title: Convergent and Divergent fMRI Responses in Children and Adults to Increasing Language Production Demands.
abstract: In adults, patterns of neural activation associated with perhaps the most basic language skill--overt object naming--are extensively modulated by the psycholinguistic and visual complexity of the stimuli. Do children's brains react similarly when confronted with increasing processing demands, or they solve this problem in a different way? Here we scanned 37 children aged 7-13 and 19 young adults who performed a well-normed picture-naming task with 3 levels of difficulty. While neural organization for naming was largely similar in childhood and adulthood, adults had greater activation in all naming conditions over inferior temporal gyri and superior temporal gyri/supramarginal gyri. Manipulating naming complexity affected adults and children quite differently: neural activation, especially over the dorsolateral prefrontal cortex, showed complexity-dependent increases in adults, but complexity-dependent decreases in children. These represent fundamentally different responses to the linguistic and conceptual challenges of a simple naming task that makes no demands on literacy or metalinguistics. We discuss how these neural differences might result from different cognitive strategies used by adults and children during lexical retrieval/production as well as developmental changes in brain structure and functional connectivity.
authors.affiliation: Birkbeck-UCL Centre for NeuroImaging, London, UK Centre for Brain and Cognitive Development, Birkbeck, University of London, London, UK.
authors.forename: Saloni
authors.initials: S
authors.lastname: Krishnan
authors.affiliation: Department of Neurosciences and Mental Health, Imperial College London, London, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Leech
authors.affiliation: Institute of Cognitive Neuroscience, UCL, London, UK.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Mercure
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck, University of London, London, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Lloyd-Fox
authors.affiliation: Birkbeck-UCL Centre for NeuroImaging, London, UK Centre for Brain and Cognitive Development, Birkbeck, University of London, London, UK.
authors.forename: Frederic
authors.initials: F
authors.lastname: Dick
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002648:Child; D005260:Female; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology; D055815:Young Adult
keywords: development; fMRI; language production; task difficulty; word generation