Processes Involved in Oculomotor Adaptation to Eccentric Reading

Fornos, Ange ́lica Pe ́rez; Sommerhalder, J.; Rappaz, Benjamin; Pelizzone, M.; Safran, Avinoam B.

doi:10.1167/iovs.05-0973

Cited by 17 publications

(5 citation statements)

References 30 publications

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“…Subjects adapted reading behavior to an artificial central scotoma by settling into a preferred reading locus after 5--10 sessions of 15--40 min duration each, with concomitant improvements in accuracy (Varsori et al 2004). Interestingly, subjects forced to read within an eccentric window in the inferior field showed a biphasic pattern of change (Fornos et al 2006). Over the first 5--10 sessions of about 30 min duration each, there was a rapid reduction in the number of vertical saccades, which represented ineffective attempts to foveate the reading zone.…”

Section: Discussionmentioning

confidence: 99%

Rapid Adaptation of Visual Search in Simulated Hemianopia

Simpson¹,

Abegg²,

Barton³

2010

Cerebral Cortex

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Patients with homonymous hemianopia have altered visual search patterns, but it is unclear how rapidly this develops and whether it reflects a strategic adaptation to altered perception or plastic changes to tissue damage. To study the temporal dynamics of adaptation alone, we used a gaze-contingent display to simulate left or right hemianopia in 10 healthy individuals as they performed 25 visual search trials. Visual search was slower and less accurate in hemianopic than in full-field viewing. With full-field viewing, there were improvements in search speed, fixation density, and number of fixations over the first 9 trials, then stable performance. With hemianopic viewing, there was a rapid shift of fixation into the blind field over the first 5-7 trials, followed by continuing gradual improvements in completion time, number of fixations, and fixation density over all 25 trials. We conclude that in the first minutes after onset of hemianopia, there is a biphasic pattern of adaptation to altered perception: an early rapid qualitative change that shifts visual search into the blind side, followed by more gradual gains in the efficiency of using this new strategy, a pattern that has parallels in other studies of motor learning.

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Section: Discussionmentioning

confidence: 99%

Rapid Adaptation of Visual Search in Simulated Hemianopia

Simpson¹,

Abegg²,

Barton³

2010

Cerebral Cortex

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“…First, masking larger parts of the visual field does not provide control over the precise retinal location chosen by the participant and therefore is of limited use for studying the underlying oculomotor processes. Similar to our approach, Fornos, Sommerhalder, Rappaz, Pelizzone, and Safran (2006) used a large rectangular viewing window that was shifted with respect to current fixation, but these authors did not vary the location of the viewing window. Second, standard gaze-contingent displays consist of rectangular masks with sharp borders, features that are unlikely to be seen with natural scotomas.…”

Section: Methodological Considerationsmentioning

confidence: 99%

Adaptive strategies for reading with a forced retinal location

Lingnau¹,

Schwarzbach²,

Vorberg³

2008

Journal of Vision

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Forcing normal-sighted participants to use a distinct parafoveal retinal location for reading, we studied which part of the visual field is best suited to take over functions of the fovea during early stages of macular degeneration (MD). A region to the right of fixation lead to best reading performance and most natural gaze behavior, whereas reading performance was severely impaired when a region to the left or below fixation had to be used. An analysis of the underlying oculomotor behavior revealed that practice effects were accompanied by a larger number of saccades in text direction and decreased fixation durations, whereas no adjustment of saccade amplitudes was observed. We provide an explanation for the observed performance differences at different retinal locations based on the interplay of attention and eye movements. Our findings have important implications for the development of training methods for MD patients targeted at reading, suggesting that it would be beneficial for MD patients to use a region to the right of their central scotoma.

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“…9 Although such PRLs have been shown to develop naturally in many cases, 10 over the past decade, there were several studies focused on eccentric fixation training and low vision rehabilitation strategy to assist patients with disciform scar. [11][12][13][14] The most common training techniques used are reading exercises with optical low vision aids or on closed-circuit television (CCTV), the patient is asked to practise scotoma placement with eye movement control. These techniques require extensive individual patient training and a considerable investment of professional training time for optimum results.…”

Section: Discussionmentioning

confidence: 99%