Functional MRI study on word association of language expression in the normal middle-aged and old people

Abstract

Objective To detect brain areas related to word association of language expression and to summarize the characteristics of the active areas in the normal middle-aged and old subjects with function magnetic resonance imaging (fMRI). Methods Twenty-three middle-aged and old subjects were recruited in this study. All of them received block-designed fMRI with word association of language expression. GE 1.5 T Twin speed MR Scanner was used to obtain fMRI data. SPM 2 software was used to process fMRI data and to get the average activation maps. Location and activation degree were observed and recorded. Results Twelve subjects were admitted into the study. Activated regions included bilateral premotor cortex (PMC), bilateral posterior inferior frontal gyrus (Broca's area and Broca's mirror image), bilateral supplemental motor area (SMA), left posterior parietal cortex, bilateral insular lobe, bilateral anterior callosal gyrus, bilateral basal ganglions, left thalamus, and right cerebellum. Left PMC was the most activated area of whole brain. Left Broca's area, left dorsal PMC and SMA were more activated than corresponding contralateral areas. Right ventral PMC, insular lobe, anterior eallosal gyrus and basal ganglions were more activated than corresponding contralateral areas. Conclusions There are many brain areas associated with motor language expression function in the middle-aged and old people. A complex neural network is made up of the areas including Broca's area. Lateralization of the language expression areas presents in left hemisphere and right cerebellum prominence. Key words: Magnetic resonance imaging; Language tests; Aphasia; Middle-aged and old people; Activation