When You Can’t Make Make Mental Maps: Developmental Topographical Disorientation

Developmental Topographical Disorientation is a rare neurological condition that prevents people from creating mental maps of their surroundings and impairs navigation. Researchers estimate about 1-2% of people are affected by DTD, but research on the disorder is relatively new and case studies are scarce. The first paper on DTD was published in 2008 and research in the following years has made leaps and bounds in the field.

DTD affects the way people create cognitive maps and can seriously hinder peoples’ ability to navigate. Using maps, a GPS or landmarks can help, but frequently simple journeys can take much longer. People with DTD liken the disorder to being a perpetual tourist- never quite knowing where they are.

A neuroscientist at the University of Calgary named Giuseppe Iaria published a paper in 2008 about DTD and has been instrumental in further understanding of the disorder. The people he has studied do not show signs of brain damage, adverse neurological conditions, or any other factors that make them different from normal people. Their brains seem to function just like anyone else’s.

Map showing in red the route a patient with DTD was supposed to follow and in blue the route he actually took.  Source: Bianchini et al, 2013.

Map showing in red the route a patient with DTD was supposed to follow and in blue the route he actually took. Source: Bianchini et al, 2013.

However, the ways in which the brains of people with DTD function is drastically different than that of a normal person. Using MRI scans and other sensitive brain imaging technologies, Iaria and other researchers are discovering just what makes the brains of DTD patients unique. They found that the brain scans of resting DTD patients showed decreased communication between the hippocampus and prefrontal cortexes, both locations vital to spatial orientation. The two areas of the brain don’t work in sync with one another which impairs navigational abilities.

Not only does this information shed light on the specifics of DTD, but on neuroscience in general. For many years neuroscience has held to the idea that the brain’s individual areas are for specific purposes, which is certainly true. However, the network of these brain locations and the functionality of that network is just as important. Understanding how the brain works as a whole is just as vital as knowing what each individual part does independently.

Ongoing research on DTD will undoubtedly shed light on this neurological condition as well as on how our brains work in general. For the number of people affected by DTD it could also offer some hope for a cure.

References and Related Studies

Bianchini, F., Palermo, L., Piccardi, L., Incoccia, C., Nemmi, F., Sabatini, U., & Guariglia, C. (2014). Where am I? A new case of developmental topographical disorientation. Journal of neuropsychology8(1), 107-124. Retrieved from http://www.researchgate.net/profile/Laura_Piccardi/publication/234821791_Where_Am_I_A_new_case_of_developmental_topographical_disorientation/links/09e415108e9c555790000000.pdf

Foley, K. (2015, May 18).  When the Brain Can’t Make Its Own Maps.  Retrieved from http://www.theatlantic.com/health/archive/2015/05/when-the-brain-cant-make-its-own-maps/392273/

Getting Lost: Understanding Human Navigation.  Site: https://www.gettinglost.ca

Iaria, G., Bogod, N., Fox, C. J., & Barton, J. J. (2009). Developmental topographical disorientation: Case one. Neuropsychologia47(1), 30-40. Retrieved from http://thinkingskillsclub.com/wp-content/uploads/2014/04/developmental_topographical_disorientation_-_iaria.pdf

Palermo, L., Piccardi, L., Bianchini, F., Nemmi, F., Giorgio, V., Incoccia, C., … & Guariglia, C. (2014). Looking for the compass in a case of developmental topographical disorientation: A behavioral and neuroimaging study. Journal of clinical and experimental neuropsychology36(5), 464-481. http://www.tandfonline.com/doi/abs/10.1080/13803395.2014.904843#.VaknaHh7uF4