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Visual and Non-Visual Navigation in Blind Patients with a Retinal Prosthesis.

Garcia S, Petrini K, Rubin GS, Da Cruz L, Nardini M - PLoS ONE (2015)

Bottom Line: Participants completed a path reproduction and a triangle completion navigation task, using either an indirect visual landmark and non-visual self-motion cues or non-visual self-motion cues only.In both tasks, control participants showed better precision when navigating with reduced vision, compared to without vision.Additionally, all patients showed greater precision than controls in both tasks when navigating without vision.

View Article: PubMed Central - PubMed

Affiliation: Institute of Ophthalmology, University College London (UCL), London, United Kingdom.

ABSTRACT
Human adults with normal vision can combine visual landmark and non-visual self-motion cues to improve their navigational precision. Here we asked whether blind individuals treated with a retinal prosthesis could also benefit from using the resultant new visual signal together with non-visual information when navigating. Four patients (blind for 15-52 years) implanted with the Argus II retinal prosthesis (Second Sight Medical Products Inc. Sylmar, CA), and five age-matched and six younger controls, participated. Participants completed a path reproduction and a triangle completion navigation task, using either an indirect visual landmark and non-visual self-motion cues or non-visual self-motion cues only. Control participants wore goggles that approximated the field of view and the resolution of the Argus II prosthesis. In both tasks, control participants showed better precision when navigating with reduced vision, compared to without vision. Patients, however, did not show similar improvements when navigating with the prosthesis in the path reproduction task, but two patients did show improvements in the triangle completion task. Additionally, all patients showed greater precision than controls in both tasks when navigating without vision. These results indicate that the Argus II retinal prosthesis may not provide sufficiently reliable visual information to improve the precision of patients on tasks, for which they have learnt to rely on non-visual senses.

No MeSH data available.


A & B: Schematic of path reproduction and triangle completion tasks. C: View of the landmark through the goggles worn by normally sighted participants. Participants were guided along the black path by the experimenter, and then: (i) For path reproduction, guided back to the start position and asked to reproduce the path as accurately as possible. (ii) For triangle completion, asked to return to the start position as accurately as possible.
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pone.0134369.g002: A & B: Schematic of path reproduction and triangle completion tasks. C: View of the landmark through the goggles worn by normally sighted participants. Participants were guided along the black path by the experimenter, and then: (i) For path reproduction, guided back to the start position and asked to reproduce the path as accurately as possible. (ii) For triangle completion, asked to return to the start position as accurately as possible.

Mentions: Participants were led to a start position and advised that the experimenter would guide them along a path which they would then be asked to reproduce as accurately as possible. The path comprised of an initial 2.5m leg, a 75° rotation, and a final 2m leg. The landmark was positioned midway along the second leg. This meant that it could potentially provide information about the correct initial heading, the distance after which to turn, and the correct turning angle, (see Fig 2A).


Visual and Non-Visual Navigation in Blind Patients with a Retinal Prosthesis.

Garcia S, Petrini K, Rubin GS, Da Cruz L, Nardini M - PLoS ONE (2015)

A & B: Schematic of path reproduction and triangle completion tasks. C: View of the landmark through the goggles worn by normally sighted participants. Participants were guided along the black path by the experimenter, and then: (i) For path reproduction, guided back to the start position and asked to reproduce the path as accurately as possible. (ii) For triangle completion, asked to return to the start position as accurately as possible.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4520559&req=5

pone.0134369.g002: A & B: Schematic of path reproduction and triangle completion tasks. C: View of the landmark through the goggles worn by normally sighted participants. Participants were guided along the black path by the experimenter, and then: (i) For path reproduction, guided back to the start position and asked to reproduce the path as accurately as possible. (ii) For triangle completion, asked to return to the start position as accurately as possible.
Mentions: Participants were led to a start position and advised that the experimenter would guide them along a path which they would then be asked to reproduce as accurately as possible. The path comprised of an initial 2.5m leg, a 75° rotation, and a final 2m leg. The landmark was positioned midway along the second leg. This meant that it could potentially provide information about the correct initial heading, the distance after which to turn, and the correct turning angle, (see Fig 2A).

Bottom Line: Participants completed a path reproduction and a triangle completion navigation task, using either an indirect visual landmark and non-visual self-motion cues or non-visual self-motion cues only.In both tasks, control participants showed better precision when navigating with reduced vision, compared to without vision.Additionally, all patients showed greater precision than controls in both tasks when navigating without vision.

View Article: PubMed Central - PubMed

Affiliation: Institute of Ophthalmology, University College London (UCL), London, United Kingdom.

ABSTRACT
Human adults with normal vision can combine visual landmark and non-visual self-motion cues to improve their navigational precision. Here we asked whether blind individuals treated with a retinal prosthesis could also benefit from using the resultant new visual signal together with non-visual information when navigating. Four patients (blind for 15-52 years) implanted with the Argus II retinal prosthesis (Second Sight Medical Products Inc. Sylmar, CA), and five age-matched and six younger controls, participated. Participants completed a path reproduction and a triangle completion navigation task, using either an indirect visual landmark and non-visual self-motion cues or non-visual self-motion cues only. Control participants wore goggles that approximated the field of view and the resolution of the Argus II prosthesis. In both tasks, control participants showed better precision when navigating with reduced vision, compared to without vision. Patients, however, did not show similar improvements when navigating with the prosthesis in the path reproduction task, but two patients did show improvements in the triangle completion task. Additionally, all patients showed greater precision than controls in both tasks when navigating without vision. These results indicate that the Argus II retinal prosthesis may not provide sufficiently reliable visual information to improve the precision of patients on tasks, for which they have learnt to rely on non-visual senses.

No MeSH data available.