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Depth discrimination of constant angular size stimuli in action space: role of accommodation and convergence cues
In our daily life experience, the angular size of an object correlates with its distance from the observer, provided that the physical size of the object remains constant. In this work, we investigated depth perception in action space (i.e., beyond the arm reach), while keeping the angular size of t...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4584972/ https://www.ncbi.nlm.nih.gov/pubmed/26441608 http://dx.doi.org/10.3389/fnhum.2015.00511 |
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author | Naceri, Abdeldjallil Moscatelli, Alessandro Chellali, Ryad |
author_facet | Naceri, Abdeldjallil Moscatelli, Alessandro Chellali, Ryad |
author_sort | Naceri, Abdeldjallil |
collection | PubMed |
description | In our daily life experience, the angular size of an object correlates with its distance from the observer, provided that the physical size of the object remains constant. In this work, we investigated depth perception in action space (i.e., beyond the arm reach), while keeping the angular size of the target object constant. This was achieved by increasing the physical size of the target object as its distance to the observer increased. To the best of our knowledge, this is the first time that a similar protocol has been tested in action space, for distances to the observer ranging from 1.4–2.4 m. We replicated the task in virtual and real environments and we found that the performance was significantly different between the two environments. In the real environment, all participants perceived the depth of the target object precisely. Whereas, in virtual reality (VR) the responses were significantly less precise, although, still above chance level in 16 of the 20 observers. The difference in the discriminability of the stimuli was likely due to different contributions of the convergence and the accommodation cues in the two environments. The values of Weber fractions estimated in our study were compared to those reported in previous studies in peripersonal and action space. |
format | Online Article Text |
id | pubmed-4584972 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-45849722015-10-05 Depth discrimination of constant angular size stimuli in action space: role of accommodation and convergence cues Naceri, Abdeldjallil Moscatelli, Alessandro Chellali, Ryad Front Hum Neurosci Neuroscience In our daily life experience, the angular size of an object correlates with its distance from the observer, provided that the physical size of the object remains constant. In this work, we investigated depth perception in action space (i.e., beyond the arm reach), while keeping the angular size of the target object constant. This was achieved by increasing the physical size of the target object as its distance to the observer increased. To the best of our knowledge, this is the first time that a similar protocol has been tested in action space, for distances to the observer ranging from 1.4–2.4 m. We replicated the task in virtual and real environments and we found that the performance was significantly different between the two environments. In the real environment, all participants perceived the depth of the target object precisely. Whereas, in virtual reality (VR) the responses were significantly less precise, although, still above chance level in 16 of the 20 observers. The difference in the discriminability of the stimuli was likely due to different contributions of the convergence and the accommodation cues in the two environments. The values of Weber fractions estimated in our study were compared to those reported in previous studies in peripersonal and action space. Frontiers Media S.A. 2015-09-16 /pmc/articles/PMC4584972/ /pubmed/26441608 http://dx.doi.org/10.3389/fnhum.2015.00511 Text en Copyright © 2015 Naceri, Moscatelli and Chellali. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution and reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Neuroscience Naceri, Abdeldjallil Moscatelli, Alessandro Chellali, Ryad Depth discrimination of constant angular size stimuli in action space: role of accommodation and convergence cues |
title | Depth discrimination of constant angular size stimuli in action space: role of accommodation and convergence cues |
title_full | Depth discrimination of constant angular size stimuli in action space: role of accommodation and convergence cues |
title_fullStr | Depth discrimination of constant angular size stimuli in action space: role of accommodation and convergence cues |
title_full_unstemmed | Depth discrimination of constant angular size stimuli in action space: role of accommodation and convergence cues |
title_short | Depth discrimination of constant angular size stimuli in action space: role of accommodation and convergence cues |
title_sort | depth discrimination of constant angular size stimuli in action space: role of accommodation and convergence cues |
topic | Neuroscience |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4584972/ https://www.ncbi.nlm.nih.gov/pubmed/26441608 http://dx.doi.org/10.3389/fnhum.2015.00511 |
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