Visual Search Behavior in Individuals With Retinitis Pigmentosa During Level Walking and Obstacle Crossing

Timmis, Matthew A.; Allsop, Jonathan; Baranian, Mohammad; Baker, James H.; Basevitch, Itay; Latham, Keziah; Pardhan, Shahina; Paridon, Kjell N. van

doi:10.1167/iovs.17-21573

Cited by 11 publications

(11 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“… 40 , 41 Recent work shows that people with retinitis pigmentosa spend an equal amount of time fixating an obstacle in this situation, but they spend less time looking past the obstacle to the path ahead, and a greater amount of time fixating the ground before the obstacle compared with normally sighted controls. 42 When stepping over an obstacle, normally sighted older adults shift gaze to the obstacle earlier and for longer than young adults. 43 , 44 However, spending more time fixating an obstacle when having to avoid it, rather than when having to step over it, is not necessarily an ideal strategy.…”

Section: Discussionmentioning

confidence: 99%

Glaucoma-Related Differences in Gaze Behavior When Negotiating Obstacles

Lajoie

Miller

Strath

et al. 2018

Trans. Vis. Sci. Tech.

View full text Add to dashboard Cite

PurposeSafe navigation requires avoiding objects. Visual field loss may affect how one visually samples the environment, and may thus contribute to bumping into objects and falls. We tested the hypothesis that gaze strategies and the number of collisions differ between people with glaucoma and normally sighted controls when navigating around obstacles, particularly under multitasking situations.MethodsTwenty persons with moderate–severe glaucoma and 20 normally sighted controls walked around a series of irregularly spaced vertical obstacles under the following three conditions: walking with obstacles only, walking and counting backward to simulate a conversation, and walking while performing a concurrent visual search task to simulate locating a landmark. We quantified gaze patterns and the number of obstacle contacts.ResultsCompared with controls, people with glaucoma directed gaze closer to their current position (P < 0.05). They also directed a larger proportion of fixations (in terms of number and duration) to obstacles (P < 0.05). Despite this finding, considerably more people with glaucoma contacted an obstacle (P < 0.05). Multitasking led to changes in gaze behavior in both groups, and this was accompanied by a large increase in obstacle contacts among those with glaucoma (P < 0.05).ConclusionsGlaucoma alters gaze patterns when negotiating a series of obstacles and increases the likelihood of collisions. Multitasking in this situation exacerbates these changes.Translational RelevanceUnderstanding glaucoma-related changes in gaze behavior during walking in cluttered environments may provide critical insight for orientation and mobility specialists and guide the design of gaze training interventions to improve mobility.

show abstract

Section: Discussionmentioning

confidence: 99%

Glaucoma-Related Differences in Gaze Behavior When Negotiating Obstacles

Lajoie

Miller

Strath

et al. 2018

Trans. Vis. Sci. Tech.

View full text Add to dashboard Cite

show abstract

“…Gaze behaviour was collected at 30 Hz using an SMI iView ETG head mounted mobile eye tracker (version 1.0; SensoMotoric Instruments, Teltow, Germany). Additional information about the eye-tracker system has been published previously 66 . The lenses (used in the blurred group only) were attached to the front, outside of the eye tracker such that it would not influence the eye tracker’s ability to track eye movements.…”

Section: Methodsmentioning

confidence: 99%

“…Each trial was tracked from the frame that the LED above the start pad started flashing (i.e., start of the trial) up to the frame where the hand made contact with the end pad (i.e., end of the trial). The areas of interest were adopted from a previous obstacle crossing study 66 . The following areas of interest were used (see also Fig.…”

Section: Methodsmentioning

confidence: 99%

The effects of temporal pressure on obstacle negotiation and gaze behaviour in young adults with simulated vision loss

Zult

Allsop

Timmis

et al. 2019

Sci Rep

Self Cite

View full text Add to dashboard Cite

Individuals with vision loss adapt their locomotion and gaze behaviour to safely negotiate objects in temporally unconstrained situations. However, everyday activities are often performed under timepressure. We investigated the effects of blur on anxiety, movement kinematics and gaze behaviour during the negotiation of a floor-based obstacle under three amounts of pressure: 1) no-pressure; 2) tonal-pressure: an intermittent tone was played at a constant frequency; 3) tonal + time pressure: the intermittent tone increased in frequency and participants had to walk 20% faster to reach the end of the lab. Irrespective of the amount of pressure, the blurred vs. normal vision group reported 32% more anxiety, lifted the lead foot 43% higher and 10% slower over the obstacle, and looked 6% longer and 6% more frequently ahead of the obstacle. In the tonal + time pressure vs. no-pressure condition, both groups were more anxious, showed adaptations in movement kinematics related to walking faster, and adopted a 'checking strategy' by shortening their fixation durations at the obstacle. These results show that irrespective of temporal pressure, the blurred vision group remained more cautious as to how the lead foot negotiated the obstacle, in order to reduce the chance of tripping during crossing.

show abstract

“…They found that the gaze fixation of participants with low vision was frequently located in a transitional region between various surfaces in addition to an actual surface. Similarly, Timmis et al (2017) compared the gazing behavior of people with low vision and that of fully sighted people navigating an indoor walkway with obstacles on the surface. They reported that people with low vision demonstrated a more active visual search pattern, looking at more areas on the ground than fully sighted people.…”

Section: Previous Studiesmentioning

confidence: 99%

Gazing behavior exhibited by people with low vision while navigating streets

Matsuda

Kawauchi²,

Motooka

2020

Journal of Asian Architecture and Building Engineering

View full text Add to dashboard Cite

"Low vision" is defined as uncorrectable vision loss that interferes with daily activities. The gazing behavior exhibited by people with low vision as they walk is particularly important because it illustrates how they utilize information in various environments. In this study, eight participants with low vision and eight fully sighted participants were asked to navigate a roadway and a sidewalk wearing a mobile eye-tracking device. Their gazing behavior and walking behavior were recorded and analyzed. As a result, on the roadway, participants with low vision walked while fixing their gazes mainly on the road surface and white traffic lines around 10 meters ahead, as well as on the buildings around 39 meters ahead. On the sidewalk, on the other hand, they walked while fixing their gaze on mainly the road surface and tactile paving seven to eight meters ahead, as well as on the buildings around 24 meters ahead. These findings suggest that people with low vision use not only nearby objects but also distant objects as visual cues. In addition, the importance of using continuous road surface markers, such as white traffic lines and tactile paving, to enable people with low vision to walk outdoors safely is suggested.

show abstract

Visual Search Behavior in Individuals With Retinitis Pigmentosa During Level Walking and Obstacle Crossing

Cited by 11 publications

References 33 publications

Glaucoma-Related Differences in Gaze Behavior When Negotiating Obstacles

Glaucoma-Related Differences in Gaze Behavior When Negotiating Obstacles

The effects of temporal pressure on obstacle negotiation and gaze behaviour in young adults with simulated vision loss

Gazing behavior exhibited by people with low vision while navigating streets

Contact Info

Product

Resources

About