The integration of prosodic speech in high functioning autism: a preliminary FMRI study.

BACKGROUND: Autism is a neurodevelopmental disorder characterized by a specific triad of symptoms such as abnormalities in social interaction, abnormalities in communication and restricted activities and interests. While verbal autistic subjects may present a correct mastery of the formal aspects of speech, they have difficulties in prosody (music of speech), leading to communication disorders. Few behavioural studies have revealed a prosodic impairment in children with autism, and among the few fMRI studies aiming at assessing the neural network involved in language, none has specifically studied prosodic speech. The aim of the present study was to characterize specific prosodic components such as linguistic prosody (intonation, rhythm and emphasis) and emotional prosody and to correlate them with the neural network underlying them. METHODOLOGY/PRINCIPAL FINDINGS: We used a behavioural test (Profiling Elements of the Prosodic System, PEPS) and fMRI to characterize prosodic deficits and investigate the neural network underlying prosodic processing. Results revealed the existence of a link between perceptive and productive prosodic deficits for some prosodic components (rhythm, emphasis and affect) in HFA and also revealed that the neural network involved in prosodic speech perception exhibits abnormal activation in the left SMG as compared to controls (activation positively correlated with intonation and emphasis) and an absence of deactivation patterns in regions involved in the default mode. CONCLUSIONS/SIGNIFICANCE: These prosodic impairments could not only result from activation patterns abnormalities but also from an inability to adequately use the strategy of the default network inhibition, both mechanisms that have to be considered for decreasing task performance in High Functioning Autism.

Distinctive alterations of the cingulum bundle during aging and Alzheimer's disease.

Brain imaging studies have revealed frontal disruption during aging and parieto-temporal disruption during Alzheimer's disease (AD). The present study aims at developing a specific method based on precise anatomical landmarks for assessing the integrity all along the course of the cingulum bundle, so as to determine if it presents the classical aging and AD dissociation. Five regions of interest (ROIs) were placed on fractional anisotropy (FA) maps all along the cingulum in 15 young (Gyoung), 15 70-year-old (Gold), and 15 AD subjects (Galz). An age-related decrease of FA occurred in the anterior part of the bundle. Moreover, a specific alteration of the supero-posterior region of the cingulum during AD was observed since mean FA values as well as mean number of fibers were significantly decreased in Galz compared to Gold and Gyoung. This multiple ROIs placement allows for revealing distinctive alterations of the cingulum bundle during aging and AD, which could constitute the anatomical basis for the distinctive functional disconnection recently described in the literature using functional connectivity at rest.

Alteration of attentional blink in high functioning autism: a pilot study.

Autism is characterized by deficits in attention. However, no study has investigated the dynamics of attentional processes in autistic patients yet. The attentional blink (AB) paradigm provides information about the temporal dynamics of attention in particular about the allocation and the duration of an attentional episode. We compared 11 high functioning autistic patients with 15 control participants on a classical AB task. Autistic patients exhibited a deficit in rapidly allocated attentional resources. Further investigations such as coupling AB evaluation with neuroimaging data and/or increasing the size of groups, would allow for investigating the neurobiological substrates of these AB alterations in autistic patients.