TY - JOUR T1 - Neural correlate of verbal episodic memory: Encoding, retrieval, and retrieval strategy JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 241P LP - 241P VL - 48 IS - supplement 2 AU - Eun Jin Yoon AU - Sang Soo Cho AU - Seong Ae Bang AU - Hyun Soo Park AU - Yu Kyeong Kim AU - Won Woo Lee AU - Sang Eun Kim Y1 - 2007/05/01 UR - http://jnm.snmjournals.org/content/48/supplement_2/241P.3.abstract N2 - 1125 Objectives: Episodic memory is not a mere single process rather complicated processes including several components. To understand neuronal mechanisms of verbal episodic memory, we investigated neural substrates related to the three primary episodic memory components: encoding, retrieval, and retrieval strategy. For this purpose, we used FDG PET and a voxel-wise correlation analysis. Methods: Twenty-eight right-handed healthy subjects (mean age, 25 ± 3 y; 15 males/13 females) were studied with FDG PET during a resting state. In all subjects, three subscores of Hopkins Verbal Learning Test (HVLT) were obtained to characterize their verbal episodic memory components: total free recall (encoding), delayed free recall (retrieval), and recognition enhancement (retrieval strategy). Specific correlations between regional glucose metabolism and HVLT subscores were examined using SPM2 (P < 0.03 uncorrected, k=100). Results: The encoding score showed a significant correlation with glucose metabolism in the bilateral fusiform gyri, hippocampus and cerebellum and right inferior temporal gyrus, regions that play a role in imagery process of verbal information and form the semantic associations between words. The retrieval score had a correlation with metabolism in the bilateral dorsolateral prefrontal cortex and left posterior cingulate gyrus, regions that are involved in retrieval mode and visual mnemonic processes. The retrieval strategy score showed a correlation with metabolism in the bilateral orbitofrontal cortex and left anterior cingulate gyrus, areas associated with retrieval attempt and decision processes. Conclusions: These results suggest that brain regions involved in semantic and visual processing may work as primary neural substrate for successful encoding and retrieval of memory, while the neural system associated with decision making plays a critical role in retrieval strategy of episodic memory processes. ER -