Functional anatomy of cognitive development

Gaillard, W. D.; Hertz-Pannier, Lucie; Mott, Stephen H.; Barnett, Alan S.; LeBihan, D.; Theodore, William H.

doi:10.1212/wnl.54.1.180

Cited by 389 publications

(271 citation statements)

References 33 publications

Supporting

Mentioning

233

Contrasting

Unclassified

Order By: Relevance

“…Consistent with reports in the literature for children and adult subjects [30][31][32], fMRI expressive language tasks produced reliable activation of left frontal language areas in this cohort of healthy teenagers. Our finding that fMRI results were observable for every subject while MEG activations were less pronounced is consistent with another study comparing fMRI and MEG in adults during a naming task [33].…”

Section: Discussionsupporting

confidence: 90%

Localization of Broca's area using verb generation tasks in the MEG: Validation against fMRI

Pang

Wang

Malone

et al. 2011

Neuroscience Letters

View full text Add to dashboard Cite

Functional MRI (fMRI) is routinely used to non-invasively localize language areas. Magnetoencephalography (MEG) is being explored as an alternative technique. MEG tasks to localize receptive language are well established although there are no standardized tasks to localize expressive language areas. We developed two expressive language tasks for MEG and validated their localizations against fMRI data. Ten right-handed adolescents (μ=17.5 years) were tested with fMRI and MEG on two tasks: verb generation to pictures and verb generation to words. MEG and fMRI data were normalized and overlaid. The number of overlapping voxels activated in fMRI and MEG were counted for each subject, for each task, at different thresholding levels. For picture verb generation, there was 100% concordance between MEG and fMRI lateralization, and for word verb generation, there was 75% concordance. A count showed 79.6% overlap of voxels activated by both MEG and fMRI for picture verb generation and 50.2% overlap for word verb generation. The percentage overlap decreased with increasingly stringent activation thresholds. Our novel MEG expressive language tasks successfully identified neural regions involved in language production and showed high concordance with fMRI laterality. Percentage overlap of activated voxels was also high when validated against fMRI, but showed task-specific and threshold-related effects. The high concordance and high percentage overlap between fMRI and MEG activations confirm the validity of our new MEG task. Furthermore, the higher concordance from the picture verb generation task suggests that this is a promising task for use in the young clinical population.

show abstract

Section: Discussionsupporting

confidence: 90%

Localization of Broca's area using verb generation tasks in the MEG: Validation against fMRI

Pang

Wang

Malone

et al. 2011

Neuroscience Letters

View full text Add to dashboard Cite

show abstract

“…Letter fluency is an executive function task mediated by cortical and subcortical brain structures in healthy individuals. Functional imaging studies of verbal fluency have reported left inferior frontal and dorsolateral prefrontal activation (Abrahams et al, 2003;Fu et al, 2002;Gaillard et al, 2000;Gourovitch et al, 2000;Paulesu et al, 1997;Phelps et al, 1997) and right cerebellar activation (Fu et al, 2002;Hubrich-Ungureanu et al, 2002;Weiss et al, 2003). In addition, lesion studies support the role of the frontal lobes (e.g., Baldo et al, 2001) and cerbellum in executive function tasks (Akshoomoff et al, 1992;Levisohn et al, 2000;Paradiso et al, 1997;Riva and Giorgi, 2000;Schmahmann and Sherman, 1997).…”

Section: Discussionmentioning

confidence: 97%

N-acetyl aspartate in autism spectrum disorders: Regional effects and relationship to fMRI activation

et al. 2007

View full text Add to dashboard Cite

Rapid progress in our understanding of macrostructural abnormalities in autism spectrum disorders (ASD) has occurred in recent years. However, the relationship between the integrity of neural tissue and neural function has not been previously investigated. Single-voxel proton magnetic resonance spectroscopy and functional magnetic resonance imaging of an executive functioning task was obtained in 13 high functioning adolescents and adults with ASD and 13 agematched controls. The ASD group showed significant reductions in N-acetyl aspartate (NAA) in all brain regions combined and a specific reduction in left frontal cortex compared to controls. Regression analyses revealed a significant group interaction effect between frontal and cerebellar NAA. In addition, a significant positive semi-partial correlation between left frontal lobe NAA and frontal lobe functional activation was found in the ASD group. These findings suggest that widespread neuronal dysfunction is present in high functioning individuals with ASD. Hypothesized developmental links between frontal and cerebellar vermis neural abnormalities were supported, in that impaired neuronal functioning in the vermis was associated with impaired neuronal functioning in the frontal lobes in the ASD group. Furthermore, this study provided the first direct evidence of the relationship between abnormal functional activation in prefrontal cortex and neuronal dysfunction in ASD.

show abstract

“…The letter fluency task relies on basic word knowledge and initiation of efficient lexical retrieval strategies to name appropriate items whereas the category fluency task depends to a greater extent on overlearned semantic knowledge. Both tasks are mediated by left prefrontal cortex in most typically developing individuals (Abrahams et al, 2003;Fu et al, 2002;Gaillard et al, 2000;Gourovitch et al, 2000;Paulesu et al, 1997;Phelps et al, 1997;Szaflarski et al, 2002). Individuals with ASD show impairments on behavioral measure of the letter fluency task relative to typically developing controls (Rumsey and Hamburger, 1988;Rumsey and Hamburger, 1990;Turner, 1999, but see Minshew et al, 1997 adults with severe dyslexia (Rumsey and Hamburger, 1990) and clinical norms (Kleinhans et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Atypical functional lateralization of language in autism spectrum disorders

et al. 2008

View full text Add to dashboard Cite

Impaired language is a prominent behavioral marker of autism spectrum disorders (ASD), but its neurobiological underpinnings are incompletely understood. We studied letter and category fluency in 14 high functioning ASD individuals and 14 age-matched controls. Each fluency condition was compared to self-paced repetition of the word "nothing." Responses were recorded to monitor performance. In letter fluency, the ASD group had significantly greater activation than controls in the right frontal and right superior temporal lobe. Between-group differences were not observed in left prefrontal cortex. By examining functional asymmetry in frontal cortex, we found that the ASD group had significantly reduced lateralization of activation patterns in letter fluency compared to the controls. In category fluency, no between-group differences in lateralization were found, in light of greater bilateral activation in controls. These findings indicate reduced hemispheric differentiation for certain verbal fluency tasks in ASD, consistent with some previous evidence of atypical functional and structural asymmetries in autism. Abnormal functional organization may contribute to the language impairment seen in ASD.

show abstract

Functional anatomy of cognitive development

Cited by 389 publications

References 33 publications

Localization of Broca's area using verb generation tasks in the MEG: Validation against fMRI

Localization of Broca's area using verb generation tasks in the MEG: Validation against fMRI

N-acetyl aspartate in autism spectrum disorders: Regional effects and relationship to fMRI activation

Atypical functional lateralization of language in autism spectrum disorders

Contact Info

Product

Resources

About