Publications from 2009

Chou TL, Chen CW, Wu MY & Booth JR (2009). The role of the inferior frontal gyrus and inferior parietal lobule in semantic processing of Chinese characters. Experimental Brain Research, 198, 465-475. [pdf]

Functional magnetic resonance imaging (fMRI) was used to explore the neural correlates of semantic judgments to Chinese characters. Adult participants were asked to indicate if character pairs were related in meaning that were arranged in a continuous variable according to association strength. This parametric manipulation allowed for a more precise determination of the role of left inferior parietal lobule in processing meaning, which has not been reported in previous Chinese studies. Consistent with previous findings in English, participants showed activation in left inferior frontal gyrus (BA 47, 45) and left posterior middle temporal gyrus (BA 21). Characters with stronger semantic association elicited greater activation in left inferior parietal lobule (BA 39), suggesting stronger integration of highly related semantic features. By contrast, characters with weaker semantic association elicited greater activation in both an anterior ventral region (BA 47) and a mid-ventral region of left inferior frontal gyrus (BA 45), suggesting a controlled retrieval process and a selection process. Our findings of association strength are discussed in a proposed neuro-anatomical model of semantic processing.

Chou TL, Chen CW, Fan LY, Chen SY & Booth JR (2009). A cultural influence on reading for meaning in the developing brain. Frontiers in Human Neuroscience, 3, 1-9. [pdf]

Functional magnetic resonance imaging (fMRI) was used to explore the neural correlates of semantic judgments in a group of 8- to 15-year-old Chinese children. Participants were asked to indicate if pairs of Chinese characters presented visually were related in meaning. The related pairs were arranged in a continuous variable according to association strength. Pairs of characters with weaker semantic association elicited greater activation in the mid ventral region (BA 45) of left inferior frontal gyrus, suggesting increased demands on the process of selecting appropriate semantic features. By contrast, characters with stronger semantic association elicited greater activation in left inferior parietal lobule (BA 39), suggesting stronger integration of highly related features. In addition, there was a developmental increase, similar to previously reported findings in English, in left posterior middle temporal gyrus (BA 21), suggesting that older children have more elaborated semantic representations. There were additional age-related increases in the posterior region of left inferior parietal lobule and in the ventral regions of left inferior frontal gyrus, suggesting that reading acquisition relies more on the mapping from orthography to semantics in Chinese children as compared to previously reported findings in English.

Liu L, Deng X, Peng DL, Cao F, Ding GS, Jin Z, Zeng Y, Li K, Zhu L, Fan N, Deng Y & Booth JR (2009). Modality- and task-specific brain regions involved in Chinese lexical processing. Journal of Cognitive Neuroscience, 21, 1473-1487. [pdf]

Functional magnetic resonance imaging (fMRI) was used to examine lexical processing in native adult Chinese speakers. A 2 task (semantics, phonology) ×2 modality (visual, auditory) within subject design was adopted. The semantic task involved a meaning association judgment and the phonological task involved a rhyming judgment, to two sequentially presented words. The overall effect across tasks and modalities was used to identify 7 regions of interest (ROI), including left fusiform gyrus (FG), left superior temporal gyrus (STG), left ventral inferior frontal gyrus (VIFG), left middle temporal gyrus (MTG), left dorsal inferior frontal gyrus (DIFG), left inferior parietal lobule (IPL) and left middle frontal gyrus (MFG). ROI analyses revealed two modality-specific areas: FG for visual and STG for auditory; and three task-specific areas: IPL and DIFG for phonology, and VIFG for semantics. Greater DIFG activation was associated with conflicting tonal information between words for the auditory rhyming task suggesting this region’s role in strategic phonological processing and greater VIFG activation was correlated with lower association between words for both the auditory and visual meaning task suggesting this region’s role in retrieval and selection of semantic representations. The modality- and task-specific effects in Chinese revealed by this study are similar to those found in alphabetical languages. Unlike English, we found that MFG was both modality- and task-specific suggesting that MFG may be responsible for the visuo-spatial analysis of Chinese characters and orthography-to-phonology integration at a syllablic level, demanded by the logographic and monosyllabic nature of written Chinese.

