Developmental changes in brain regions involved in phonological and orthographic processing during spoken language processing

Abstract

Developmental differences in brain activation of 9-to 15-year-old children were examined during an auditory rhyme decision task to spoken words using functional magnetic resonance imaging (fMRI). As a group, children showed activation in left superior/middle temporal gyri (BA 22, 21), right middle temporal gyrus (BA 21), dorsal (BA 45, pars opercularis) and ventral (BA 46, pars triangularis) aspects of left inferior frontal gyrus, and left fusiform gyrus (BA 37). There was a developmental increase in activation in left middle temporal gyrus (BA 22) across all lexical conditions, suggesting that automatic semantic processing increases with age regardless of task demands. Activation in left dorsal inferior frontal gyrus also showed developmental increases for the conflicting (e.g. PINT-MINT) compared to the non-conflicting (e.g. PRESS-LIST) non-rhyming conditions, indicating that this area becomes increasingly involved in strategic phonological processing in the face of conflicting orthographic and phonological representations. Left inferior temporal/fusiform gyrus (BA 37) activation was also greater for the conflicting (e.g. PINT-MINT) condition, and a developmental increase was found in the positive relationship between individuals' reaction time and activation in left lingual/fusiform gyrus (BA 18) in this condition, indicating an age-related increase in the association between longer reaction times and greater visual-orthographic processing in this conflicting condition. These results suggest that orthographic processing is automatically engaged by children in a task that does not require access to orthographic information for correct performance, especially when orthographic and phonological representations conflict, and especially for longer response latencies in older children.

Apraxia of speech from a right frontal lesion

“…Finally, poor performance on a silent rhyming task and a decreased digit span are consistent with the assumption that apraxia of speech may interfere with working memory tasks through an impairment of 'inner speech' processes (Waters, Rochon, & Caplan, 1992;Ziegler, 2008). Rhyming judgement which involves deciding on the phonological structure of words is linked to a dominant, perisylvian network also incorporating the left inferior frontal gyrus (Burton, Locasto, Krebs-Noble, & Gullapalli, 2005;Cone, Burman, Bitan, Bolger, & Booth, 2008;Lurito, Kareken, Lowe, Chen, & Mathews, 2000;MacSweeney, Brammer, Waters, & Goswami, 2009). As in some other cases (Bonilha, Moser, Rorden, Baylis, & Fridriksson, 2006) AOS was not coupled with orofacial apraxia, possibly due to the less consistent lateralization of orofacial motor control (Bizzozero et al, 2000;Mani & Levine, 1988).…”

Morphological and Functional Development of the Auditory Nervous System

“…In contrast, ongoing maturation (refl ected by declining rCBF and attributed to dendritic pruning) continued into adolescence in higher order cognitive areas, such as the angular gyrus. Similar results were obtained when developmental differences in brain activation of 9-to 15-year-old children were examined by fMRI (Cone et al 2008 ) . During an auditory rhyme decision task to spoken words, a developmental increase in activation in the left superior temporal gyrus (BA 22) was seen across all lexical conditions, suggesting that automatic semantic processing increases with age regardless of task demands.…”

Distinct patterns of functional and structural neuroplasticity associated with learning Morse code

“…This notion is supported by the fact that performance on rhyming judgements is influenced by spelling patterns, especially when orthographic and phonological representations conflict. Interestingly BOLD activity related to such conflicts is seen in the left fusiform and inferior temporal gyrus (Cone et al, 2008), projecting close to both the cluster of GM change and BOLD activity in response to all four stimuli. During the learning period writing down letters and words -although not applied in the scanner -was an essential part of the learning and practicing process.…”

“…This cluster bordered on the cluster of GM increase (see below). On one hand the left occipitotemporal region is known to be involved in semantic judgments to both visually and acoustically presented stimuli (Cohen et al, 2004;Flowers et al, 2004;Cone et al, 2008). It could be hypothesised that this region was directly involved in stimulus processing, which would imply that, although there was no learning associated with the tone on the cognitive/behavioural level, recognition of the tone within the 4-alternative forced choice task used in our paradigm, would resort to an activation in the occipitotemporal cortex that it would share with the other stimuli.…”