Limits...
The mechanism of speech processing in congenital amusia: evidence from Mandarin speakers.

Liu F, Jiang C, Thompson WF, Xu Y, Yang Y, Stewart L - PLoS ONE (2012)

Bottom Line: However, they performed as well as controls on word identification, and on statement-question identification and discrimination in natural speech.Only when the tasks relied mainly on pitch sensitivity did amusics show impaired performance compared to controls.Further studies on a larger sample of Mandarin amusics and on amusics of other language backgrounds are needed to consolidate these results.

View Article: PubMed Central - PubMed

Affiliation: Center for the Study of Language and Information, Stanford University, Stanford, California, United States of America. liufang@uchicago.edu

ABSTRACT
Congenital amusia is a neuro-developmental disorder of pitch perception that causes severe problems with music processing but only subtle difficulties in speech processing. This study investigated speech processing in a group of Mandarin speakers with congenital amusia. Thirteen Mandarin amusics and thirteen matched controls participated in a set of tone and intonation perception tasks and two pitch threshold tasks. Compared with controls, amusics showed impaired performance on word discrimination in natural speech and their gliding tone analogs. They also performed worse than controls on discriminating gliding tone sequences derived from statements and questions, and showed elevated thresholds for pitch change detection and pitch direction discrimination. However, they performed as well as controls on word identification, and on statement-question identification and discrimination in natural speech. Overall, tasks that involved multiple acoustic cues to communicative meaning were not impacted by amusia. Only when the tasks relied mainly on pitch sensitivity did amusics show impaired performance compared to controls. These findings help explain why amusia only affects speech processing in subtle ways. Further studies on a larger sample of Mandarin amusics and on amusics of other language backgrounds are needed to consolidate these results.

Show MeSH

Related in: MedlinePlus

Boxplots of amusics and controls' pitch thresholds (in st) in the two psychophysical tasks.(A) pitch change detection, and (B) pitch direction discrimination.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3275596&req=5

pone-0030374-g006: Boxplots of amusics and controls' pitch thresholds (in st) in the two psychophysical tasks.(A) pitch change detection, and (B) pitch direction discrimination.

Mentions: Figure 6 shows the results on pitch threshold tasks (see Table S6 for individual scores). Mixed-effects ANOVA with Subject (individual participants) as the random effect, Group (amusic versus control) the between-subject factor, and Task (pitch change detection versus pitch direction discrimination) the within-subject factor revealed significant effects of Group [F(1,24) = 6.21, p = 0.02] and Task [F(1,24) = 6.78, p = 0.02], but not Group×Task interaction [F(1,24) = 0.01, p = 0.94]. That is, amusics had significantly higher pitch thresholds than controls for both pitch change detection and pitch direction discrimination. Both groups showed a tendency to perform better on pitch direction discrimination than pitch change detection. No significant correlation was found for either group between their performances on the two pitch threshold tasks.


The mechanism of speech processing in congenital amusia: evidence from Mandarin speakers.

Liu F, Jiang C, Thompson WF, Xu Y, Yang Y, Stewart L - PLoS ONE (2012)

Boxplots of amusics and controls' pitch thresholds (in st) in the two psychophysical tasks.(A) pitch change detection, and (B) pitch direction discrimination.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3275596&req=5

pone-0030374-g006: Boxplots of amusics and controls' pitch thresholds (in st) in the two psychophysical tasks.(A) pitch change detection, and (B) pitch direction discrimination.
Mentions: Figure 6 shows the results on pitch threshold tasks (see Table S6 for individual scores). Mixed-effects ANOVA with Subject (individual participants) as the random effect, Group (amusic versus control) the between-subject factor, and Task (pitch change detection versus pitch direction discrimination) the within-subject factor revealed significant effects of Group [F(1,24) = 6.21, p = 0.02] and Task [F(1,24) = 6.78, p = 0.02], but not Group×Task interaction [F(1,24) = 0.01, p = 0.94]. That is, amusics had significantly higher pitch thresholds than controls for both pitch change detection and pitch direction discrimination. Both groups showed a tendency to perform better on pitch direction discrimination than pitch change detection. No significant correlation was found for either group between their performances on the two pitch threshold tasks.

Bottom Line: However, they performed as well as controls on word identification, and on statement-question identification and discrimination in natural speech.Only when the tasks relied mainly on pitch sensitivity did amusics show impaired performance compared to controls.Further studies on a larger sample of Mandarin amusics and on amusics of other language backgrounds are needed to consolidate these results.

View Article: PubMed Central - PubMed

Affiliation: Center for the Study of Language and Information, Stanford University, Stanford, California, United States of America. liufang@uchicago.edu

ABSTRACT
Congenital amusia is a neuro-developmental disorder of pitch perception that causes severe problems with music processing but only subtle difficulties in speech processing. This study investigated speech processing in a group of Mandarin speakers with congenital amusia. Thirteen Mandarin amusics and thirteen matched controls participated in a set of tone and intonation perception tasks and two pitch threshold tasks. Compared with controls, amusics showed impaired performance on word discrimination in natural speech and their gliding tone analogs. They also performed worse than controls on discriminating gliding tone sequences derived from statements and questions, and showed elevated thresholds for pitch change detection and pitch direction discrimination. However, they performed as well as controls on word identification, and on statement-question identification and discrimination in natural speech. Overall, tasks that involved multiple acoustic cues to communicative meaning were not impacted by amusia. Only when the tasks relied mainly on pitch sensitivity did amusics show impaired performance compared to controls. These findings help explain why amusia only affects speech processing in subtle ways. Further studies on a larger sample of Mandarin amusics and on amusics of other language backgrounds are needed to consolidate these results.

Show MeSH
Related in: MedlinePlus