Bitan T, Cheon J, Lu D, Burman DD & Booth JR (2009). Developmental increase in top-down and bottom-up processing in a phonological task: An effective connectivity, fMRI study. Journal of Cognitive Neuroscience, 21, 1135-1145. [pdf]

We examined age-related changes in the interactions among brain regions in children performing rhyming judgments on visually presented words. The difficulty of the task was manipulated by including a conflict between task relevant (phonological) information and task-irrelevant (orthographic) information. The conflicting conditions included pairs of words that rhyme despite having different spelling patterns (jazz-has), or words that do not rhyme despite having similar spelling patterns (pint-mint). These were contrasted with non-conflicting pairs that have similar orthography and phonology (dime-lime) or different orthography and phonology (press-list). Using fMRI we examined effective connectivity among five left hemisphere regions of interest: fusiform gyrus (FG), inferior frontal gyrus (IFG), intraparietal sulcus (IPS), lateral temporal cortex (LTC) and medial frontal gyrus (MeFG). Age-related increases were observed in the influence of IFG and FG on LTC, but only in conflicting conditions. These results reflect a developmental increase in the convergence of bottom-up and top-down information on LTC. In older children top-down control process may selectively enhance the sensitivity of LTC to bottom-up information from FG. This may be evident especially in situations that require selective enhancement of task-relevant vs. task-irrelevant information. Altogether these results provide a direct evidence for a developmental increase in top-down control processes in language processing. The developmental increase in bottom-up processing may be secondary to the enhancement of top-down processes.

Burman DD & Booth JR (2009). Music rehearsal increases perceptual span for music. Music Perception, 26, 303-320. [pdf]

Despite evidence of improved visual processing among skilled musicians, the effect of music rehearsal on the effective visual field (the “perceptual span”) has never been directly examined. Following 1 - 20 rehearsals, 11 skilled and 10 unskilled adult musicians specified whether a variant note appeared within a melodic sequence of 3 - 18 notes, presented onscreen for 200 ms in a tachistoscopic task designed to evaluate the perceptual span. Initially, skilled musicians showed a slightly larger perceptual span for challenging passages (5 notes vs. 4 notes for unskilled musicians). Perceptual spans increased incrementally in both groups; although skill differences in span size disappeared by 20 rehearsals (span of 11 notes), reliance on musical cues for detecting variant notes differed with musical skill. Correlation between improvements in perceptual span and performance speed suggests perceptual learning could underlie early improvements in performance during music rehearsals.

Cao F, Peng DL, Liu L, Jin Z, Fan N, Deng Y & Booth JR (2009). Developmental differences of neurocognitive networks for phonological and semantics processing in Chinese word reading. Human Brain Mapping, 30, 797-809. [pdf]

Developmental differences in the neurocognitive networks for phonological and semantic processing in Chinese word reading were examined in 13 adults and 13 children using functional magnetic resonance imaging (fMRI). Rhyming and semantic association judgments were made to two-character words that were presented sequentially in the visual modality. These lexical tasks were compared with a nonlinguistic control task involving judgment of line patterns. The first main finding was that adults showed greater activation than children in left inferior parietal lobule for the rhyming as compared to the meaning task, suggesting greater specialization of phonological processing in adults. The second main finding was that adults showed greater activation than children in right middle occipital gyrus on both the meaning and rhyming task, suggesting adults more effectively engage right hemisphere brain regions involved in the visual-spatial analysis of Chinese characters. The third main finding was that children who had better performance in the rhyming task on characters with conflicting orthographic and phonological information relative to characters with non-conflicting information showed greater activation in left middle frontal gyrus, suggesting greater engagement of brain regions involved in the integration of orthography and phonology.