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Seeing 'where' through the ears: effects of learning-by-doing and long-term sensory deprivation on localization based on image-to-sound substitution.

Proulx MJ, Stoerig P, Ludowig E, Knoll I - PLoS ONE (2008)

Bottom Line: The effect of learning-by-doing was assessed by comparing the performance of eight subjects (BtSt) who only used the mobile substitution device for the tests, to that of three subjects who, in addition, practiced with it for four hours daily in their normal life (BtSc and BcSc); two subjects who did not use the device at all (BtSn and BcSn) allowed assessment of its use in the tasks we employed.The three subjects who freely used the device daily as well as during tests were faster and more accurate than those who used it during tests only; however, long-term blindfolding did not notably influence performance.Together, the results demonstrate that the device allowed blindfolded subjects to increasingly know where something was by listening, and indicate that practice in naturalistic conditions effectively improved "visual" localization performance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Experimental Psychology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany. Michael.Proulx@uni-duesseldorf.de

ABSTRACT

Background: Sensory substitution devices for the blind translate inaccessible visual information into a format that intact sensory pathways can process. We here tested image-to-sound conversion-based localization of visual stimuli (LEDs and objects) in 13 blindfolded participants.

Methods and findings: Subjects were assigned to different roles as a function of two variables: visual deprivation (blindfolded continuously (Bc) for 24 hours per day for 21 days; blindfolded for the tests only (Bt)) and system use (system not used (Sn); system used for tests only (St); system used continuously for 21 days (Sc)). The effect of learning-by-doing was assessed by comparing the performance of eight subjects (BtSt) who only used the mobile substitution device for the tests, to that of three subjects who, in addition, practiced with it for four hours daily in their normal life (BtSc and BcSc); two subjects who did not use the device at all (BtSn and BcSn) allowed assessment of its use in the tasks we employed. The impact of long-term sensory deprivation was investigated by blindfolding three of those participants throughout the three week-long experiment (BcSn, BcSn/c, and BcSc); the other ten subjects were only blindfolded during the tests (BtSn, BtSc, and the eight BtSt subjects). Expectedly, the two subjects who never used the substitution device, while fast in finding the targets, had chance accuracy, whereas subjects who used the device were markedly slower, but showed much better accuracy which improved significantly across our four testing sessions. The three subjects who freely used the device daily as well as during tests were faster and more accurate than those who used it during tests only; however, long-term blindfolding did not notably influence performance.

Conclusions: Together, the results demonstrate that the device allowed blindfolded subjects to increasingly know where something was by listening, and indicate that practice in naturalistic conditions effectively improved "visual" localization performance.

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Related in: MedlinePlus

An illustration of the sensory substitution device and its conversion principles.A) The vOICe program is installed on the notebook computer in the backpack. The camera is hidden in the glasses and the earphones provide the result of the image-to-sound conversion. B) Conversion principles for The vOICe.
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pone-0001840-g001: An illustration of the sensory substitution device and its conversion principles.A) The vOICe program is installed on the notebook computer in the backpack. The camera is hidden in the glasses and the earphones provide the result of the image-to-sound conversion. B) Conversion principles for The vOICe.

Mentions: The present study used an image-to-sound conversion program, The vOICe [11], to examine the perceptual learning of manual localization based on the sounds generated by translating the images from a video camera hidden in sunglasses (see Figure 1). The use of a head-mounted rather than a handheld camera (cf. [8]) requires a different coordinate system and different sensory-motor contingencies for using the camera to allow one to grasp objects. Localization was assessed in three experiments. In the first, the participants had to manually indicate the location of a lit LED in a horizontal array of 18 possible target locations. The second experiment examined whether the learning would transfer to a more challenging LED task where there were 164 possible target locations. In the third experiment objects that were placed singly on a large table had to be located and grasped. On the basis of subjects' grasping precision we were also able to consider the ability of participants to take account of features of the object, such as its size.


