The neural basis of Chinese morphological processing
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In "Chinese characters and the left-brain vs. right-brain hypothesis " (1/7/16), we read about experimental results debunking " a myth that Chinese languages were predominantly processed by the right hemisphere, compared with alphabetic languages processed by the left hemisphere…."
Now, a team of scientists from Zaozhuang University, Beijing Normal University, and the University of Illinois have published the results of an experiment that offers additional evidence in favor of these findings:
Lijuan Zou, Jerome L. Packard, Zhichao Xia, Youyi Liu, and Hua Shu, "Neural Correlates of Morphological Processing: Evidence from Chinese", Front. Hum. Neurosci., 19 January 2016.
Morphological decomposition is an important part of complex word processing. In Chinese, this requires a comprehensive consideration of phonological, orthographic and morphemic information. The left inferior frontal gyrus (L-IFG) has been implicated in this process in alphabetic languages. However, it is unclear whether the neural mechanisms underlying morphological processing in alphabetic languages would be the same in Chinese, a logographic language. To investigate the neural basis of morphological processing in Chinese compound words, an fMRI experiment was conducted using an explicit auditory morphological judgment task. Results showed the L-IFG to be a core area in Chinese morphological processing, consistent with research in alphabetic languages. Additionally, a broad network consisting of the L-MTG, the bilateral STG and the L-FG that taps phonological, orthographic, and semantic information was found to be involved. These results provide evidence that the L-IFG plays an important role in morphological processing even in languages that are typologically different.
Once again, these experimental data confirm the conclusions summarized in William C. Hannas' 1997 book, Asia's Orthographic Dilemma (University of Hawaii Press), as tersely presented in this comment:
Isolated Chinese characters presented out of their linguistic context to subjects of experiments tend to be processed as images in the RH. In their linguistic context, e.g., paired with another character or followed by okurigana, they are processed in the LH, like any other language-related task.
All of these intelligently designed experiments come to similar conclusions (that Chinese languages are not substantially different from other languages in terms of the way they are processed in the brain) because they are focused on words rather than on parts of words or isolated glyphs. That is to say, they deal with natural languages, in which people speak and read in words, not smaller units out of their linguistic context.
J. M. Unger said,
January 27, 2016 @ 9:20 am
Zou et al. is an important study, but it does not support a simple left-brain/right-brain view. Although it shows that the left inferior frontal gyrus is as active in the morphological processing of Chinese as of "alphabetic languages" (the main conclusion), it also shows that the bilateral superior temporal gyri (both left and, notably also, right) were involved in concomitant tasks, such as the processing of "non-morphological phonological information."
See also G. Wayne Miller & Stephen Kosslyn, Top Brain, Bottom Brain (2013), which inter alia highlights the weaknesses of the left-brain / right-brain view in the popular literature.
Mark S said,
January 27, 2016 @ 1:34 pm
It is a fine study from a reliable lab but does not support the quoted claim that "isolated Chinese characters presented out of their linguistic context to subjects of experiments tend to be processed as images in the RH." Isolated characters elicit bilateral activation; I know of no study suggesting the LF is silent when characters are presented in isolation but lights up when presented in context, or that they are merely processed "as images". Note also that activation in L-IFG has many causes, one of which is task difficulty. Harder tasks, more activation, ceteris paribus. This complicates comparisons between languages/writing systems that are organized differently.
Jerry Packard said,
January 27, 2016 @ 1:57 pm
I think Jim and Mark are right in saying that the study doesn't provide strong left-right evidence for character orthography one way or the other. It's important to note that the stimuli in this experiment were spoken, auditorily perceived, words.