Disambiguating the Role of the Retrosplenial Complex in Human Navigation
Date
2018-06-14
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Abstract
The role of the human retrosplenial cortex in spatial orientation and navigation has been obscured by a long history of ambiguous localization, beginning as early as Brodmann’s original depiction which intentionally overrepresented it’s extent. While some modern atlases of the brain exclude this region, many include a surprisingly generous delineation; this has resulted in a very large area of the medial parietal cortex implicitly viewed as being equipotentially involved in spatial orientation and navigation. In this thesis, I provide novel evidence of a more precise paradigm by which we can understand the role of the ‘retrosplenial cortex’, i.e. the posterior cingulate, in spatial orientation and navigation. First, from fMRI activity evoked in a novel spatial task, but subsequently from a meta-analysis of the literature more generally, we have identified that ventral portions of the posterior cingulate are relatively more engaged in encoding spatial information, whereas dorsal portions are more involved in recalling and computing spatial information or representations. Not simply descriptive, this delineation proved valuable in characterizing the neural correlates of a lifelong developmental condition in which individuals get lost on a daily basis in very familiar surroundings, a condition known as Developmental Topographical Disorientation (DTD). In fact, we identified that the dorsal posterior cingulate displays far greater differences then the ventral posterior cingulate in functional connectivity between individuals with DTD and healthy controls; these findings would not have been uncovered with traditional delineations of the retrosplenial cortex. Other studies will undoubtedly benefit from appreciating these functional subregions when analyzing or interpreting activity within the posterior cingulate evoked by spatial orientation tasks. A clear understanding of the neural correlates of spatial orientation and navigation in humans will benefit greatly from future research validating this posterior cingulate delineation, as well as extending increasingly meticulous attention to the location of activity evoked in the posterior cingulate and other brain regions.
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Keywords
Spatial Orientation, Posterior Cingulate, Getting Lost, Developmental Topographical Disorientation, fMRI
Citation
Burles, C. F. (2018). Disambiguating the Role of the Retrosplenial Complex in Human Navigation (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/32007