Open AccessAssociative encoding of pictures activates the medial temporal lobes
Author(s) -
Montaldi Daniela,
Mayes Andrew R.,
Barnes Anna,
Pirie Heather,
Hadley Donald M.,
Patterson Jim,
Wyper David J.
Publication year - 1998
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/(sici)1097-0193(1998)6:2<85::aid-hbm2>3.0.co;2-g
Subject(s) - posterior cingulate , temporal lobe , neuroscience , hippocampal formation , psychology , statistical parametric mapping , parahippocampal gyrus , region of interest , novelty , temporal cortex , cortex (anatomy) , computer science , artificial intelligence , medicine , magnetic resonance imaging , epilepsy , social psychology , radiology
It remains unresolved whether the medial temporal lobe activations found in recent neuroimaging studies are mediated by novelty detection alone, by specific kinds of encoding or consolidation operations, or both. This study attempted to see whether associative encoding or consolidation is sufficient to cause such activation by matching for novelty across conditions. Using single‐photon emission computer tomography (SPECT) (with Tc 99m HMPAO), we compared the activation patterns produced by the associative encoding and the perceptual matching of novel complex scenes in 10 normal subjects using both statistical parametric mapping (SPM) and a regions‐of‐interest (ROI) approach. During the encoding condition, significant activations were detected in the left hippocampal/parahippocampal region, the left cingulate cortex, and the right prefrontal cortex, using both statistical techniques. Additionally, activation was found in the right cingulate cortex, and a trend towards activation was found in the right hippocampal/parahippocampal region using the ROI approach. In contrast, no medial temporal activations were found during the matching condition, which produced bilateral occipito‐parietal and right posterior inferior parietal (supramarginal gyrus) activations. These results not only confirm that the associative encoding and/or consolidation of complex scenes is partially mediated by medial temporal lobe structures, but also demonstrate, for the first time, that associative encoding/consolidation is sufficient to produce such an activation. The implications of the high degree of consistency revealed by the results of the SPM and ROI comparison are discussed. Hum. Brain Mapping 6:85–104, 1998. © 1998 Wiley‐Liss, Inc.