Encoding and Retrieval of Words and Scenes Assessed by Functional MRI in Normal Right-Handed Volunteers / 대한간질학회지

ABSTRACT

PURPOSE: To find the activation patterns of frontal and medial temporal lobe during memory tasks (encoding and retrieval) with novel stimuli (words, scenes) in normal right-handed volunteers. Another aim is to examine which memory paradigms and processes are effective to activate medial temporal lobe. METHODS: We included 10 right-handed normal volunteers. Stimuli consisted of encoding and retrieval of novel word (15 items)/novel scenes (15 items). During scanning, each stimulus was presented for 2000 ms. Imaging was performed on 1.5 GE scanner. Group analysis was performed in volunteers with SPM 2 (uncorrected p10). RESULTS: Scenes encoding and retrieval activated both medial temporal lobes, more on the right side. Word encoding activated predominantly dominant frontal lobe, but failed to activate the medial temporal lobes. The word stimuli activated more the frontal lobe than the picture stimuli. Retrieval process activated more the medial temporal lobe than encoding process. CONCLUSION: Our results showed that the scenes encoding/retrieval and word retrieval are useful to activate the medial temporal lobe and word encoding is useful for activating dominant frontal lobe. Further studies will be necessary in patient groups with unilateral temporal lobe lesion to document the usefulness of this study.