Role of medial temporal lobe in working and episodic memory during encoding
- López García, María Eugenia 2
- Campo, Pablo 4
- García Morales, Irene
- Gil Nagel, Antonio 1
- Pozo Guerrero, Francisco del 3
- Maestú, Fernando 2
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1
Hospital Ruber Internacional
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2
Universidad Complutense de Madrid
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3
Universidad Politécnica de Madrid
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4
Universidad Autónoma de Madrid
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Editorial: Nova Science Publishers
ISBN: 9781619421882
Año de publicación: 2012
Páginas: 119 - 140
Tipo: Capítulo de Libro
Resumen
Hithertothelong-term memory (LTM)and the working memory (WM) have beenconsidered two completely separate processes because they have been associated with different brain structures (the temporal lobe and prefrontal and parietal areas, respectively). However, recent neuroimaging studies show that the medial temporal lobe (MTL) is involved in WM. The main objective of this study is to investigate the contribution of the MTL in two verbal tasks, one of WM and the other one of LTM, during the encoding. We compare the activity of this structure using the magnetoencephalography (MEG) to analyse brain spatio- temporal profiles of memory success in 9 patients with left hippocampal sclerosis (HS) and 8 healthy matched controls. The performance in the control group is higher in the WM task than in the LTM one, being similar in both conditions in the patient group. The controls show a greater number of dipoles during the LTM task compared with the WM one, mainly in the 200 to 400ms after the stimulus presentation, no founding significant differencesbetween thetwohemispheres. In the patients group, there are no differences between conditions in activity but in both of them the right hemisphere is more activated, essentially between 500 and 600ms. These findings provide clear evidence that the MTL is essential for the LTM, but also that it contributes in the verbal WM encoding.