Figure 1
From: Bilateral vestibulopathy causes selective deficits in recombining novel routes in real space
(adapted from reference 19,21).
Navigation paradigm in real space. (a) All subjects performed a navigation paradigm in a complex and unfamiliar spatial environment to test their spatial orientation performance. The area, in which five target items (pictures of ball/mushroom/flower/train/house) had been placed, was shown to the subjects first on an investigator-guided walk (exploration, upper panel, left side). Afterwards subjects had to find the items in a defined pseudo-randomised order over the next 10 min beginning from the starting point (red square). The first five routes in the navigation paradigm were identical to the previous exploration routes and therefore had to be simply retraced (referred to as retraced familiar routes in the manuscript) (upper panel, middle). Then, the order of target items was changed in a way that required recombining novel routes (referred to as recombined novel routes in the manuscript) (upper panel, right side). Potential shortcut routes were registered (lower panel, right side). The sequence of items during navigation is depicted in a table (lower panel, left side) and appears as numbers beside the target items in the figures. (b) Subjects wore a gaze-monitoring head camera throughout the experiment to allow post-hoc analysis of their visual exploration. (c) [18F]-FDG was injected at the start of the 10-min navigation phase. After the end of navigation testing subjects rested in a supine position for 20 min and image acquisition started 30 min after tracer administration. By this method navigation-induced brain activations could be depicted because the cerebral glucose utilisation is weighted to the 10 min following [18F]-FDG injection and is integrative due to intracellular trapping of the tracer
