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The rubber foot illusion.

Crea S, D'Alonzo M, Vitiello N, Cipriani C - J Neuroeng Rehabil (2015)

Bottom Line: Lower-limb amputation causes the individual a huge functional impairment due to the lack of adequate sensory perception from the missing limb.The development of an augmenting sensory feedback device able to restore some of the missing information from the amputated limb may improve embodiment, control and acceptability of the prosthesis.The results, collected from 19 healthy subjects, demonstrated that it is possible to elicit the perception of possessing a rubber foot when modality-matched stimulations are provided synchronously on the biological foot and to the corresponding rubber foot areas.

View Article: PubMed Central - PubMed

Affiliation: The BioRobotics Institute, Scuola Superiore Sant'Anna, viale Rinaldo Piaggio, Pontedera (PI), Italy. s.crea@sssup.it.

ABSTRACT

Background: Lower-limb amputation causes the individual a huge functional impairment due to the lack of adequate sensory perception from the missing limb. The development of an augmenting sensory feedback device able to restore some of the missing information from the amputated limb may improve embodiment, control and acceptability of the prosthesis.

Findings: In this work we transferred the Rubber Hand Illusion paradigm to the lower limb. We investigated the possibility of promoting body ownership of a fake foot, in a series of experiments fashioned after the RHI using matched or mismatched (vibrotactile) stimulation. The results, collected from 19 healthy subjects, demonstrated that it is possible to elicit the perception of possessing a rubber foot when modality-matched stimulations are provided synchronously on the biological foot and to the corresponding rubber foot areas. Results also proved that it is possible to enhance the illusion even with modality-mismatched stimulation, even though illusion was lower than in case of modality-matched stimulation.

Conclusions: We demonstrated the possibility of promoting a Rubber Foot Illusion with both matched and mismatched stimulation.

No MeSH data available.


Related in: MedlinePlus

Average ratings of the self-assessment questionnaire. a 9 statements. Illusion statements are from 1 to 3. Suggestion statements are from 4 to 9. b Vividness of the illusion. c Prevalence of the illusion. CS = Congruent Synchronous, CA = Congruent Asynchronous, IS = Incongruent Synchronous, IA = Incongruent Asynchronous. * indicates p<.05, *** indicates p<.001
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Fig2: Average ratings of the self-assessment questionnaire. a 9 statements. Illusion statements are from 1 to 3. Suggestion statements are from 4 to 9. b Vividness of the illusion. c Prevalence of the illusion. CS = Congruent Synchronous, CA = Congruent Asynchronous, IS = Incongruent Synchronous, IA = Incongruent Asynchronous. * indicates p<.05, *** indicates p<.001

Mentions: Results of the self-assessment questionnaire substantially agree with previous studies on the hand, with illusion statements rated significantly higher than control statements (aimed to assess suggestibility of the subjects) (Fig.2(a)). Statistical differences between the average scores on illusion and suggestion statements (p<0.05) were found in all the four experimental conditions (t test, CS, p<.0001; CA, p=.0003; IS, p<.0001; IA, p=.0194). Moreover, a two-way repeated-measures ANOVA on average values of illusion statements revealed a significant main effect of timing (F(1,18)=76.74,p<.0001) and modality (F(1,18)=19.81,p=.0003). No statistically significant interaction between the effects of timing and modality was found (F(1,18)=2.39,p=.1395). From the post-hoc multiple comparison with Tukey-Kramer adjustment, both matched and mismatched modalities revealed higher illusion in the synchronous conditions than in asynchronous ones (CS vs CA p<.0001, IS vs IA p=.0001). Also, in the illusion statements, the modality (congruent vs incongruent) revealed a statistical difference between synchronous conditions, with higher illusion in the congruent than in the incongruent conditions (CS vs IS p=.0005; CA vs IA p=.0548).Fig. 2


The rubber foot illusion.

Crea S, D'Alonzo M, Vitiello N, Cipriani C - J Neuroeng Rehabil (2015)

Average ratings of the self-assessment questionnaire. a 9 statements. Illusion statements are from 1 to 3. Suggestion statements are from 4 to 9. b Vividness of the illusion. c Prevalence of the illusion. CS = Congruent Synchronous, CA = Congruent Asynchronous, IS = Incongruent Synchronous, IA = Incongruent Asynchronous. * indicates p<.05, *** indicates p<.001
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4559902&req=5

Fig2: Average ratings of the self-assessment questionnaire. a 9 statements. Illusion statements are from 1 to 3. Suggestion statements are from 4 to 9. b Vividness of the illusion. c Prevalence of the illusion. CS = Congruent Synchronous, CA = Congruent Asynchronous, IS = Incongruent Synchronous, IA = Incongruent Asynchronous. * indicates p<.05, *** indicates p<.001
Mentions: Results of the self-assessment questionnaire substantially agree with previous studies on the hand, with illusion statements rated significantly higher than control statements (aimed to assess suggestibility of the subjects) (Fig.2(a)). Statistical differences between the average scores on illusion and suggestion statements (p<0.05) were found in all the four experimental conditions (t test, CS, p<.0001; CA, p=.0003; IS, p<.0001; IA, p=.0194). Moreover, a two-way repeated-measures ANOVA on average values of illusion statements revealed a significant main effect of timing (F(1,18)=76.74,p<.0001) and modality (F(1,18)=19.81,p=.0003). No statistically significant interaction between the effects of timing and modality was found (F(1,18)=2.39,p=.1395). From the post-hoc multiple comparison with Tukey-Kramer adjustment, both matched and mismatched modalities revealed higher illusion in the synchronous conditions than in asynchronous ones (CS vs CA p<.0001, IS vs IA p=.0001). Also, in the illusion statements, the modality (congruent vs incongruent) revealed a statistical difference between synchronous conditions, with higher illusion in the congruent than in the incongruent conditions (CS vs IS p=.0005; CA vs IA p=.0548).Fig. 2

Bottom Line: Lower-limb amputation causes the individual a huge functional impairment due to the lack of adequate sensory perception from the missing limb.The development of an augmenting sensory feedback device able to restore some of the missing information from the amputated limb may improve embodiment, control and acceptability of the prosthesis.The results, collected from 19 healthy subjects, demonstrated that it is possible to elicit the perception of possessing a rubber foot when modality-matched stimulations are provided synchronously on the biological foot and to the corresponding rubber foot areas.

View Article: PubMed Central - PubMed

Affiliation: The BioRobotics Institute, Scuola Superiore Sant'Anna, viale Rinaldo Piaggio, Pontedera (PI), Italy. s.crea@sssup.it.

ABSTRACT

Background: Lower-limb amputation causes the individual a huge functional impairment due to the lack of adequate sensory perception from the missing limb. The development of an augmenting sensory feedback device able to restore some of the missing information from the amputated limb may improve embodiment, control and acceptability of the prosthesis.

Findings: In this work we transferred the Rubber Hand Illusion paradigm to the lower limb. We investigated the possibility of promoting body ownership of a fake foot, in a series of experiments fashioned after the RHI using matched or mismatched (vibrotactile) stimulation. The results, collected from 19 healthy subjects, demonstrated that it is possible to elicit the perception of possessing a rubber foot when modality-matched stimulations are provided synchronously on the biological foot and to the corresponding rubber foot areas. Results also proved that it is possible to enhance the illusion even with modality-mismatched stimulation, even though illusion was lower than in case of modality-matched stimulation.

Conclusions: We demonstrated the possibility of promoting a Rubber Foot Illusion with both matched and mismatched stimulation.

No MeSH data available.


Related in: MedlinePlus