アイテム詳細

要旨

The Medial Temporal Lobe (MTL) is central to spatial navigation and to the processing of conceptual associations, functions which can be implemented via the grid cell system. Evidence exists that also hierarchical processing - an integral part of cognitive capacities such as language, motor action and sequential planning - draws on the MTL. This raises the question of whether hierarchical processing shares the same cellular substrate with spatial navigation and concept association formation. Here we present two novel tasks (hierarchy and control) specifically designed to test (using fMRI) whether grid cells also support the representation of hierarchical relations. We present the first results of their behavioral validation with respect to specificity, and show that our hierarchical task, but not the control task, correlates well with other tasks that necessitate hierarchical processing (Tower of Hanoi and a Visual Recursion Task). Furthermore, we show that some of these effects remain even when removing the shared variance that can be explained by a range of unspecific factors. This gives reason to believe that our task is a valid method for probing the relationship between grid cells and hierarchical processing.