Poster A48, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
Sequence processing and language lateralization
Shuang Geng1, Qi Su1, Shuai Wang1, Xing Tian2,3, Qing Cai1,3; 1School of Psychology and Cognitive Science, East China Normal University, 2New York University Shanghai, 3NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai
Sequence processing plays an important and irreplaceable role in language perception and production. However its origin and mechanism are not yet clear. Here, we asked three questions: (1) Whether two hemispheres contribute to sequence processing distinctively, and how two kinds of sequencing (the planning of sequencing and the execution of sequencing) influence lateralization differently? (2) Whether motor-sensory processing is left dominant or bilateral in language and sequence processing? 3) Whether sequence processing is specific to language processing? In this study, we investigated the neural mechanism of sequence processing of syllable, tone, and finger movement sequences using functional MRI. Our results showed that (1) the planning of sequencing in a syllable task is strongly left dominant in the inferior frontal gyrus and superior parietal area, whereas the execution of sequencing in this task is not significantly left lateralized; (2) the sensory-motor (or perception-production) interaction during syllable sequencing and tone sequencing are different: bilateral middle frontal gyrus is involved in syllable sequencing; whereas a set of frontal regions in the right hemisphere underlies sensory-motor processing during tone sequencing; (3) execution of sequencing are further examined in three tasks: middle frontal gyrus and tempo-parietal junction are activated in tone sequencing; inferior frontal cortex is involved in motor sequencing when using right hand; left frontal and parietal regions are involved in syllable sequencing, but only in the imagery condition. Our results suggest that processing dynamics, modality and content of tasks modulated the hemispherical lateralization during sequencing in speech and language.
Topic Area: LANGUAGE: Other