Stroke disconnectome decodes reading networks.

Cognitive functional neuroimaging has been around for over 30 years and has shed light on the brain areas relevant for reading. However, new methodological developments enable mapping the interaction between functional imaging and the underlying white matter networks. In this study, we used such a novel method, called the disconnectome, to decode the reading circuitry in the brain. We used the resulting disconnection patterns to predict a typical lesion that would lead to reading deficits after brain damage. Our results suggest that white matter connections critical for reading include fronto-parietal U-shaped fibres and the vertical occipital fasciculus (VOF). The lesion most predictive of a reading deficit would impinge on the left temporal, occipital, and inferior parietal gyri. This novel framework can systematically be applied to bridge the gap between the neuropathology of language and cognitive neuroscience.

Typical and atypical language brain organization based on intrinsic connectivity and multitask functional asymmetries.

Based on the joint investigation in 287 healthy volunteers (150 left-Handers (LH)) of language task-induced asymmetries and intrinsic connectivity strength of the sentence-processing supramodal network, we show that individuals with atypical rightward language lateralization (N = 30, 25 LH) do not rely on an organization that simply mirrors that of typical leftward lateralized individuals. Actually, the resting-state organization in the atypicals showed that their sentence processing was underpinned by left and right networks both wired for language processing and highly interacting by strong interhemispheric intrinsic connectivity and larger corpus callosum volume. Such a loose hemispheric specialization for language permits the hosting of language in either the left and/or right hemisphere as assessed by a very high incidence of dissociations across various language task-induced asymmetries in this group.

Cognitive Mediators of School-Related Socio-Adaptive Behaviors in ASD and Intellectual Disability Pre- and Adolescents: A Pilot-Study in French Special Education Classrooms.

The school inclusion of students with autism is still a challenge. To address the cognitive underpinnings of school-related adaptive behaviors, 27 students with autism and 18 students with intellectual and/or severe learning disability, aged from 11 to 17, were recruited. They underwent socio-emotional processing and executive functioning assessments, as well as school-related adaptive behavior and quality of life measurements. Both groups performed equally on socio-emotional and executive assessments, and they reported the same low quality of life. However, students with autism exhibited more limitations than the students with intellectual disabilities on complex school adaptive behaviors (socialization and autonomy) and problem behaviors, but both groups performed equally on more basic adaptive behaviors (school routines, communication). Multiple regression analyses highlighted between-group differences in terms of adaptive functioning profiles, which were linked with different cognitive predictors according to students' medical conditions. The greater school-related limitations of students with autism were mostly explained by socio-emotional performance, while IQ (intellectual quotient) mostly explained the comparable between-group limitations. The low quality of life of both groups was slightly explained by executive performance. The role of both socio-emotional and executive functioning in students' adaptive behaviors and quality of life suggests remediation targets for promoting the school inclusion of students with autism.

Large-scale plurimodal networks common to listening to, producing and reading word lists: an fMRI study combining task-induced activation and intrinsic connectivity in 144 right-handers.

We aimed at identifying plurimodal large-scale networks for producing, listening to and reading word lists based on the combined analyses of task-induced activation and resting-state intrinsic connectivity in 144 healthy right-handers. In the first step, we identified the regions in each hemisphere showing joint activation and joint asymmetry during the three tasks. In the left hemisphere, 14 homotopic regions of interest (hROIs) located in the left Rolandic sulcus, precentral gyrus, cingulate gyrus, cuneus and inferior supramarginal gyrus (SMG) met this criterion, and 7 hROIs located in the right hemisphere were located in the preSMA, medial superior frontal gyrus, precuneus and superior temporal sulcus (STS). In a second step, we calculated the BOLD temporal correlations across these 21 hROIs at rest and conducted a hierarchical clustering analysis to unravel their network organization. Two networks were identified, including the WORD-LIST_CORE network that aggregated 14 motor, premotor and phonemic areas in the left hemisphere plus the right STS that corresponded to the posterior human voice area (pHVA). The present results revealed that word-list processing is based on left articulatory and storage areas supporting the action-perception cycle common not only to production and listening but also to reading. The inclusion of the right pHVA acting as a prosodic integrative area highlights the importance of prosody in the three modalities and reveals an intertwining across hemispheres between prosodic (pHVA) and phonemic (left SMG) processing. These results are consistent with the motor theory of speech postulating that articulatory gestures are the central motor units on which word perception, production, and reading develop and act together.

The neural processing of second language comprehension modulated by the degree of proficiency: a listening connected speech FMRI study.

