Search results for "Saccade"
showing 8 items of 28 documents
Subtle Increases in Interletter Spacing Facilitate the Encoding of Words during Normal Reading
2012
BackgroundSeveral recent studies have revealed that words presented with a small increase in interletter spacing are identified faster than words presented with the default interletter spacing (i.e., w a t e r faster than water). Modeling work has shown that this advantage occurs at an early encoding level. Given the implications of this finding for the ease of reading in the new digital era, here we examined whether the beneficial effect of small increases in interletter spacing can be generalized to a normal reading situation.MethodologyWe conducted an experiment in which the participant's eyes were monitored when reading sentences varying in interletter spacing: i) sentences were present…
A dynamic adjustment model of saccade lengths in reading for word-spaced orthographies : evidence from simulations and invisible boundary experiments
2021
Contemporary models of eye movement control in reading assume a discrete target word selection process preceding saccade length computation, while the selection itself is assumed to be driven by word identification processes. However, a potentially more parsimonious, dynamic adjustment view allows both next word length and its content (e.g. orthographic) to modulate saccade length in a continuous manner. Based on a recently proposed center-based saccade length account (a new regression model of forward saccade length is introduced and validated in a simulation study. Further, additional simulations and gaze-contingent invisible boundary experiments were used to study the cognitive mechanism…
Acu kustības pabeigtu un nepabeigtu objektu kontūru izsekošanā
2016
Maģistra darbs ir uzrakstīts latviešu valodā uz 39 lapaspusēm. Tas satur 26 attēlus, 9 tabulas, 1 pielikums, 20 atsauces uz literatūras avotiem. Darba mērķis: Novērtēt acu kustības, izsekojot pabeigtu un nepabeigtu figūru kontūras. Metode: Acu kustības tika noteiktas, izmantojot acu kustību iekārtu IViewX RED500. Tika apskatīti fiksāciju un sakāžu raksturlielumi un acu kustību precizitāte. Subjekti: Pētījumā piedalījās 6 dalībnieki. Rezultāti: Izsekojot pabeigtu, nepabeigtu un izzūdošu figūru kontūras, nenovēroja būtiskas atšķirības sakāžu skaitā, vidējā amplitūdā un ātrumā, bet latence bija būtiski īsāka izzūdošas figūras aplūkošanas laikā. Pabeigtu un izzūdošu figūru kontūras izsekošana i…
Developmental dyslexia: Visual abnormalities during ocular rotation
2005
[u]Purpose[/u]: Most of the studies dealing with visual perception disabilities in children suffering from developmental dyslexia have been done in orthophoric position. The objective of the present study is to explore the visual perception during eye movements. [u]Methods[/u]: Sixty male patients (11.8 ± 1.8 years) were examined by neuropsychologists to evaluate reading difficulties. Visual perception during ocular rotation was assessed with a Clement Clarke synoptophore with G3–G4 slides, in primary gaze, then laterally at 20, 30 and 40° in dim light. [u]Results[/u]: Three main abnormalities were found. • Isolated perception abnormalities with intermittent shading of the image, central, p…
Simple Configuration Effects on Eye Movements in Horizontal Scanning Tasks
2015
When reading text, observers alternate periods of stable gaze (fixations) and shifts of gaze (saccades). An important debate in the literature concerns the processes that drive the control of these eye movements. Past studies using strings of letters rather than meaningful text ('z-reading') suggest that eye movement control during reading is, to a large extent, controlled by low-level image properties. These studies, however, have failed to take into account perceptual grouping processes that could drive these low-level effects. We here study the role of various grouping factors in horizontal scanning eye movements, and compare these to reading meaningful text. The results show that sequen…
Processing Information During Regressions: An Application of the Reverse Boundary-Change Paradigm.
2018
Although 10-15% of eye-movements during reading are regressions, we still know little about the information that is processed during regressive episodes. Here, we report an eye-movement study that uses what we call the "reverse boundary change technique" to examine the processing of lexical-semantic information during regressions, and to establish the role of this information during recovery from processing difficulty. In the critical condition of the experiment, an initially implausible sentence (e.g. "There was an old house that John had ridden when he was a boy.") was rendered plausible by changing a context word ("house") to a lexical neighbour ("horse") using a gaze-contingent display …
Binocular, Accommodative and Oculomotor Alterations In Multiple Sclerosis: A Review
2020
Multiple sclerosis (MS) is an acquired demyelinating and inflammatory neurodegenerative disease affecting the central nervous system (CNS). Clinical and subclinical ocular disturbances occur in almost all patients with MS. The objective of this narrative review was to collect and summarize the available scientific information on oculomotor, accommodative and binocular alterations that have been reported in MS. A systematic search strategy with the following descriptors was carried out: multiple sclerosis, ocular motility disorders, internuclear ophthalmoplegia, nystagmus, vergences, fixation, pupil reflex, accommodation and stereopsis. According to the search, some oculomotor alterations w…
Ocular motor biomarkers in Niemann-Pick disease type C: A prospective cross-sectional multicontinental study in 72 patients
2020
AbstractNiemann-Pick type C (NPC) is a rare lysosomal storage disorder with ocular motor involvement. In a multicontinental, cross-sectional study we characterized ocular motor function in 72 genetically proven patients from twelve countries by means of video-oculography. Interlinking with disease severity, we also searched for ocular motor biomarkers. Our study protocol comprised reflexive and self-paced saccades, smooth pursuit, and gaze-holding in horizontal and vertical planes. Data were compared with those of 158 healthy controls. The Modified Disability Rating Scale, Scale for Assessment and Rating of Ataxia, Spinocerebellar Ataxia Functional Index for neurological status, and Montrea…