Contribution of the rostral part of the left temporal lobe to retrieving people's names: A functional MRI study

Neurohnage

11, Number

5, 2000,

Part 2 of 2 Parts 10

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MEMORY

Contribution

- LEARNING

of the Rostra1 Part of the Left Temporal Lobe to Retrieving People’s Names: A Functional MRI Study

Takashi Tsukiura*t, Toshikatsu Fujii *, Jiro Okuda*f, Michio Tabuchi*, Kengo Kurata*, Kyoko Suzuki*, Atsushi UmetsuS, Ryuta Kawashima’, Isao Yanagawag, Tatsuo Nagasakas, Atsushi Yamadori*, Shoki Takahashi$, Hiroshi FukudaP *Section of Neuropsychology, Tohoku University Graduate School of Medicine, Sendai, Japan tThe Japan Society for the Promotion of Science, Tokyo, Japan *Department

of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan

#Division oj Radiology, Tohoku University Hospital, Sendai, Japan ‘Institute of Development, Aging & Cancer, Tohoh We previously reported a patient with left temporal lobectomy, preserved retrieval of common names or knowledge of people (1). people’s names has also been demonstrated in PET studies (2,3). neuroanatomical bases of retrieval of people’s names, and (b) to familiar and newly learned people’s names.

who showed The role of the The purposes elucidate the

University, Sendai, Japan impaired retrieval of people’s names along with rostra1 part of the left temporal lobe in retrieving of the present fMR1 study are (a) to identify the different activation patterns between retrieval of

Methods Five right-handed healthy young men participated in this study. Before scanning, the subjects memorized 20 photographs of novel faces associated with their family names and their occupation names. These 20 photographs were divided into two sets, each consisting of 10 photographs (set 1 and 2). Set 3 and 4 consisted of 10 photographs of famous people. Four experimental tasks were used: retrieval of names of novel people from set 1 (NN), retrieval of famous people’s names from set 3 (FN), retrieval of novel people’s occupation from set 2 (NO), and retrieval of famous people’s occupation from set 4 (FO). During scanning, a sequential box-car design was employed. One session consisted of two tasks selected from four tasks mentioned above, which were alternatively presented three times during one session. Each stimulus was presented one by one at a rate of 4 seconds. The subjects participated in four sessions: NN and NO in the first session, FN and FO in the second session, NN and FN in the third session, and NO and FO in the fourth session. After scanning, we assessed the performance of the subjects in four retrieval tasks. All MRI studies were carried out by gradient echo EPI implemented by Siemens Magnetom Vision (1.5T). The parameters for EPI were as follows: TR/ TE=4000/ 66 (ms). flip angle=90 degrees. Acquired data points for analyses in one session were sixty. All data were analyzed by two-way ANOVA with SPM96 and thresholded at p7 voxels). ReSUltS First, we identified the significant main effect of category (people’s names minus occupation names) in the left superior frontal (BAlO: x=-21, y=63, z=24), anterior cingulate (BA32: -4, 28, 30) posterior cingulate (BA31: -4, 28, 30), superior temporal (BA38: -52, 24, -18) gyri, striate cortex (BA17: -14, -105, 6), and cuneus (BA18: -10, -98, 18, and BA19: -7. -77, 36). Subsequently, we detected significant activated areas related to retrieval of familiar people’s names in comparison with occupation name in the left superior temporal (BA38: -49. 21, -18) and the medial frontal gyms (BA32: 0, 14, 36). Furthermore, in comparing name retrieval with occupation name retrieval of newly learned people, additional significant activations to the left anterior superior temporal gyms (BA38: -60, 14, -18) were identified in some regions such as the bilateral prefrontal area, left superior parietal lobule. Second. the analysis for the main effect of familiarity (newly Icarned minus familiar) demonstrated the significant activation of the left middle frontal (BA6: -46. 14, 54; BAI I: -24. 32. -18: BA46: -52. 42, IX). the right inferior frontal (BAIO: 42. 52, O), precentral (BA6: 66, 0. 12) gyri, precuneus (BA7: 7. -74, 42), and posterior cingulate gyrus (BA31: 0, -28, 30). Retrieval of newly learned name as compared with familiar people‘s n‘nne >hc~ued the ~nidiuonal Ggnitiidnt acti\-ities to the nnhn effect uf fanuharir) in regions such as the left superior parietal, right middle frontal, and right superior temporal lobes. Discussion Significant activities of the left superior temporal gyms (HA 3X) were detected in all contrasts between people’s and occupation names. This finding indicates that the rostral part of the left temporal lobe may be more responsible for retrieving people’s names than common names such as occupation, regardless of the retention interval. In retrieving newly learned people’s names compared with retrieving familiar names. bilateral prefrontal, posterior cingulate and left parietal areas were activated. This suggests that broader neural networks are necessary for retrieving newly learned people’s names and roles of these areas for retrieving people’s names may decrease with the course of time. References 1. Fukatsu, R.. Fujii, T., Tsukiura, T., Yamadori, A., & Otsuki, T. Neurology, 1999, 52, 1096-1099. 2. Damasio. H., Grabowski, T. J., Tranel, D., Hichwa, R. D.. & Damasio, A. R. Nature. 1996, 380, 499-505. 3. Gomo-Tempini, M. L., Price, C. J.. Josephs, O., Vandenberghe, R.. Cappa, S. F., Kapur. N., & Frackowiak, 121. 2103-18.

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