Impaired neural discrimination of emotional speech prosody in children with autism spectrum disorder and language impairment

Abstract

Autism spectrum disorders (ASD) are characterized by deficient social and communication skills, including difficulties in perceiving speech prosody. The present study addressed processing of emotional prosodic changes (sad, scornful and commanding) in natural word stimuli in typically developed school-aged children and in children with ASD and language impairment. We found that the responses to a repetitive word were diminished in amplitude in the children with ASD, reflecting impaired speech encoding. Furthermore, the amplitude of the MMN/LDN component, reflecting cortical discrimination of sound changes, was diminished in the children with ASD for the scornful deviant. In addition, the amplitude of the P3a, reflecting involuntary orienting to attention-catching changes, was diminished in the children with ASD for the scornful deviant and tended to be smaller for the sad deviant. These results suggest that prosody processing in ASD is impaired at various levels of neural processing, including deficient pre-attentive discrimination and involuntary orientation to speech prosody.

Atypical speech versus non-speech detection and discrimination in 4- to 6- yr old children with autism spectrum disorder: An ERP study

“…Consistent with this hypothesis, Boddaert and colleagues found that listening to complex synthetic speech-like stimuli can elicit abnormal cortical processing in children with autism in a similar fashion as to speech stimuli [46]. Taken together, the evidence to date suggests atypical processing of prosody and emotional prosodic cues in speech [13, 27] and deficient processing of vocal sounds, both speech and non-speech, in children with ASD [28]. By demonstrating atypical lateralization of the speech mismatch effect, the current results support the conclusions from a recent ERP study suggesting that atypicalities in responses to speech versus non-speech sounds might be related to the delayed maturation of vocal sound processing, either speech or non-speech [28], most likely due to the social nature of the stimuli.…”

“…Based upon previous findings [11, 13, 22]; see also [25]for a review), we predicted between-group differences in the responses to speech and non-speech sounds; these would be reflected in ERP components associated with early cognitive processing of speech (e.g., 300 ms post-stimulus), associated with the recognition and classification of auditory stimuli [21, 25, 26]. Due to the nature of the paired repetition ERP paradigm employed here, we expected between group differences in speech processing to be reflected in responses to the Speech Mismatch versus Speech Match trials (Speech Mismatch effect), as well as in responses to Nonspeech Mismatch versus Nonspeech Match trials (Nonspeech mismatch effect).…”

“…It is difficult to draw a big picture of speech processing dysfunctions in ASD when combining previous findings, since these studies are not directly compatible on physical and language characteristics of stimuli (i.e. meaningful: [19, 13, 20]) versus meaningless stimuli [16–18], or on participants’ verbal abilities. More specifically, one major limitation of previous research is the inclusion of children with ASD with a much lower verbal IQ [11]: mean of 8.9 years with mean verbal age of 3.4 years; [21]: 9.4 years with verbal age of 4.9 years; 3: 10.5 yrs with verbal age of 5.8 years).…”

“…In addition, the results of a more recent study utilizing the MMN paradigm demonstrated that processing of emotional components of speech, such as prosody, is diminished at different levels of processing in children with ASD. More specifically, between-group differences in the MMN and P3a component activity were observed in response to a deviant emotional speech stimulus [13]. Taken together, these results suggest that attentional orienting to, and detection of, speech sounds is not universally impaired in children with ASD.…”

Characteristics of the Understanding and Expression of Emotional Prosody among Children with Autism Spectrum Disorder

“…Significant differences in brain response (by use of ERPs) between children with and without ASD processing emotional prosodic changes in natural word stimuli have been found [52]. Eigsti, et al reported significant differences in neural activation (by use of fMRI) between adolescents with and without ASD processing affective and grammatical prosody stimuli [53].…”