Language lateralization in individuals with callosal agenesis: An fMRI study

Pelletier, Isabelle; Paquette, Natacha; Leporé, Franco; Rouleau, Isabelle; Sauerwein, Catherine H.; Rosa, Christine J. De; Leroux, Jean-Maxime; Gravel, Pierre; Valois, Katja; Andermann, Frédérick; Saint-Amour, Dave; Lassonde, Maryse

doi:10.1016/j.neuropsychologia.2011.03.028

Cited by 21 publications

(19 citation statements)

References 80 publications

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“…Siffredi et al Neuropsychologia 106 (2017) 71-82 Duquette et al, 2008;Paiement et al, 2010), language lateralisation (e.g., Pelletier et al, 2011) or emotionally laden information (Lungu and Stip, 2012). To our knowledge, this is the first study to explore brain activity related to WM in this population.…”

Section: Discussionmentioning

confidence: 82%

Neural correlates of working memory in children and adolescents with agenesis of the corpus callosum: An fMRI study

et al. 2017

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A B S T R A C TThe ability to temporarily maintain relevant information in mind in the presence of interference or distracting information, also called working memory (WM), is critical for higher cognitive functions and cognitive development. In typically developing (TD) children, WM is underpinned by a fronto-parietal network of interacting left and right brain regions. Developmental absence (agenesis) of the corpus callosum (AgCC) is a congenital brain malformation resulting from disruption of corpus callosum formation. This study aims to investigate functional organisation of WM in children and adolescents with AgCC using functional magnetic resonance imaging (fMRI). Nine children with AgCC and a comparison group of sixteen TD children aged 8-17 years completed an fMRI WM paradigm designed to enable investigation of different WM processes, i.e., encoding, maintenance and retrieval. We found that AgCC children recruited globally similar brain regions as the TD comparison group during the WM task, despite significant disparity in brain development, i.e., bilateral occipitofrontal activations during verbal encoding, and bilateral fronto-parietal executive control network during retrieval. However, compared to their TD peers, children with AgCC seemed less able to engage lateralised brain systems specialised for particular memory material (i.e. less supramarginal activations for verbal material and less fusiform activations for face processing) and particular memory process (i.e. absence of right-predominant activations during retrieval). Group differences in the pattern of activation might also reflect different cognitive strategies to cope with competition in processing resources with different susceptibility to concurrent tasks (verbal vs visual), such as differential recruitment of associative visual areas and executive prefrontal regions in the AgCC compared with the TD group depending on the concurrent task completed during maintenance. This study provides a first step towards a better understanding of functional brain networks underlying higher cognitive functions in children with AgCC.

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Section: Discussionmentioning

confidence: 82%

Neural correlates of working memory in children and adolescents with agenesis of the corpus callosum: An fMRI study

et al. 2017

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“…The results revealed an increase in [HbO] and a decrease in [HbR] in the anterior frontal cortex with more activation in the left than right anterior frontal cortex, whereas activation was bilateral in the prefrontal cortex. The verbal fluency task also demonstrated consistent results in functional magnetic resonance imaging (fMRI) and magneto-encephalography (MEG) in determining language localization and lateralization (Yamamoto et al 2006; Pelletier et al 2011; Gallagher et al 2008; Pirmoradi et al 2010). …”

