![]() ![]() We hypothesized that orientation across different domains relies on a shared “core” brain system, in close relation to the DMN, yet orientation in specific domains may involve additional specialized subsystems. Finally, we compared our results to the DMN as identified in each individual subject by analysis of resting-state fMRI. To capitalize on the spatial acuity of the high-resolution fMRI, we applied a strategy of analyzing each subject individually in native space and combined the results to compare activations for the three domains. To gain high anatomical specificity, we used high-resolution 7-Tesla functional MRI (fMRI). To this aim, we used a mental-orientation task, with individually tailored stimuli in the space (places), time (events), and person (people) domains. Here, we investigated the neurocognitive system underlying orientation in space, time, and person and its relation to the DMN. These findings suggest a common brain system for orientation across domains, possibly related to the DMN. Notably, these regions constitute a part of the default-mode network (DMN), a system involved in self-referential processes ( 24, 30– 35). ![]() ![]() However, other neuroimaging studies that investigated processing of places, events, and people separately have found activation in brain regions besides the IPL, including the precuneus and posterior cingulate cortices, medial prefrontal cortex (mPFC), and lateral frontal and temporal lobes ( 6, 13– 29). Accordingly, a recent neuroimaging study mapped cognitive distance estimations in the three domains to a single region in the inferior parietal lobe (IPL) ( 12). Behavioral studies indicate a common psychological metric for proximity estimations (“cognitive distance”) in space, time, and person ( 7) for example, manipulation of stimuli’s distance in one orientation domain affects the perceived distance in the other two domains ( 10, 11). Several lines of research support the idea that similar neurocognitive systems underlie orientation in these three domains. These findings suggest that mental orientation in space, time, and person is managed by a specific brain system with a highly ordered internal organization, closely related to the default-mode network. Finally, the default-mode network, identified in a separate resting-state scan, was active for all orientation domains and overlapped mostly with person-orientation regions. The medial prefrontal cortex showed a posterior activation for time and anterior for person. Core regions at the precuneus and inferior parietal lobe were activated for multiple orientation domains, suggesting also common processing for orientation across domains. Comparison of orientation domains revealed a consistent order of cortical activity inside the precuneus and inferior parietal lobes, with space orientation activating posterior regions, followed anteriorly by person and then time. Analysis at the individual-subject level revealed cortical activation related to orientation in space, time, and person in a precisely localized set of structures in the precuneus, inferior parietal, and medial frontal cortex. To unravel the neurocognitive basis of orientation, we used high-resolution 7T functional MRI as 16 subjects compared their subjective distance to different places, events, or people. Behavioral and neuroimaging studies have hinted at interrelations between processing of these three domains. Orientation is a fundamental mental function that processes the relations between the behaving self to space (places), time (events), and person (people). ![]()
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