Saccade control without a fovea

Whittaker, Stephen G.; Cummings, Roger W.; Swieson, Lisa R.

doi:10.1016/0042-6989(91)90173-3

Cited by 102 publications

(84 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The link between the deployment of attention to and subsequent foveation of a visual target appears to be an automatic process, which is so dominant that it takes AMD patients several months to adapt the oculomotor system to eccentric fixating (Crossland, Culham, Kabanarou, & Rubin, 2005) and may not be complete even years after the onset of the disease (Crossland, Culham, & Rubin, 2004;Tarita-Nistor, González, Markowitz, & Steinbach, 2008;White & Bedell, 1990;Whittaker, Cummings, & Swieson, 1991). The attentional resources needed to suppress foveation and explore search displays with peripheral vision are thus not available for contextual cueing.…”

Section: Discussionmentioning

confidence: 96%

Contextual cueing impairment in patients with age-related macular degeneration

et al. 2013

View full text Add to dashboard Cite

Visual attention can be guided by past experience of regularities in our visual environment. In the contextual cueing paradigm, incidental learning of repeated distractor configurations speeds up search times compared to random search arrays. Concomitantly, fewer fixations and more direct scan paths indicate more efficient visual exploration in repeated search arrays. In previous work, we found that simulating a central scotoma in healthy observers eliminated this search facilitation. Here, we investigated contextual cueing in patients with age-related macular degeneration (AMD) who suffer from impaired foveal vision. AMD patients performed visual search using only their more severely impaired eye (n = 13) as well as under binocular viewing (n = 16). Normal-sighted controls developed a significant contextual cueing effect. In comparison, patients showed only a small nonsignificant advantage for repeated displays when searching with their worse eye. When searching binocularly, they profited from contextual cues, but still less than controls. Number of fixations and scan pattern ratios showed a comparable pattern as search times. Moreover, contextual cueing was significantly correlated with acuity in monocular search. Thus, foveal vision loss may lead to impaired guidance of attention by contextual memory cues.

show abstract

Section: Discussionmentioning

confidence: 96%

Contextual cueing impairment in patients with age-related macular degeneration

et al. 2013

View full text Add to dashboard Cite

show abstract

“…The ability of the PRL to direct eye movements, whether it be saccadic ability (measured by the number and characteristics of saccades) or fixation stability, are far more closely correlated with reading speed and correct reading rate than either visual acuity or the presence of a scotoma (Schuchard 2005;Petre et al 2000;Sunness et al 1996;Cummings et al 1985;Steinman et al 1973;Whittaker et al 1991). It is perhaps surprising that there is no correlation between scotoma size and fixation stability, as fixation is known to become less precise as eccentricity increases, and a larger scotoma will lead to a more eccentric PRL being used.…”

Section: Discussionmentioning

confidence: 99%

Low-Vision Rehabilitation by Means of MP-1 Biofeedback Examination in Patients with Different Macular Diseases: A Pilot Study

Salvatore

Cavarretta

2009

Appl Psychophysiol Biofeedback

View full text Add to dashboard Cite

Macular disease is one of the main causes of visual impairment. We studied the efficacy of low-vision rehabilitation by means of MP-1 biofeedback examination in patients with different macular disease. Five patients were enrolled (3 female and 2 male, mean age 53.8 years) and a total of 9 eyes was examined: 2 eyes with vitelliform dystrophy, 1 with a post-traumatic macular scar, 2 with Stargardt disease, 2 with myopic macular degeneration, 2 with cone dystrophy. All the patients underwent the following tests: visual acuity, reading speed, fixation test, MP-1 microperimetry. Low-vision rehabilitation, which lasted 10 weeks, consisted of 10 training sessions of 10 min for each eye, performed once a week using the MP-1 biofeedback examination. Statistical analysis was performed using Student's t-test. p values less than 0.05 were considered statistically significant. After training all patients displayed an improvement in visual acuity, fixation behaviour, retinal sensitivity and reading speed. Fixation behaviour within the 2 degrees diameter circle improved and was statistically significant for reading speed (p = 0.01). Reading speed improved from a mean value of 64.3 to 92 words/min. Our results show that audio feedback can, by increasing attentional modulation, help the brain to fix the final preferred retinal locus. Audio feedback facilitates stimuli transmission between intraretinal neurons as well as between the retina and brain, which is where the highest level of stimuli processing occurs, thereby probably supporting a "remapping phenomenon".

show abstract

“…If the PRL becomes the new reference for eye movements, the absence of radial saccades towards the fovea should reduce crowding. Consistently with this hypothesis, several studies showed a re-referencing of eye movements towards the PRL in AMD patients (White and Bedell, 1990; Whittaker et al, 1991). Finally, Chung (2013) suggested that the cortical site for spontaneous reorganization might be localized within visual areas usually associated with crowding, i.e., V1 (Nandy and Tjan, 2012), V2 (Freeman and Simoncelli, 2011), V3 (Tyler and Likova, 2007; Bi et al, 2009) or V4 (Motter, 2006).…”

Section: Perceptual Learning In Amdmentioning

confidence: 62%

Rehabilitation Approaches in Macular Degeneration Patients

Maniglia

Cottereau

Soler

et al. 2016

Front. Syst. Neurosci.

View full text Add to dashboard Cite

Age related macular degeneration (AMD) is a visual disease that affects elderly population. It entails a progressive loss of central vision whose consequences are dramatic for the patient’s quality of life. Current rehabilitation programs are restricted to technical aids based on visual devices. They only temporarily improve specific visual functions such as reading skills. Considering the rapid increase of the aging population worldwide, it is crucial to intensify clinical research on AMD in order to develop simple and efficient methods that improve the patient’s visual performances in many different contexts. One very promising approach to face this challenge is based on perceptual learning (PL). Through intensive practice, PL can induce neural plasticity in sensory cortices and result in long-lasting enhancements for various perceptual tasks in both normal and visually impaired populations. A growing number of studies showed how appropriate PL protocols improve visual functions in visual disorders, namely amblyopia, presbyopia or myopia. In order to successfully apply these approaches to more severe conditions such as AMD, numerous challenges have to be overcome. Indeed, the overall elderly age of patients and the reduced cortical surface that is devoted to peripheral vision potentially limit neural plasticity in this population. In addition, ocular fixation becomes much less stable because patients have to rely on peripheral fixation spots outside the scotoma whose size keeps on evolving. The aim of this review article is to discuss the recent literature on this topic and to offer a unified approach for developing new rehabilitation programs of AMD using PL. We argue that with an appropriate experimental and training protocol that is adapted to each patient needs, PL can offer fascinating opportunities for the development of simple, non-expensive rehabilitation approaches a large spectrum of visual functions in AMD patients.

show abstract

Saccade control without a fovea

Cited by 102 publications

References 27 publications

Contextual cueing impairment in patients with age-related macular degeneration

Contextual cueing impairment in patients with age-related macular degeneration

Low-Vision Rehabilitation by Means of MP-1 Biofeedback Examination in Patients with Different Macular Diseases: A Pilot Study

Rehabilitation Approaches in Macular Degeneration Patients

Contact Info

Product

Resources

About