Subject-Specific Distortions in Haptic Perception of Force Direction

In a previous study, we found that the accuracy of human haptic perception of force direction is not very high. We also found an effect of physical force direction on the error subjects made, resulting in ‘error patterns’. In the current study, we assessed the between- and within-subject variation of these patterns. The within-subject variation was assessed by measuring the error patterns repeatedly over time for the same set of subjects. Many of these patterns were correlated, which indicates that they are fairly stable over time and thus subject-specific. The between-subject analysis, conversely, yielded hardly any significant correlations. We also measured general subject parameters that might explain this between-subject variation, but these parameters did not correlate with the error patterns. Concluding, we found that the error patterns of haptic perception of force direction are subject-specific and probably governed by an internal subject parameter that we did not yet discover.