{"id":6020,"date":"2026-10-19T09:48:23","date_gmt":"2026-10-19T09:48:23","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-salfraedi-rebekka-hoffman\/"},"modified":"2026-10-19T09:48:23","modified_gmt":"2026-10-19T09:48:23","slug":"doktorsvorn-i-salfraedi-rebekka-hoffman","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-salfraedi-rebekka-hoffman\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed S\u00e1lfr\u00e6\u00f0i – Rebekka Hoffman"},"content":{"rendered":"
\n
\n

F\u00f6studaginn 18. jan\u00faar ver Rebekka Hoffmann doktorsritger\u00f0 s\u00edna \u00ed s\u00e1lfr\u00e6\u00f0i vi\u00f0 S\u00e1lfr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0 Snerti- og titringsskynjun og notkun \u00feeirra \u00ed skynskiptib\u00fana\u00f0i fyrir blinda og sj\u00f3nskerta. Experiments on haptic perception in relation to sensory substitution for the blind. <\/strong><\/p>\n

Andm\u00e6lendur eru dr. Jan van Erp, pr\u00f3fessor vi\u00f0 University of Twente, Hollandi, og dr. Johan Wessberg, pr\u00f3fessor vi\u00f0 H\u00e1sk\u00f3lann \u00ed Gautaborg, Sahlgrenska Akademin.\u00a0<\/p>\n

Umsj\u00f3narkennarar og lei\u00f0beinendur voru dr. \u00c1rni Kristj\u00e1nsson, pr\u00f3fessor vi\u00f0 S\u00e1lfr\u00e6\u00f0ideild, og dr. R\u00fanar Unn\u00fe\u00f3rsson, pr\u00f3fessor vi\u00f0 Verkfr\u00e6\u00f0i- og n\u00e1tt\u00faruv\u00edsindasvi\u00f0.<\/p>\n

Dan\u00edel \u00d3lason, pr\u00f3fessor og forseti\u00a0 S\u00e1lfr\u00e6\u00f0ideildar, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl.13:00.\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/p>\n

\u00c1grip af ranns\u00f3kn<\/strong><\/p>\n

Nota m\u00e1 snerti- og titringsskynjunarb\u00fana\u00f0 til \u00feess a\u00f0 b\u00e6ta fyrir skerta virkni annarra skynf\u00e6ra eins og sj\u00f3nar, heyrnar e\u00f0a jafnv\u00e6gisskyns, sem og a\u00f0 sty\u00f0ja vi\u00f0 upplifun \u00ed s\u00fdndarveruleika. \u00deessir notkunarm\u00f6guleikar lei\u00f0a til \u00feess a\u00f0 \u00fe\u00f6rf ver\u00f0ur \u00e1 a\u00f0 skilja betur grunne\u00f0li snerti- og titringsskynjunar. Me\u00f0al annars er mikilv\u00e6gt vi\u00f0 h\u00f6nnun snertiskynsb\u00fana\u00f0ar a\u00f0 \u00feekkja hversu n\u00e1l\u00e6gt tv\u00f6 titrandi \u00e1reiti geta veri\u00f0 \u00e1n \u00feess a\u00f0 \u00e1hrifum \u00feeirra s\u00e9 blanda\u00f0 saman me\u00f0 \u00fev\u00ed a\u00f0 meta n\u00e6mi fyrir titrandi \u00e1reitum me\u00f0 s\u00e1le\u00f0lisfr\u00e6\u00f0ilegum m\u00e6lingum. M\u00e6lt var hversu vel \u00fe\u00e1tttakendum gekk a\u00f0 greina \u00e1 milli tveggja titrara eftir \u00fev\u00ed hve langt var \u00e1 milli \u00feeirra \u00e1 baki \u00fe\u00e1tttakenda. Mismunandi fjarl\u00e6g\u00f0ir milli \u00e1reitanna tveggja voru pr\u00f3fa\u00f0ar (30 til 13 mm milli mi\u00f0ju titraranna, sem voru 10 mm \u00ed \u00feverm\u00e1l). Ni\u00f0urst\u00f6\u00f0ur s\u00fdndu a\u00f0 erfi\u00f0ara er a\u00f0 greina \u00e1 milli \u00e1reitanna tveggja \u00fev\u00ed n\u00e6r sem \u00feau eru hvort \u00f6\u00f0ru, en a\u00f0greiningin er samt g\u00f3\u00f0 fyrir minnsta muninn (13mm). \u00cd framhaldsranns\u00f3kn var a\u00f0greining \u00ed 4×4 fylki titrara m\u00e6ld \u00fear sem bili\u00f0 \u00e1 milli \u00feeirra var 25 mm, 20 mm, og 10 mm. Tveir titrarar hreyf\u00f0ust \u00ed hverri umfer\u00f0 og \u00e1ttu \u00fe\u00e1tttakendur a\u00f0 segja hvort s\u00e1 s\u00ed\u00f0ari var vinstra e\u00f0a h\u00e6gra megin og ofan e\u00f0a ne\u00f0an vi\u00f0 \u00feann fyrri. Ni\u00f0urst\u00f6\u00f0urnar s\u00fdna a\u00f0 eiginleikar titraranna hafa markt\u00e6k \u00e1hrif \u00e1 svarn\u00e1kv\u00e6mni. \u00dea\u00f0 \u00fe\u00fd\u00f0ir a\u00f0 taka ver\u00f0ur tillit til s\u00e9rt\u00e6kra eiginleika titrara \u00feegar snerti- og titringsskynjun er m\u00e6ld. Jafnframt s\u00fdndi ranns\u00f3knin fram \u00e1 \u00f3samhverfu \u00ed snerti- og titringsskynjun \u00fear sem a\u00f0greiningarn\u00e1kv\u00e6mni var h\u00e6rri fyrir l\u00e1r\u00e9ttan mun \u00e1 sta\u00f0setningu heldur en fyrir l\u00f3\u00f0r\u00e9ttan mun. Einnig var a\u00f0greiningarn\u00e1kv\u00e6mnin minni n\u00e1l\u00e6gt m\u00e6nunni heldur en fj\u00e6r henni \u00e1 baki \u00fe\u00e1tttakenda.<\/p>\n

