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Brain activation during autobiographical memory retrieval with special reference to default mode network.

Ino T, Nakai R, Azuma T, Kimura T, Fukuyama H - Open Neuroimag J (2011)

Bottom Line: We delineated the overlap between the regions that showed less activation during semantic memory and number counting relative to rest, which correspond to the DMN, and the areas that showed greater or less activation during ABM relative to rest.ABM-specific activation was defined as the overlap between the contrast of ABM versus rest and the contrast of ABM versus semantic memory.ABM-specific activation was observed in the left-lateralized brain regions and most of them fell within the DMN.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Rakuwakai-Otowa Hospital, Otowachinjicho 2, Yamashina-ku, Kyoto 607-8062, Japan.

ABSTRACT
Recent neuroimaging studies have suggested that brain regions activated during retrieval of autobiographical memory (ABM) overlap with the default mode network (DMN), which shows greater activation during rest than cognitively demanding tasks and is considered to be involved in self-referential processing. However, detailed overlap and segregation between ABM and DMN remain unclear. This fMRI study focuses first on revealing components of the DMN which are related to ABM and those which are unrelated to ABM, and second on extracting the neural bases which are specifically devoted to ABM. Brain activities relative to rest during three tasks matched in task difficulty assessed by reaction time were investigated by fMRI; category cued recall from ABM, category cued recall from semantic memory, and number counting task. We delineated the overlap between the regions that showed less activation during semantic memory and number counting relative to rest, which correspond to the DMN, and the areas that showed greater or less activation during ABM relative to rest. ABM-specific activation was defined as the overlap between the contrast of ABM versus rest and the contrast of ABM versus semantic memory. The fMRI results showed that greater activation as well as less activation during ABM relative to rest overlapped considerably with the DMN, indicating that the DMN is segregated to the regions which are functionally related to ABM and the regions which are unrelated to ABM. ABM-specific activation was observed in the left-lateralized brain regions and most of them fell within the DMN.

No MeSH data available.


The contrast effect of each task condition (ABM, SEM, and NC) compared to REST in the local maxima for the overlap between AMB > REST and ABM > SEM, which correspond to the intersection of lines in the lower panels. Bars represent the limit of the 90% confidence interval around the mean. DPM, dorsal premotor area; IPL, inferior parietal lobule; MTG, middle temporal gyrus; RS, retrosplenial cortex; PCG, posterior cingulate gyrus; and VMPFC, ventro-medial prefrontal cortex.
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Figure 5: The contrast effect of each task condition (ABM, SEM, and NC) compared to REST in the local maxima for the overlap between AMB > REST and ABM > SEM, which correspond to the intersection of lines in the lower panels. Bars represent the limit of the 90% confidence interval around the mean. DPM, dorsal premotor area; IPL, inferior parietal lobule; MTG, middle temporal gyrus; RS, retrosplenial cortex; PCG, posterior cingulate gyrus; and VMPFC, ventro-medial prefrontal cortex.

Mentions: ABM-specific activation, which was defined as the overlap between the contrast of ABM vs. rest and the contrast of ABM vs. semantic memory, was found in the left-lateralized brain regions including posterior cingulate gyrus/retrosplenial cortex, dorsal premotor area, ventromedial PFC, precentral gyrus, inferior parietal lobule, middle temporal gyrus, superior temporal gyrus, and frontopolar cortex (Fig. 4, Table 3). All of them except dorsal premotor area and middle temporal gyrus fell within the areas that showed less activation during number counting (compare Fig. 3 and Fig. 4). Contrast effect across conditions (ABM, semantic memory, and number counting) at the voxel of peak activation is shown in Fig. (5). All of the ABM-specific activation except for dorsal premotor area and middle temporal gyrus showed large negative contrast effect during number counting, suggesting that most of the ABM-specific activation were located within the DMN.


Brain activation during autobiographical memory retrieval with special reference to default mode network.

Ino T, Nakai R, Azuma T, Kimura T, Fukuyama H - Open Neuroimag J (2011)

The contrast effect of each task condition (ABM, SEM, and NC) compared to REST in the local maxima for the overlap between AMB > REST and ABM > SEM, which correspond to the intersection of lines in the lower panels. Bars represent the limit of the 90% confidence interval around the mean. DPM, dorsal premotor area; IPL, inferior parietal lobule; MTG, middle temporal gyrus; RS, retrosplenial cortex; PCG, posterior cingulate gyrus; and VMPFC, ventro-medial prefrontal cortex.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3106359&req=5

Figure 5: The contrast effect of each task condition (ABM, SEM, and NC) compared to REST in the local maxima for the overlap between AMB > REST and ABM > SEM, which correspond to the intersection of lines in the lower panels. Bars represent the limit of the 90% confidence interval around the mean. DPM, dorsal premotor area; IPL, inferior parietal lobule; MTG, middle temporal gyrus; RS, retrosplenial cortex; PCG, posterior cingulate gyrus; and VMPFC, ventro-medial prefrontal cortex.
Mentions: ABM-specific activation, which was defined as the overlap between the contrast of ABM vs. rest and the contrast of ABM vs. semantic memory, was found in the left-lateralized brain regions including posterior cingulate gyrus/retrosplenial cortex, dorsal premotor area, ventromedial PFC, precentral gyrus, inferior parietal lobule, middle temporal gyrus, superior temporal gyrus, and frontopolar cortex (Fig. 4, Table 3). All of them except dorsal premotor area and middle temporal gyrus fell within the areas that showed less activation during number counting (compare Fig. 3 and Fig. 4). Contrast effect across conditions (ABM, semantic memory, and number counting) at the voxel of peak activation is shown in Fig. (5). All of the ABM-specific activation except for dorsal premotor area and middle temporal gyrus showed large negative contrast effect during number counting, suggesting that most of the ABM-specific activation were located within the DMN.

Bottom Line: We delineated the overlap between the regions that showed less activation during semantic memory and number counting relative to rest, which correspond to the DMN, and the areas that showed greater or less activation during ABM relative to rest.ABM-specific activation was defined as the overlap between the contrast of ABM versus rest and the contrast of ABM versus semantic memory.ABM-specific activation was observed in the left-lateralized brain regions and most of them fell within the DMN.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Rakuwakai-Otowa Hospital, Otowachinjicho 2, Yamashina-ku, Kyoto 607-8062, Japan.

ABSTRACT
Recent neuroimaging studies have suggested that brain regions activated during retrieval of autobiographical memory (ABM) overlap with the default mode network (DMN), which shows greater activation during rest than cognitively demanding tasks and is considered to be involved in self-referential processing. However, detailed overlap and segregation between ABM and DMN remain unclear. This fMRI study focuses first on revealing components of the DMN which are related to ABM and those which are unrelated to ABM, and second on extracting the neural bases which are specifically devoted to ABM. Brain activities relative to rest during three tasks matched in task difficulty assessed by reaction time were investigated by fMRI; category cued recall from ABM, category cued recall from semantic memory, and number counting task. We delineated the overlap between the regions that showed less activation during semantic memory and number counting relative to rest, which correspond to the DMN, and the areas that showed greater or less activation during ABM relative to rest. ABM-specific activation was defined as the overlap between the contrast of ABM versus rest and the contrast of ABM versus semantic memory. The fMRI results showed that greater activation as well as less activation during ABM relative to rest overlapped considerably with the DMN, indicating that the DMN is segregated to the regions which are functionally related to ABM and the regions which are unrelated to ABM. ABM-specific activation was observed in the left-lateralized brain regions and most of them fell within the DMN.

No MeSH data available.