Seeing 'where' through the ears: effects of learning-by-doing and long-term sensory deprivation on localization based on image-to-sound substitution.

Proulx MJ, Stoerig P, Ludowig E, Knoll I - PLoS ONE (2008)

An illustration of the sensory substitution device and its conversion principles.A) The vOICe program is installed on the notebook computer in the backpack. The camera is hidden in the glasses and the earphones provide the result of the image-to-sound conversion. B) Conversion principles for The vOICe.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2267489&req=5

pone-0001840-g001: An illustration of the sensory substitution device and its conversion principles.A) The vOICe program is installed on the notebook computer in the backpack. The camera is hidden in the glasses and the earphones provide the result of the image-to-sound conversion. B) Conversion principles for The vOICe.
Mentions: The present study used an image-to-sound conversion program, The vOICe [11], to examine the perceptual learning of manual localization based on the sounds generated by translating the images from a video camera hidden in sunglasses (see Figure 1). The use of a head-mounted rather than a handheld camera (cf. [8]) requires a different coordinate system and different sensory-motor contingencies for using the camera to allow one to grasp objects. Localization was assessed in three experiments. In the first, the participants had to manually indicate the location of a lit LED in a horizontal array of 18 possible target locations. The second experiment examined whether the learning would transfer to a more challenging LED task where there were 164 possible target locations. In the third experiment objects that were placed singly on a large table had to be located and grasped. On the basis of subjects' grasping precision we were also able to consider the ability of participants to take account of features of the object, such as its size.

Bottom Line: The effect of learning-by-doing was assessed by comparing the performance of eight subjects (BtSt) who only used the mobile substitution device for the tests, to that of three subjects who, in addition, practiced with it for four hours daily in their normal life (BtSc and BcSc); two subjects who did not use the device at all (BtSn and BcSn) allowed assessment of its use in the tasks we employed.The three subjects who freely used the device daily as well as during tests were faster and more accurate than those who used it during tests only; however, long-term blindfolding did not notably influence performance.Together, the results demonstrate that the device allowed blindfolded subjects to increasingly know where something was by listening, and indicate that practice in naturalistic conditions effectively improved "visual" localization performance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Experimental Psychology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany. Michael.Proulx@uni-duesseldorf.de

ABSTRACT

Background: Sensory substitution devices for the blind translate inaccessible visual information into a format that intact sensory pathways can process. We here tested image-to-sound conversion-based localization of visual stimuli (LEDs and objects) in 13 blindfolded participants.

Methods and findings: Subjects were assigned to different roles as a function of two variables: visual deprivation (blindfolded continuously (Bc) for 24 hours per day for 21 days; blindfolded for the tests only (Bt)) and system use (system not used (Sn); system used for tests only (St); system used continuously for 21 days (Sc)). The effect of learning-by-doing was assessed by comparing the performance of eight subjects (BtSt) who only used the mobile substitution device for the tests, to that of three subjects who, in addition, practiced with it for four hours daily in their normal life (BtSc and BcSc); two subjects who did not use the device at all (BtSn and BcSn) allowed assessment of its use in the tasks we employed. The impact of long-term sensory deprivation was investigated by blindfolding three of those participants throughout the three week-long experiment (BcSn, BcSn/c, and BcSc); the other ten subjects were only blindfolded during the tests (BtSn, BtSc, and the eight BtSt subjects). Expectedly, the two subjects who never used the substitution device, while fast in finding the targets, had chance accuracy, whereas subjects who used the device were markedly slower, but showed much better accuracy which improved significantly across our four testing sessions. The three subjects who freely used the device daily as well as during tests were faster and more accurate than those who used it during tests only; however, long-term blindfolding did not notably influence performance.

Conclusions: Together, the results demonstrate that the device allowed blindfolded subjects to increasingly know where something was by listening, and indicate that practice in naturalistic conditions effectively improved "visual" localization performance.

Show MeSH
Related in: MedlinePlus