15th International Congress of Phonetic Sciences (ICPhS-15)

Barcelona, Spain
August 3-9, 2003

Specialization of Posterior Prefrontal Cortex: Segmentation or Something Else?

Jack Gandour (1), Mario Dzemidzic (2), Donald Wong (2), Mark Lowe (2), Yisheng Xu (1), Yunxia Tong (1), Xiaojian Li (1)

(1) Purdue University, USA
(2) Indiana University, USA

One of the challenges for cognitive neuroscience is to identify functional roles of brain regions involved in complex decision-making phonological tasks. The Chinese language provides an optimal window for investigating extraction of segmental and suprasegmental units. The aim of this fMRI study is to elucidate neural mechanisms involved in extraction of Chinese consonants, rhymes, and tones in non-minimal and minimal pairs. Triplets of minimal or non-minimal pairs of Chinese monosyllables were constructed to compare consonants, rhymes, and tones. Ten Chinese and English subjects were asked to selectively attend to intrasyllabic components of the target syllables and make discrimination judgments. In comparison to the English group, the Chinese group showed increased activation in the left posterior prefrontal cortex (PFC) when processing consonants, rhymes, or tones, no matter the stimulus type, minimal or non-minimal. Comparisons of non-minimal to minimal pairs within the Chinese group revealed activation of areas outside of the left posterior PFC for consonants and rhymes; for tones, bilateral activation in anterior and posterior prefrontal regions, and in predominantly left-sided inferior parietal regions. Comparisons of consonants, rhymes, and tones within stimulus type (minimal, non-minimal) show left posterior prefrontal activation for rhymes in the Chinese group, tones in the English group. These findings support the notion of an attention-modulated neural network underlying different aspects of phonological processing.

Full Paper

Bibliographic reference.  Gandour, Jack / Dzemidzic, Mario / Wong, Donald / Lowe, Mark / Xu, Yisheng / Tong, Yunxia / Li, Xiaojian (2003): "Specialization of posterior prefrontal cortex: segmentation or something else?", In ICPhS-15, 2525-2528.