While the neural network encompassing the processing of the mother tongue (L1) is well defined and has revealed the existence of a bilateral ventral pathway and a left dorsal pathway in which 3 loops have been defined, the question of the processing of a second language (L2) is still a matter of debate. Among variables accounting for the discrepancies in results, the degree of L2 proficiency appears to be one of the main factors. The present study aimed at assessing both pathways in L2, making it possible to determine the degree of mastery of the different speech components (prosody, phonology, semantics and syntax) that are intrinsically embedded within connected speech and that vary according to the degree of proficiency using high degrees of prosodic information. Two groups of high and moderate proficiency in L2 performed an fMRI comprehension task in L1 and L2. The modifications in brain activity observed within the dorsal and the ventral pathways according to L2 proficiency suggest that different processes of L2 are supported by differences in the integrated activity within distributed networks that included the left STSp, the left Spt and the left pars triangularis.

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.

Assessing prosodic skills in five European languages: cross-linguistic differences in typical and atypical populations.

Following demand for a prosody assessment procedure, the test Profiling Elements of Prosody in Speech-Communication (PEPS-C), has been translated from English into Spanish, French, Flemish and Norwegian. This provides scope to examine receptive and expressive prosodic ability in Romance (Spanish and French) as well as Germanic (English and Flemish) languages, and includes the possibility of assessing these skills with regard to lexical tone (Norwegian). Cross-linguistic similarities and differences relevant to the translation are considered. Preliminary findings concerning 8-year-old neurotypical children speaking the five languages are reported. The appropriateness of investigating contrastive stress in Romance as well as Germanic languages is considered: results are reported for assessing this skill in Spanish and English speakers and suggest that in Spanish it is acquired much later than in English. We also examine the feasibility of assessing and comparing prosodic disorder in the five languages, using assessments of prosody in Spanish and English speakers with Williams syndrome as an example. We conclude that, with caveats, the original design of the UK test may indicate comparable stages of prosodic development in neurotypical children and is appropriate for the evaluation of prosodic skills for adults and children, both neurotypical and with impairment, in all five languages.

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.

Cerebral mechanisms of prosodic sensory integration using low-frequency bands of connected speech.

Even if speech perception has been reported to involve both left and right hemispheres, converging data have posited the existence of a functional asymmetry at the level of secondary auditory cortices. Using fMRI in 12 right-handed French men listening passively to long connected speech stimuli, we addressed the question of neuronal networks involved in the integration of low frequency bands of speech by comparing 1) differences in brain activity in two listening conditions (FN, NF) differing in the integration of pitch modulations (in FN, low frequencies, obtained by a low-pass filter, are addressed to the left ear while the whole acoustic message is simultaneously addressed to the right ear, NF being the reverse position); 2) differences in brain activity induced by high and low degrees of prosodic expression (expressive vs. flat); and 3) effects of the same connected speech stimulus in the two listening conditions. Each stimulus induced a specific cerebral network, the flat one weakening activations which were mainly reduced to the bilateral STG for both listening conditions. In the expressive condition, the specific sensory integration FN results in an increase of the articulatory loop and new recruitments such as right BA6-44, left BA39-40, the left posterior insula and the bilateral BA30. This finding may be accounted for by the existence of temporal windows differing both in length and in acoustic cues decoding, strengthening the "asymmetric sampling in time" hypothesis posited by Poeppel (Speech Commun 2003; 41:245-255). Such an improvement of prosodic integration could find applications in the rehabilitation of some speech disturbances.

Cerebral mechanisms of prosodic integration: evidence from connected speech.

Using functional Magnetic Resonance Imaging (fMRI) and long connected speech stimuli, we addressed the question of neuronal networks involved in prosodic integration by comparing (1) differences in brain activity when hearing connected speech stimuli with high and low degrees of prosodic expression; (2) differences in brain activity in two different diotic listening conditions (normal speech delivery to both ears, i.e., NN; and low-pass-filtered speech delivery to both ears, i.e., FF); and (3) effects of high and low degrees of prosodic information in the NN and FF conditions. Twelve right-handed French men listened passively to the stimuli. Each stimulus induced a specific cerebral network, the flat one weakening activations, which were mainly reduced to the bilateral STG for both listening conditions. High degrees of prosodic information were found to trigger right specific activations in a wider neuronal network involved in speech integration (such as BA44, BA21-22 and BA39-40) than low degrees of prosodic information did. More precisely, the right BA44 was found to be specifically involved in the process of F(0) modulations, which are the main acoustic correlate of prosody. Not only do the results achieved in the present experiment using 30-s-long connected speech stimuli show the involvement of a bilateral neuronal network but they also strongly suggest that high degrees of prosodic information elicit activations in a wider neuronal network involved in speech perception than low degrees of prosodic information do.