Section: Introductionmentioning

confidence: 67%

Functional near‐infrared spectroscopy for the assessment of overt reading

et al. 2012

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Functional near-infrared spectroscopy (fNIRS) has become increasingly established as a promising technique for monitoring functional brain activity. To our knowledge, no study has yet used fNIRS to investigate overt reading of irregular words and nonwords with a full coverage of the cerebral regions involved in reading processes. The aim of our study was to design and validate a protocol using fNIRS for the assessment of overt reading. Twelve healthy French-speaking adults underwent one session of fNIRS recording while performing an overt reading of 13 blocks of irregular words and nonwords. Reading blocks were separated by baseline periods during which participants were instructed to fixate a cross. Sources (n = 55) and detectors (n = 16) were placed bilaterally over frontal, temporal, parietal, and occipital regions. Two wavelengths were used: 690 nm, more sensitive to deoxyhemoglobin (HbR) concentration changes, and 830 nm, more sensitive to oxyhemoglobin (HbO) concentration changes. For all participants, total hemoglobin (HbT) concentrations (HbO + HbR) were significantly higher than baseline for both irregular word and nonword reading in the inferior frontal gyri, the middle and superior temporal gyri, and the occipital cortices bilaterally. In the temporal gyri, although the difference was not significant, [HbT] values were higher in the left hemisphere. In the bilateral inferior frontal gyri, higher [HbT] values were found in nonword than in irregular word reading. This activation could be related to the grapheme-to-phoneme conversion characterizing the phonological pathway of reading. Our findings confirm that fNIRS is an appropriate technique to assess the neural correlates of overt reading.

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“…Bilateral language representation without clear lateralisation has first been reported during speech production and perception with fMRI (Riecker, et al 2007). However, in a more recent study, no difference in receptive and expressive speech lateralisation was reported between patients and controls, except for frontal regions in the latter task (Pelletier, et al 2011). As for structural asymmetries, strong leftward perisylvian asymmetries for both the planum temporale and planum parietale have been described in a single subject with complete agenesis (Jancke, et al 1997), and asymmetry in white matter microstructure has been investigated only for the ventral cingulum bundle (Nakata, et al 2009) so far.…”

Section: Iv5 Are White Matter Asymmetries Preserved In the Case Of mentioning

confidence: 90%

“…Comparing functional and structural connectivity patterns in the same patients is now the next step to go to highlight the complexity of the developing networks and to explore their underlying mechanisms. As an example, it has recently been suggested that corpus callosum inhibition may actually not be criticial for the establishment of lateralised language function (Pelletier, et al 2011): language lateralisation in a receptive speech task was not modified in the case of corpus callosum agenesis, but frontal activations during expressive speech were more bilateral in acallosal participants than in controls. Future anatomo-functional research on younger infants with corpus callosum agenesis will probably open a wide range of opportunities to investigate this question.…”

Section: Iv7 Future Directionsmentioning

confidence: 99%

Organising white matter in a brain without corpus callosum fibres

Bénézit

Hertz-Pannier

Dehaene‐Lambertz

et al. 2015

Cortex

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Isolated corpus callosum dysgenesis (CCD) is a congenital malformation which occurs during early development of the brain. In this study, we aimed to identify and describe its consequences beyond the lack of callosal fibres, on the morphology, microstructure and asymmetries of the main white matter bundles with diffusion imaging and fibre tractography. Seven children aged between 9 and 13 years old and seven age- and gender-matched control children were studied. First, we focused on bundles within the mesial region of the cerebral hemispheres: the corpus callosum, Probst bundles and cingulum which were selected using a conventional region-based approach. We demonstrated that the Probst bundles have a wider connectivity than the previously described rostrocaudal direction, and a microstructure rather distinct from the cingulum but relatively close to callosal remnant fibres. A sigmoid bundle was found in two partial ageneses. Second, the corticospinal tract, thalamic radiations and association bundles were extracted automatically via an atlas of adult white matter bundles to overcome bias resulting from a priori knowledge of the bundles' anatomical morphology and trajectory. Despite the lack of callosal fibres and the colpocephaly observed in CCD, all major white matter bundles were identified with a relatively normal morphology, and preserved microstructure (i.e. fractional anisotropy, mean diffusivity) and asymmetries. Consequently the bundles' organisation seems well conserved in brains with CCD. These results await further investigations with functional imaging before apprehending the cognition variability in children with isolated dysgenesis.

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Language lateralization in individuals with callosal agenesis: An fMRI study

Cited by 21 publications

References 80 publications

Neural correlates of working memory in children and adolescents with agenesis of the corpus callosum: An fMRI study

Neural correlates of working memory in children and adolescents with agenesis of the corpus callosum: An fMRI study

Functional near‐infrared spectroscopy for the assessment of overt reading

Organising white matter in a brain without corpus callosum fibres

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