Human perception of self-motion and orientation during galvanic vestibular stimulation and physical motion
Fig 5
Mean model predictions (dashed lines) and σ bounds (grey shaded regions) generated by simulating the DC paradigm in Niehof et al. [22] are compared to their empirical data, unbiased by an average reporting bias of -0.43deg and time delay of 0.6s.
Corresponding model inputs (current without physical motion) are shown above the perceptions and model predictions. The model mean predictions largely lay within the SEM bounds of the 16-participant mean perceptions during an upright (i.e., no physical roll tilt) DC GVS stimulation paradigm. While DC GVS creates near-instantaneous changes in afferent firing rates (Fig 2), resultant perceptions of tilt for the onset of DC GVS stimulation contain delayed transient dynamics which eventually approach a steady state. Following the termination of DC GVS stimulation, perceptions of tilt demonstrate exponential decay with two dominant time constants. Our model predictions capture the time course of these temporal dynamics.