Hippocampal formation, its subdivisions and specific contributions to the visuospatial memory

Abstract

Memory is a cognitive function that can be defined as the capacity to recognize, to retain, to fix and to evoke certain contents and past experiences. It is extremely important for humans, and depends directly on the functioning of the hippocampal formation, a brain structure localized in the medial portion of the temporal cortex, formed by subregions, as the hippocampus, the dentate gyrus and the subiculum. The present study aims to investigate, in an original manner, if there is an association between the hippocampal formation volume, including its subdivisions, and the performance in visuospatial memory tasks. To accomplish this, a sample of 30 healthy individuals will be evaluated by means of the following measures: the Rey-Osterrieth Complex Figure Test and three computerized memory tests pertaining to the Cambridge Neuropsychological Test Automated Battery (CANTAB). The analyses of the tests results will be combined with the analyses of the structural magnetic resonance images (MRI) in order to verify a possible relationship between the two variables (visuospatial memory and imaging). The analysis of the MRI data will be performed with the segmentation of the hippocampal formation by means of the Freesurfer software, version 6.0. Our hypothesis is that there will be a direct association between the hippocampal formation volume and the performance in the memory tasks, where a greater volume will correspond to a better performance in the visuospatial memory tests. In addition, according to the available evidence revised for this study, we will also test the hypothesis that the association between the hippocampal formation and the performance in the memory tests will be more pronounced in the right than the left hemisphere. (AU)