Tv\u00e6r ranns\u00f3knir voru jafnframt ger\u00f0ar \u00e1 n\u00fdrri snerti-skynvillu sem lei\u00f0ir til \u00feess a\u00f0 snerting er skynju\u00f0 \u00e1 r\u00f6ngum sta\u00f0. Tv\u00e6r tegundir titrara voru pr\u00f3fa\u00f0ar \u00e1 l\u00e6gri hluta baks \u00fe\u00e1tttakenda. S\u00fdndarhreyfing var myndu\u00f0 me\u00f0 \u00fev\u00ed a\u00f0 kveikja \u00e1 tveimur titrurum me\u00f0 stuttu millibili me\u00f0 mismunandi fjarl\u00e6g\u00f0 og \u00e1tt. Einnig var breytilegt hvort fyrri og seinni titringurinn var sterkur e\u00f0a veikur. \u00de\u00e1tttakendur sv\u00f6ru\u00f0u til um skynja\u00f0a \u00e1tt \u00e1reitanna. Ranns\u00f3knin sta\u00f0festi tilvist skynvillunnar me\u00f0 annarri m\u00e6lingara\u00f0fer\u00f0 \u00fear sem \u00e1ttin \u00e1 \u00e1reitinu var metin. Ni\u00f0urst\u00f6\u00f0ur beggja ranns\u00f3knanna s\u00fdna a\u00f0 mismunandi t\u00edmamunur \u00e1 milli \u00e1reitanna tveggja me\u00f0 mismunandi styrk lei\u00f0ir til skynvillu \u00fear sem sta\u00f0setning \u00e1reitanna er metin ranglega: \u00feegar sterkt \u00e1reiti fylgdi \u00ed kj\u00f6lfar veiks \u00e1reitis skynju\u00f0u \u00fe\u00e1tttakendur hreyfingu ni\u00f0ur, en ef veikt \u00e1reiti kom fyrst og sterkt \u00ed kj\u00f6lfari\u00f0 skynju\u00f0u \u00fe\u00e1tttakendur hreyfingu upp \u00e1 vi\u00f0.<\/p>\n

Annar hluti doktorsritger\u00f0innar fjallar um Sound of Vision verkefni\u00f0 og skynskiptib\u00fana\u00f0inn sem var \u00fer\u00f3a\u00f0ur innan \u00feess fyrir blinda og sj\u00f3nskerta. \u00cd Sound of Vision er sj\u00f3nr\u00e6num uppl\u00fdsingum breytt \u00ed hlj\u00f3\u00f0 og snertiskynsskilabo\u00f0. Vi\u00f0 m\u00e1tum hversu vel \u00fe\u00e1tttakendum gekk a\u00f0 nota b\u00fana\u00f0inn. Fj\u00f3rt\u00e1n sj\u00e1andi \u00fe\u00e1tttakendur sem voru me\u00f0 bundi\u00f0 fyrir augun voru \u00fej\u00e1lfa\u00f0ir \u00ed tv\u00e6r klukkustundir vi\u00f0 notkun b\u00fana\u00f0arins. Einnig voru 6 blindir \u00fe\u00e1ttakendur \u00fej\u00e1lfa\u00f0ir \u00ed 8 klukkustundir hver \u00e1 b\u00fana\u00f0inum. \u00de\u00e1tttakendur \u00e1ttu a\u00f0 finna lei\u00f0 \u00ed gegnum sta\u00f0la\u00f0 umhverfi \u00fear sem \u00fdmiss konar hlutir voru \u00ed veginum. Frammista\u00f0an var metin \u00e1 kerfisbundinn h\u00e1tt (hversu oft \u00fe\u00e1tttakendur r\u00e1kust \u00e1 fyrirst\u00f6\u00f0u, hversu flj\u00f3tir \u00feeir voru a\u00f0 kl\u00e1ra verkefni\u00f0 og hversu vel \u00feeir fundu \u00e1reitin). Vi\u00f0 b\u00e1rum frammist\u00f6\u00f0una me\u00f0 SOV t\u00e6kinu saman vi\u00f0 frammist\u00f6\u00f0u me\u00f0 hv\u00edta stafnum. Ni\u00f0urst\u00f6\u00f0urnar s\u00fdndu a\u00f0 \u00fe\u00e1tttakendur l\u00e6r\u00f0u a\u00f0 nota SOV b\u00fana\u00f0inn hratt og \u00f6rugglega, sem leiddi til f\u00e6rri \u00e1rekstra og betri vitundar um fyrirst\u00f6\u00f0ur.<\/p>\n

