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Tactile feedback improves auditory spatial localization.

Gori M, Vercillo T, Sandini G, Burr D - Front Psychol (2014)

Bottom Line: Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially congruent.Our results suggest that the tactile system can be used to recalibrate the auditory sense of space.These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality.

View Article: PubMed Central - PubMed

Affiliation: Robotics Brain and Cognitive Sciences Department, Istituto Italiano di Tecnologia Genoa, Italy.

ABSTRACT
Our recent studies suggest that congenitally blind adults have severely impaired thresholds in an auditory spatial bisection task, pointing to the importance of vision in constructing complex auditory spatial maps (Gori et al., 2014). To explore strategies that may improve the auditory spatial sense in visually impaired people, we investigated the impact of tactile feedback on spatial auditory localization in 48 blindfolded sighted subjects. We measured auditory spatial bisection thresholds before and after training, either with tactile feedback, verbal feedback, or no feedback. Audio thresholds were first measured with a spatial bisection task: subjects judged whether the second sound of a three sound sequence was spatially closer to the first or the third sound. The tactile feedback group underwent two audio-tactile feedback sessions of 100 trials, where each auditory trial was followed by the same spatial sequence played on the subject's forearm; auditory spatial bisection thresholds were evaluated after each session. In the verbal feedback condition, the positions of the sounds were verbally reported to the subject after each feedback trial. The no feedback group did the same sequence of trials, with no feedback. Performance improved significantly only after audio-tactile feedback. The results suggest that direct tactile feedback interacts with the auditory spatial localization system, possibly by a process of cross-sensory recalibration. Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially congruent. Our results suggest that the tactile system can be used to recalibrate the auditory sense of space. These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality.

No MeSH data available.


(A) Image of the vibrotactile devices used for the tactile feedback. The device comprises a series of vibrotactile units (on the underside), each of which can be driven individually. (B) Image representing the tactile feedback condition. The audio spatial threshold was first measured by the bisection technique. They were then given a first session of audio-tactile feedback, the spatial audio threshold was measured again, a second session of audio-tactile feedback and the spatial audio threshold was then repeated.
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Figure 1: (A) Image of the vibrotactile devices used for the tactile feedback. The device comprises a series of vibrotactile units (on the underside), each of which can be driven individually. (B) Image representing the tactile feedback condition. The audio spatial threshold was first measured by the bisection technique. They were then given a first session of audio-tactile feedback, the spatial audio threshold was measured again, a second session of audio-tactile feedback and the spatial audio threshold was then repeated.

Mentions: We tested 48 sighted subjects (age: 24.8 ± 0.6 years). Participants were blindfolded before entering the room, so they had no notion of the room or speaker layout. They were sat at the center of a bank of nine speakers, spanning ±17.5° of visual angle, aligned with the fifth speaker (at the center of the array), 90 cm away. In order to decrease auditory precision (to allow for more improvement), we positioned the array obliquely with respect to the subjects (see Figure 1). Subjects were assigned at random to one of five groups: tactile feedback (n = 11); verbal feedback (n = 11); no feedback (n = 14); rotated (n = 5); rotated–reversed (n = 7).


Tactile feedback improves auditory spatial localization.

Gori M, Vercillo T, Sandini G, Burr D - Front Psychol (2014)

(A) Image of the vibrotactile devices used for the tactile feedback. The device comprises a series of vibrotactile units (on the underside), each of which can be driven individually. (B) Image representing the tactile feedback condition. The audio spatial threshold was first measured by the bisection technique. They were then given a first session of audio-tactile feedback, the spatial audio threshold was measured again, a second session of audio-tactile feedback and the spatial audio threshold was then repeated.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4202795&req=5

Figure 1: (A) Image of the vibrotactile devices used for the tactile feedback. The device comprises a series of vibrotactile units (on the underside), each of which can be driven individually. (B) Image representing the tactile feedback condition. The audio spatial threshold was first measured by the bisection technique. They were then given a first session of audio-tactile feedback, the spatial audio threshold was measured again, a second session of audio-tactile feedback and the spatial audio threshold was then repeated.
Mentions: We tested 48 sighted subjects (age: 24.8 ± 0.6 years). Participants were blindfolded before entering the room, so they had no notion of the room or speaker layout. They were sat at the center of a bank of nine speakers, spanning ±17.5° of visual angle, aligned with the fifth speaker (at the center of the array), 90 cm away. In order to decrease auditory precision (to allow for more improvement), we positioned the array obliquely with respect to the subjects (see Figure 1). Subjects were assigned at random to one of five groups: tactile feedback (n = 11); verbal feedback (n = 11); no feedback (n = 14); rotated (n = 5); rotated–reversed (n = 7).

Bottom Line: Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially congruent.Our results suggest that the tactile system can be used to recalibrate the auditory sense of space.These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality.

View Article: PubMed Central - PubMed

Affiliation: Robotics Brain and Cognitive Sciences Department, Istituto Italiano di Tecnologia Genoa, Italy.

ABSTRACT
Our recent studies suggest that congenitally blind adults have severely impaired thresholds in an auditory spatial bisection task, pointing to the importance of vision in constructing complex auditory spatial maps (Gori et al., 2014). To explore strategies that may improve the auditory spatial sense in visually impaired people, we investigated the impact of tactile feedback on spatial auditory localization in 48 blindfolded sighted subjects. We measured auditory spatial bisection thresholds before and after training, either with tactile feedback, verbal feedback, or no feedback. Audio thresholds were first measured with a spatial bisection task: subjects judged whether the second sound of a three sound sequence was spatially closer to the first or the third sound. The tactile feedback group underwent two audio-tactile feedback sessions of 100 trials, where each auditory trial was followed by the same spatial sequence played on the subject's forearm; auditory spatial bisection thresholds were evaluated after each session. In the verbal feedback condition, the positions of the sounds were verbally reported to the subject after each feedback trial. The no feedback group did the same sequence of trials, with no feedback. Performance improved significantly only after audio-tactile feedback. The results suggest that direct tactile feedback interacts with the auditory spatial localization system, possibly by a process of cross-sensory recalibration. Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially congruent. Our results suggest that the tactile system can be used to recalibrate the auditory sense of space. These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality.

No MeSH data available.