Dia: dilluns 29 d'abril del 2024
Hora: 12.30 h
Lloc: aula 52.939 - 9a planta edifici 52. Roc Boronat - Campus del Poblenou - UPF, i també en línia. 

Resum: 
This study compares the development of imitation skills in typically developing children (TD) and children with neurodevelopmental disorders (NDD) of preschool and early school age by focusing on multimodal imitation (i.e., the imitation of target sentences, their prosody and accompanying gestures) and analyzes its link with oral language skills. Participants were 290 Catalan-Spanish bilingual children (129 girls; 235 TD, 55 NDD) between ages 3 and 7 (Mmonths = 59.6 (±9.5)). Following a transdiagnostic approach, the NDD group included children with and at risk of Autism and DLD. All children undertook the Multimodal Imitation Task in which they were asked to repeat contextualized sentences interacting with a toy while reproducing prosodic contours (i.e., statements, questions, exclamations) and imitating co-speech gestures (e.g., conventional, iconic). The children also undertook two language tasks: an expressive pragmatic test and a narrative telling task. LME models showed that the NDD group had overall significantly lower scores for all imitation scores than the TD group Moreover, age had a general effect on all three imitation scores, with scores improving with age across the children. Interestingly, a significant interaction of age and group was found for gesture, showing that only the TD group improved significantly in gesture imitation as they got older. We further analyzed separately the subset of responses when the children performed only gestural imitation but did not imitate the speech (gesture-only, 11% of tokens in the NDD group and 3% in the TD group) and the subset of responses when the children performed both gestural and speech imitation (gesture-speech integration). In gesture-only responses, gestural imitation of the NDD group was significantly better than that of the TD group but only in the early ages (3-4). However, this effect was not found in gesture-speech integration responses. Moreover, while for the TD group all imitation scores were positively correlated, in the NDD group the gesture imitation did not correlate with sentence imitation. In the same lines, while for the TD group all imitation scores were strongly correlated with pragmatic and narrative language scores, in the NDD group, only prosodic and sentence imitation correlated with the language scores but not gesture. 

These results show different imitation patterns for TD and NDD children. In TD children, all imitation skills are systematically improved with age, correlated with one another and associated with the development of complex oral language skills (pragmatics and narrative). In turn, NDD children show a significant delay in the acquisition of imitation skills, with gesture being particularly impaired, since they improved speech and prosody imitation but not gesture imitation. Clearly, gesture imitation in the NDD children behaves differently from their other imitation abilities, since it was not correlated with speech imitation nor with other oral language abilities. Furthermore, higher percentage of gesture-only responses of the NDD children and higher gesture imitation scores in the early ages might indicate a compensatory gesture-based technique they apply to make up for the inability to imitate speech well. The study pinpoints different developmental paths of multimodal imitation in the two populations and highlights the importance of considering gesture-speech integration rather than gesture production only.