title: Cross-modal temporal order memory for auditory digits and visual locations: an fMRI study.
abstract: A function of working memory is to remember the temporal sequence of events, often occurring across different sensory modalities. To study the neural correlates of this function, we conducted an event-related functional magnetic resonance imaging (fMRI) experiment with a cross-modal memory task. Subjects were required to recall auditory digits and visual locations either in mixed order (cross-modality) or in separate order (within-modality). To identify the brain regions involved in the memory of cross-modal temporal order, we compared the blood oxygenation level-dependent (BOLD) response between the mixed and the separate order tasks. As a control, cortical areas sensitive to the memory load were mapped by comparing the 10-item condition with the 6-item condition in the separate order task. Results show that the bilateral prefrontal, right premotor, temporo-parietal junction (TPJ) and left superior parietal cortices had significantly more activation in the mixed task than in the separate task. Some of these areas were also sensitive to the memory load, whereas the right prefrontal cortex and TPJ were relatively more sensitive to the cross-modal order but not the memory load. Our study provides potential neural correlates for the episodic buffer, a key component of working memory as proposed previously [Baddeley. Trends Cogn Sci 2000;4:417-423].
authors.affiliation: Department of Neurobiology and Biophysics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China. drzhang@ustc.edu.cn
authors.forename: Daren
authors.initials: D
authors.lastname: Zhang
authors.forename: Xiaochu
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiwen
authors.initials: X
authors.lastname: Sun
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Li
authors.forename: Zhaoxin
authors.initials: Z
authors.lastname: Wang
authors.forename: Sheng
authors.initials: S
authors.lastname: He
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Hu
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D010775:Photic Stimulation