null, "element": "format", "qualifier": "content", "schema": "dc"}, {"key": "dc.rights.url", "value": "https://rightsstatements.org/page/InC/1.0/", "language": null, "element": "rights", "qualifier": "url", "schema": "dc"}, {"key": "dc.rights.accessrights", "value": "The author has not given permission to make the work publicly available electronically. Therefore the material can be read only at the archival workstation at Jyv\u00e4skyl\u00e4 University Library (https://kirjasto.jyu.fi/en/workspaces/facilities).", "language": "en", "element": "rights", "qualifier": "accessrights", "schema": "dc"}, {"key": "dc.rights.accessrights", "value": "Tekij\u00e4 ei ole antanut lupaa avoimeen julkaisuun, joten aineisto on luettavissa vain Jyv\u00e4skyl\u00e4n yliopiston kirjaston arkistoty\u00f6semalta. Ks. https://kirjasto.jyu.fi/fi/tyoskentelytilat/laitteet-ja-tilat..", "language": "fi", "element": "rights", "qualifier": "accessrights", "schema": "dc"}, {"key": "dc.type.okm", "value": "G2", "language": null, "element": "type", "qualifier": "okm", "schema": "dc"}]
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