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Memory processing during encoding and retrieval of words revealed by fMRI
NemoImage 13, Number 6, 2001, Part 2 of 2 Parts ID E C;L@
MEMORY
Memory ProcessingDuring Encoding and Retrieval of Words Revealedby fMRI. BA Verchinski, B Elvevaag, TE Goldberg, VS Mattay, P Weissbrod, R Coppola, JH Callicott, Daniel Weinberger Clinical Brain Disorders Branch, National Institutes of Health, Bethesda, MD 20892-1389, U.S.A. Introduction: The ability to retrieve explicit verbal memories is related to the depth of cognitive processing required while a word is being encoded. Previous brain imaging studies have suggested specific left frontal regions contributing to verbal encoding while other studies have found the right prefrontal cortex and hippocampal formation to be active during retrieval conditions. No previous study has looked at both encoding and retrieval in the same imaging context. Methods: We studied 9 right-handed normal subjects (5 female, 4 male). Our deep encoding task consisted of word presentations in which subjects identified items as living or non-living objects, our shallow encoding task consisted of word presentations in which subjects had to identify whether or not the presented word contained the letter “a.” In the retrieval conditions, subjects had to correctly identify whether or not they had previously seen the word. Presentation was in block format such that words from the deep encoding condition were presented in one run, and words from shallow encoding condition were presented in another run. In both retrieval runs, fifty percent of the words had previously been presented and 50% were new (i.e., foils). Data were collected on a 1.5T GE scanner using a whole brain fast single-shot spiral acquisition (TB=2OOOms, TE=24ms, 240mm FOV, 36 slices, 3.75 cubic voxels). The functional images were normalized to a standard Talairach template and smoothed with a 10 mm isotropic Gaussian kernel. Data were then analyzed using Statistical Parametric Mapping (SPM99). Results: Behavioral dam revealed a significantly greater percentage of correct responses to the deep versus the shallow retrieval task (pc.05). Brain activation during deep encoding was greater than that of shallow encoding in the superior temporal gyms bilaterally (Brodmann area [BA] 22 (-44 2 -3) p<.OO4) and BA 38 (48 11 -7) p<.O2)), the inferior frontal gyms bilaterally (BA 44 (-40 13 20) p-C.01 and BA 44/45 (48 18 -18) p<.OO3) and in the left middle frontal gyms (BA 46 (40 41 5) p
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MEMORY
Memory ProcessingDuring Encoding and Retrieval of Words Revealedby fMRI. BA Verchinski, B Elvevaag, TE Goldberg, VS Mattay, P Weissbrod, R Coppola, JH Callicott, Daniel Weinberger Clinical Brain Disorders Branch, National Institutes of Health, Bethesda, MD 20892-1389, U.S.A. Introduction: The ability to retrieve explicit verbal memories is related to the depth of cognitive processing required while a word is being encoded. Previous brain imaging studies have suggested specific left frontal regions contributing to verbal encoding while other studies have found the right prefrontal cortex and hippocampal formation to be active during retrieval conditions. No previous study has looked at both encoding and retrieval in the same imaging context. Methods: We studied 9 right-handed normal subjects (5 female, 4 male). Our deep encoding task consisted of word presentations in which subjects identified items as living or non-living objects, our shallow encoding task consisted of word presentations in which subjects had to identify whether or not the presented word contained the letter “a.” In the retrieval conditions, subjects had to correctly identify whether or not they had previously seen the word. Presentation was in block format such that words from the deep encoding condition were presented in one run, and words from shallow encoding condition were presented in another run. In both retrieval runs, fifty percent of the words had previously been presented and 50% were new (i.e., foils). Data were collected on a 1.5T GE scanner using a whole brain fast single-shot spiral acquisition (TB=2OOOms, TE=24ms, 240mm FOV, 36 slices, 3.75 cubic voxels). The functional images were normalized to a standard Talairach template and smoothed with a 10 mm isotropic Gaussian kernel. Data were then analyzed using Statistical Parametric Mapping (SPM99). Results: Behavioral dam revealed a significantly greater percentage of correct responses to the deep versus the shallow retrieval task (pc.05). Brain activation during deep encoding was greater than that of shallow encoding in the superior temporal gyms bilaterally (Brodmann area [BA] 22 (-44 2 -3) p<.OO4) and BA 38 (48 11 -7) p<.O2)), the inferior frontal gyms bilaterally (BA 44 (-40 13 20) p-C.01 and BA 44/45 (48 18 -18) p<.OO3) and in the left middle frontal gyms (BA 46 (40 41 5) p
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