TY - JOUR
T1 - Regional activation of the human medial temporal lobe during intentional encoding of objects and positions
AU - Ramsoy, Thomas Z.
AU - Liptrot, Matthew George
AU - Skimminge, Arnold Jesper Møller
AU - Lund, Torben E.
AU - Sidaros, Karam
AU - Christensen, Mark Schram
AU - Baare, William
AU - Paulson, Olaf B.
AU - Jernigan, Terry
PY - 2009
Y1 - 2009
N2 - The medial temporal lobe (MTL) consists of several regions thought to be involved in learning and memory. However, the degree of functional specialization among these regions remains unclear. Previous studies have demonstrated effects of both content and processing stage, but findings have been inconsistent. In particular, studies have suggested that the perirhinal cortex is more involved in object processing than spatial processing, while other regions such as the parahippocampal cortex have been implicated in spatial processing. In this Study, functional magnetic resonance imaging (fMRI) optimized for the MTL region was used to probe MTL activation during intentional encoding of object identities or positions. A region of interest analysis showed that object encoding evoked stronger activation than position encoding in bilateral perirhinal cortex, temporopolar cortex, parahippocampal cortex, hippocampus and amygdala. Results also indicate an unexpected significant Correlation in activation level between anterior and posterior portions in both the left parahippocampal cortex and left hippocampus. Exploratory analysis did not show any regional content effects during preparation and rehearsal stages. These results provide additional evidence for functional specialization within the MTL, but were less clear regarding the specific nature of content specificity in these regions. (C) 2009 Elsevier Inc. All rights reserved.
AB - The medial temporal lobe (MTL) consists of several regions thought to be involved in learning and memory. However, the degree of functional specialization among these regions remains unclear. Previous studies have demonstrated effects of both content and processing stage, but findings have been inconsistent. In particular, studies have suggested that the perirhinal cortex is more involved in object processing than spatial processing, while other regions such as the parahippocampal cortex have been implicated in spatial processing. In this Study, functional magnetic resonance imaging (fMRI) optimized for the MTL region was used to probe MTL activation during intentional encoding of object identities or positions. A region of interest analysis showed that object encoding evoked stronger activation than position encoding in bilateral perirhinal cortex, temporopolar cortex, parahippocampal cortex, hippocampus and amygdala. Results also indicate an unexpected significant Correlation in activation level between anterior and posterior portions in both the left parahippocampal cortex and left hippocampus. Exploratory analysis did not show any regional content effects during preparation and rehearsal stages. These results provide additional evidence for functional specialization within the MTL, but were less clear regarding the specific nature of content specificity in these regions. (C) 2009 Elsevier Inc. All rights reserved.
U2 - 10.1016/j.neuroimage.2009.03.082
DO - 10.1016/j.neuroimage.2009.03.082
M3 - Journal article
SN - 1053-8119
VL - 47
SP - 1863
EP - 1872
JO - NeuroImage
JF - NeuroImage
IS - 4
ER -