Intonation processing deficits of emotional words among Mandarin Chinese speakers with congenital amusia: an ERP study.
BACKGROUND
Congenital amusia is a disorder that is known to affect the processing of musical pitch. Although individuals with amusia rarely show language deficits in daily life, a number of findings point to possible impairments in speech prosody that amusic individuals may compensate for by drawing on linguistic information. Using EEG, we investigated (1) whether the processing of speech prosody is impaired in amusia and (2) whether emotional linguistic information can compensate for this impairment.


METHODS
Twenty Chinese amusics and 22 matched controls were presented pairs of emotional words spoken with either statement or question intonation while their EEG was recorded. Their task was to judge whether the intonations were the same.


RESULTS
Amusics exhibited impaired performance on the intonation-matching task for emotional linguistic information, as their performance was significantly worse than that of controls. EEG results showed a reduced N2 response to incongruent intonation pairs in amusics compared with controls, which likely reflects impaired conflict processing in amusia. However, our EEG results also indicated that amusics were intact in early sensory auditory processing, as revealed by a comparable N1 modulation in both groups.


CONCLUSIONS
We propose that the impairment in discriminating speech intonation observed among amusic individuals may arise from an inability to access information extracted at early processing stages. This, in turn, could reflect a disconnection between low-level and high-level processing.
Department of Psychology, Macquarie University Sydney, NSW, Australia ; Medical Psychological Institute, The Second Xiangya Hospital, Central South University Changsha, China.
Xuejing
X
Lu
Department of Psychology, Macquarie University Sydney, NSW, Australia.
Hao Tam
HT
Ho
Department of Speech, Hearing and Phonetic Sciences, University College London London, UK.
Fang
F
Liu
Medical Psychological Institute, The Second Xiangya Hospital, Central South University Changsha, China.
Daxing
D
Wu
Department of Psychology, Macquarie University Sydney, NSW, Australia.
William F
WF
Thompson
ERP; conflict processing; congenital amusia; intonation processing; pitch perception