Tone is the subject of intensive study in the field of cognitive research on Chinese characters in recent years. This thesis first describes characteristics of Chinese characters especially oftone and related behavioral studies, and then reviews recent studies on tonal ear advantage, tonal process of brain damaged patients, and tonal research with functional magnetic resonance imaging(fMRI), which tested tonal process theories. On the basis of this review, we conducted the following study.
Object: to investigate behavioral characteristics and activation of Chinese character tone processing, by use of behavioral test and functional magnetic resonance imaging.
Methods: 30 participants were asked to name visually presented Chinese characters and reaction time for each stimulus was recorded. According to the consistency of the pronunciation and tone between phonetic radicals and whole characters, the stimulation materials were grouped into four types: pronunciation-same-tone-same character,pronunciation-same-tone-difference character, pronunciation-difference-tone-same character and pronunciation-difference-tone-difference character. There were 20 characters for each stimulus type. Another 13 participants were scanned with a 1.5 T MRI scanner while performing the same tasks.
The behavioral study showed that the main effect of pronunciation was significant while that of tone was not. The fMRI experiment indicated that all four types of stimuli activated bilateral middle frontal gyrus, inferior frontal gyrus, premotor cortex supplementary motor area, superior temperal gyrus and left fusiform. A few regions, such as medial frontal gyrus and middle temperal gyrus, were activated in only some types of stimuli. There were differences in brain lateralization across four different conditions.This experiment also characterized the activation patterns, i.e., time course of activation,in right superior temperal gyrus. bilateral inferior frontal gyrus, and other regions.
Based on the above results, we conclude:
1.Comparing to traditional studies usually with auditory modality, visual modality provides a novel approach to understand tonal processing.
2.The finding of semi-regularity effect in Chinese characters processing associated with tone processing suggests that the impact of tone on process should take into account.
3.Tone effect cannot be effectively identified by reaction time, but can be recorded by fMRI used in the present study.
4.There is hemispheric laterality in the process of Chinese characters, including tone processing.