A bedside application-based assessment of spatial orientation and memory: approaches and lessons learned

Abstract

Spatial orientation and memory deficits are an often overlooked and potentially powerful early marker for pathological cognitive decline. Pen-and-paper tests for spatial abilities often do not coincide with actual navigational performance due to differences in spatial perspective and scale. Mobile devices are becoming increasingly useful in a clinical setting, for patient monitoring, clinical decision-making, and information management. The same devices have positional information that may be useful for a scale appropriate point-of-care test for spatial ability. We created a test for spatial orientation and memory based on pointing within a single room using the sensors in mobile phone. The test consisted of a baseline pointing condition to which all other conditions were compared, a spatial memory condition with eyes-closed, and two body rotation conditions (real or mental) where spatial updating were assessed. We examined the effectiveness of the sensors from a mobile phone for measuring pointing errors in these conditions in a sample of healthy young individuals. We found that the sensors reliably produced appropriate azimuth and elevation pointing angles for all of the 15 targets presented across multiple participants and days. Within-subject variability was below 6° elevation and 10° azimuth for the control condition. The pointing error and variability increased with task difficulty and correlated with self-report tests of spatial ability. The lessons learned from the first tests are discussed as well as the outlook of this application as a scientific and clinical bedside device. Finally, the next version of the application is introduced as an open source application for further development.

Comparison of spatial orientation skill between real and virtual environment

“…The authors stated the ability to find one's way that involved basic perceptual and memory-related processes are seen as a complex construct due to the multisensory process in which information needs to be adjusted over space and time (Wolbers and Hegarty 2010). The correlation between the spatial orientation and memory is shown in a study in which deficits of them are known as an early marker for pathological cognitive declines (Flanagin et al 2019). Therefore, different tests were used to analyze spatial memory by letting the participants conduct a test that required them to memorize the order of objects on a map and to reconstruct it from memory (Lehnung et al 1998).…”

“…The authors emphasized the meaning of both reference systems but also referred to studies that crystallized the egocentric reference system as the dominant role to specify objects' locations (Battaglia-Mayer et al 2003;Klatzky 1998). For measuring environmental spatial abilities, pointing is a commonly used method that can be varied to examine different aspects of spatial ability (Flanagin et al 2019;Kimura et al 2017). Kimura et al (2017) found out that participants could reorient by using either the geometry of the room or the implemented features (objects), whereas feature-based cues seem to have more impact on spatial ability skills in virtual environments.…”

Testing Navigation in Real Space: Contributions to Understanding the Physiology and Pathology of Human Navigation Control

“…Functional MRI (fMRI) based studies are mostly possible in 2D paradigms and hard to achieve in immersive VR set-ups. Examples of real space spatial orientation and navigation testing by (D) pointing experiments to a known position in vista space (Flanagin et al, 2019) and (E) navigation in large-scale environments. Navigation strategy and visual exploration patterns are recorded by a head-mounted eye-tracking system and are analyzed post hoc in navigograms.…”

Different strategies in pointing tasks and their impact on clinical bedside tests of spatial orientation

“…These basic activities qualify for a quick clinical bedside test of a patient’s ability to perform spatial navigation and orientation. A first prototype of our handheld pointing device using the inbuilt sensors of an Apple iPhone® showed promising results [ 6 ]. While this approach did show the principal feasibility of harnessing the sensor output from a modern smartphone for neuroscientific navigation testing, it relied on GPS and compass information, therefore, suffering from limited applicability indoors (as positioning via GPS does require an uninterrupted line-of-sight towards the satellites orbiting earth) and proneness to errors in the presence of magnetic fields.…”

“…In the following, we will first discuss structural and functional aspects of spatial orientation, the specific meaning of pointing as a fundamental element of interaction with the environment and its fallibility when using pointing as a quantitative measure for spatial orientation. Then, we will analyze the shortcomings of the methods and the pointing device used in our initial description for a bedside application-based assessment [ 6 ]. Finally, we will propose a further developed pointing device with a modified standardized test paradigm and report the preliminary data of a pilot experiment in healthy participants.…”