A1 Refereed original research article in a scientific journal
Brain function during multi-trial learning in mild cognitive impairment: A PET activation study
Authors: Moulin CJA, Laine M, Rinne JO, Kaasinen V, Sipila H, Hiltunen J, Kangasmaki A
Publisher: ELSEVIER SCIENCE BV
Publication year: 2007
Journal: Brain Research
Journal name in source: BRAIN RESEARCH
Journal acronym: BRAIN RES
Volume: 1136
Issue: 1
First page : 132
Last page: 141
Number of pages: 10
ISSN: 0006-8993
DOI: https://doi.org/10.1016/j.brainres.2006.12.021
Abstract
We explored functional brain changes with positron emission tomography (PET) in mild cognitive impairment (MCI) patients and elderly normal controls by employing an episodic memory task that included two successive encoding trials of semantically related word-pairs and final retrieval. Both groups demonstrated significant learning across the two trials. The control group showed predominantly left frontal activity during encoding, and right frontal plus left temporal activity during retrieval. However, the MCI patients recruited partly different brain regions. They failed to activate right frontal and left temporal areas during retrieval, and failed to show any different activation for encoding on the first and second trials, whereas the controls activated a region of posterior cingulate. There was indication of compensatory increases in rCBF of the occipital cortex during incremental learning and the left frontal lobe during retrieval in the patients. These results suggest different episodic memory processing in the MCI group, and a possible over-reliance on semantic processing. Subtle functional changes occur in the pre-Alzheimer brain before there are marked structural or behavioural abnormalities. (c) 2006 Elsevier B.V. All rights reserved.
We explored functional brain changes with positron emission tomography (PET) in mild cognitive impairment (MCI) patients and elderly normal controls by employing an episodic memory task that included two successive encoding trials of semantically related word-pairs and final retrieval. Both groups demonstrated significant learning across the two trials. The control group showed predominantly left frontal activity during encoding, and right frontal plus left temporal activity during retrieval. However, the MCI patients recruited partly different brain regions. They failed to activate right frontal and left temporal areas during retrieval, and failed to show any different activation for encoding on the first and second trials, whereas the controls activated a region of posterior cingulate. There was indication of compensatory increases in rCBF of the occipital cortex during incremental learning and the left frontal lobe during retrieval in the patients. These results suggest different episodic memory processing in the MCI group, and a possible over-reliance on semantic processing. Subtle functional changes occur in the pre-Alzheimer brain before there are marked structural or behavioural abnormalities. (c) 2006 Elsevier B.V. All rights reserved.