Samanlagt s\u00fdna ni\u00f0urst\u00f6\u00f0urnar \u00ed \u00feessari ritger\u00f0 a\u00f0 h\u00e6gt er a\u00f0 \u00fer\u00f3a skynskiptib\u00fana\u00f0 fyrir blinda og sj\u00f3nskerta. Einnig ver\u00f0ur h\u00e6gt a\u00f0 nota ranns\u00f3knirnar \u00e1 snertiskyni vi\u00f0 frekari \u00fer\u00f3un \u00e1 b\u00fana\u00f0i sem nota\u00f0ur er til \u00feess a\u00f0 koma uppl\u00fdsingum til \u00fe\u00e1tttakenda \u00ed gegnum snertiskyn (t.d. \u00ed skynskiptib\u00fana\u00f0i), og veita frekari uppl\u00fdsingar um e\u00f0li snertiskyns.<\/p>\n

Abstract<\/strong><\/p>\n

Vibrotactile displays can compensate for the loss of sensory function of people with permanent or temporary deficiencies in vision, hearing, or balance, and augment the immersive experience in virtual environments. One key consideration when designing tactile displays is determining the minimal possible spacing between tactile actuators (tactors), by empirically assessing vibrotactile spatial acuity. We therefore assessed relative discrimination accuracy in the lower thoracic region by, comparing relative discrimination accuracy for three different tactor types. The results indicate that tactor characteristics significantly affect spatial acuity measurements, highlighting that the results of vibrotactile spatial acuity measurements may only apply to the specific tactors tested.<\/p>\n

Furthermore, the study of haptic illusions allows valuable insights into the neuro-cognitive processes underlying the perception of touch. They are also relevant for practical applications, since spatio-temporal illusions can be exploited to increase the perceived resolution of tactile displays. We conducted two experiments to verify a new spatio-temporal haptic illusion that involves an error of localization.<\/p>\n

Another part of the thesis is dedicated to the design, implementation and evaluation of multimodal sensory substitution devices (SSDs) for the visually impaired. We evaluated the efficiency and usability of a new audio-haptic SSD, as well as its auditory algorithm. Six blind subjects were trained for eight hours with the complete SSD. In both experiments, subjects were asked to navigate through a set of standardized scenes while their performance was systematically assessed. The results show rapid and substantial learning with the new SSD, with less collisions and higher obstacle awareness.<\/p>\n

Um doktorsefni\u00f0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/strong><\/p>\n

Rebekka Hoffmann er f\u00e6dd \u00e1ri\u00f0 1988 og lauk grunnh\u00e1sk\u00f3lagr\u00e1\u00f0u \u00ed s\u00e1lfr\u00e6\u00f0i fr\u00e1 Humboldt-h\u00e1sk\u00f3lanum \u00ed Berl\u00edn \u00e1ri\u00f0 2015. H\u00fan innrita\u00f0ist \u00e1ri s\u00ed\u00f0ar \u00ed doktorsn\u00e1m vi\u00f0 S\u00e1lfr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1273,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2019-01-18T13:00:00+00:00","_phd_date_end":"2019-01-18T16:00:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0asalur H\u00e1sk\u00f3la \u00cdslands","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Snerti- og titringsskynjun og notkun \u00feeirra \u00ed skynskiptib\u00fana\u00f0i fyrir blinda og sj\u00f3nskerta. Experiments on haptic perception in relation to sensory substitution for the blind","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_salfraedi_rebekka_hoffman","_phd_source_node_id":"314231","_phd_source_type":"vidburdir","_phd_member_id":257,"footnotes":""},"phd_school":[60,75],"phd_discipline":[76],"class_list":["post-6020","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-heilbrigdisvisindasvid","phd_school-salfraedideild","phd_discipline-phd-i-salfraedi"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6020","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6020\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/1273"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6020"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6020"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6020"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}