Early- and Late-Onset Blindness Both Curb Audiotactile Integration on the Parchment-Skin Illusion

Abstract

It has been shown that congenital blindness can lead to anomalies in the integration of auditory and tactile information, at least under certain conditions. In the present study, we used the parchment-skin illusion, a robust illustration of sound-biased perception of touch based on changes in frequency, to investigate the specificities of audiotactile interactions in early- and late-onset blind individuals. Blind individuals in both groups did not experience any illusory change in tactile perception when the frequency of the auditory signal was modified, whereas sighted individuals consistently experienced the illusion. This demonstration that blind individuals had reduced susceptibility to an auditory-tactile illusion suggests either that vision is necessary for the establishment of audiotactile interactions or that auditory and tactile information can be processed more independently in blind individuals than in sighted individuals. In addition, the results obtained in late-onset blind participants suggest that visual input may play a role in the maintenance of audiotactile integration.

Audiotactile interaction can change over time in cochlear implant users

“…No significant differences were found between groups when auditory stimuli were not modified ( U = 164.5; p = 0.638) or when high frequencies were amplified ( U = 158.0; p = 0.511). Then, as in previous research using the same experimental technique (see Champoux et al, 2011), we performed a Kruskal–Wallis ANOVA between groups (control; “long-term CI users; “short-term CI users) for the three experimental conditions (no alteration; high-frequency boost; high-frequency cut). There was a significant difference between the changes in tactile sensation, both when high frequencies were amplified [ c 2 (2) = 9.52; p = 0.009] or attenuated [ c 2 (2) = 11.67; p = 0.003].…”

“…For CI users, the headphones were positioned in a normal fashion with the speaker over the CI’s microphone located behind the helix of the pinna. During the experiment, three different auditory conditions were used (for an explicit detailing of the experimental procedure, see Champoux et al, 2011). In the first experimental condition, the auditory stimulus was the unaltered recorded sound.…”

“…As such, the present study made use of a uni-dimensional scale (dry-moist) to minimize any potential ambiguities in qualifying palmar skin changes. As in previous investigation using the exact same procedure (see Champoux et al, 2011), non-parametric statistics were used, as it is designated for datasets without a uniform response criterion and when using scale ratings (in this case, /-5/to/+5/).…”

“…The parchment-skin illusion (Jousmäki and Hari, 1998) is also a non-speech illusory percept in which an amplification or reduction of high-frequency content from the sound generated by rubbing hands together results in an alteration of the experienced palmar dryness/moistness. This sound-induced alteration of touch perception appears to be a robust case of cross-modal fusion in the spectral domain (see also Guest et al, 2002; Champoux et al, 2011). The parchment-skin illusion is one of the earliest demonstrations of the importance of spectral auditory inputs on tactile perception.…”

Late- but not early-onset blindness impairs the development of audio-haptic multisensory integration

“…These findings show that unisensory processing in the remaining senses seems to depend on visual calibration early in development. However, much less is known about whether multisensory processes are affected by visual impairment in a similar way, although few studies tried to address this research question (Hötting and Röder, 2004;Champoux et al, 2011).…”