Limits...
The influence of vision on sound localization abilities in both the horizontal and vertical planes.

Tabry V, Zatorre RJ, Voss P - Front Psychol (2013)

Bottom Line: To address this unknown, we compared the sound localization ability of eight sighted individuals with and without a blindfold in a hemi-anechoic chamber.Results show that all three factors significantly interact with one another with regards to the average absolute deviation error.Moreover, blindfolding was found to increase the tendency to undershoot more eccentric spatial positions for head-pointing, but not hand-pointing.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Montreal, QC, Canada ; International Laboratory for Brain, Music and Sound Research (BRAMS) Montreal, QC, Canada.

ABSTRACT
Numerous recent reports have suggested that individuals deprived of vision are able to develop heightened auditory spatial abilities. However, most such studies have compared the blind to blindfolded sighted individuals, a procedure that might introduce a strong performance bias. Indeed, while blind individuals have had their whole lives to adapt to this condition, sighted individuals might be put at a severe disadvantage when having to localize sounds without visual input. To address this unknown, we compared the sound localization ability of eight sighted individuals with and without a blindfold in a hemi-anechoic chamber. Sound stimuli were broadband noise delivered via two speaker arrays: a horizontal array with 25 loudspeakers (ranging from -90° to +90°; 7.5°) and a vertical array with 16 loudspeakers (ranging from -45° to +67.5°). A factorial design was used, where we compared two vision conditions (blindfold vs. non-blindfold), two sound planes (horizontal vs. vertical) and two pointing methods (hand vs. head). Results show that all three factors significantly interact with one another with regards to the average absolute deviation error. Although blindfolding significantly affected all conditions, it did more so for head-pointing in the horizontal plane. Moreover, blindfolding was found to increase the tendency to undershoot more eccentric spatial positions for head-pointing, but not hand-pointing. Overall, these findings suggest that while proprioceptive cues appear to be sufficient for accurate hand pointing in the absence of visual feedback, head pointing relies more heavily on visual cues in order to provide a precise response. It also strongly argues against the use of head pointing methodologies with blindfolded sighted individuals, particularly in the horizontal plane, as it likely introduces a bias when comparing them to blind individuals.

No MeSH data available.


Related in: MedlinePlus

Signed error plots. Illustrated here are the signed error plots for each condition as a function of target location. Overlaid on top of the plots are first-order regression curves that were fitted to the signed error plots, for which the slopes can be taken as an index of the tendency to undershoot or overshoot target locations. In general, signed error tended to increase (undershoot) as a function of target eccentricity, and was further increased by blindfolding. However, this effect was primarily driven by the head pointing trials, as blindfolding did not have a significant effect on hand pointing. There was also a significant effect of auditory spatial plane, where the slope was greater for trials on the vertical plane.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3860057&req=5

Figure 3: Signed error plots. Illustrated here are the signed error plots for each condition as a function of target location. Overlaid on top of the plots are first-order regression curves that were fitted to the signed error plots, for which the slopes can be taken as an index of the tendency to undershoot or overshoot target locations. In general, signed error tended to increase (undershoot) as a function of target eccentricity, and was further increased by blindfolding. However, this effect was primarily driven by the head pointing trials, as blindfolding did not have a significant effect on hand pointing. There was also a significant effect of auditory spatial plane, where the slope was greater for trials on the vertical plane.

Mentions: Figure 3 shows the mean signed error in all conditions. A repeated measures 2 × 2 × 2 was performed on the signed error in the same manner as it was for the unsigned error. No main effects or interactions were found to be significant (all p > 0.146).


The influence of vision on sound localization abilities in both the horizontal and vertical planes.

Tabry V, Zatorre RJ, Voss P - Front Psychol (2013)

Signed error plots. Illustrated here are the signed error plots for each condition as a function of target location. Overlaid on top of the plots are first-order regression curves that were fitted to the signed error plots, for which the slopes can be taken as an index of the tendency to undershoot or overshoot target locations. In general, signed error tended to increase (undershoot) as a function of target eccentricity, and was further increased by blindfolding. However, this effect was primarily driven by the head pointing trials, as blindfolding did not have a significant effect on hand pointing. There was also a significant effect of auditory spatial plane, where the slope was greater for trials on the vertical plane.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3860057&req=5

Figure 3: Signed error plots. Illustrated here are the signed error plots for each condition as a function of target location. Overlaid on top of the plots are first-order regression curves that were fitted to the signed error plots, for which the slopes can be taken as an index of the tendency to undershoot or overshoot target locations. In general, signed error tended to increase (undershoot) as a function of target eccentricity, and was further increased by blindfolding. However, this effect was primarily driven by the head pointing trials, as blindfolding did not have a significant effect on hand pointing. There was also a significant effect of auditory spatial plane, where the slope was greater for trials on the vertical plane.
Mentions: Figure 3 shows the mean signed error in all conditions. A repeated measures 2 × 2 × 2 was performed on the signed error in the same manner as it was for the unsigned error. No main effects or interactions were found to be significant (all p > 0.146).

Bottom Line: To address this unknown, we compared the sound localization ability of eight sighted individuals with and without a blindfold in a hemi-anechoic chamber.Results show that all three factors significantly interact with one another with regards to the average absolute deviation error.Moreover, blindfolding was found to increase the tendency to undershoot more eccentric spatial positions for head-pointing, but not hand-pointing.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Montreal, QC, Canada ; International Laboratory for Brain, Music and Sound Research (BRAMS) Montreal, QC, Canada.

ABSTRACT
Numerous recent reports have suggested that individuals deprived of vision are able to develop heightened auditory spatial abilities. However, most such studies have compared the blind to blindfolded sighted individuals, a procedure that might introduce a strong performance bias. Indeed, while blind individuals have had their whole lives to adapt to this condition, sighted individuals might be put at a severe disadvantage when having to localize sounds without visual input. To address this unknown, we compared the sound localization ability of eight sighted individuals with and without a blindfold in a hemi-anechoic chamber. Sound stimuli were broadband noise delivered via two speaker arrays: a horizontal array with 25 loudspeakers (ranging from -90° to +90°; 7.5°) and a vertical array with 16 loudspeakers (ranging from -45° to +67.5°). A factorial design was used, where we compared two vision conditions (blindfold vs. non-blindfold), two sound planes (horizontal vs. vertical) and two pointing methods (hand vs. head). Results show that all three factors significantly interact with one another with regards to the average absolute deviation error. Although blindfolding significantly affected all conditions, it did more so for head-pointing in the horizontal plane. Moreover, blindfolding was found to increase the tendency to undershoot more eccentric spatial positions for head-pointing, but not hand-pointing. Overall, these findings suggest that while proprioceptive cues appear to be sufficient for accurate hand pointing in the absence of visual feedback, head pointing relies more heavily on visual cues in order to provide a precise response. It also strongly argues against the use of head pointing methodologies with blindfolded sighted individuals, particularly in the horizontal plane, as it likely introduces a bias when comparing them to blind individuals.

No MeSH data available.


Related in: MedlinePlus