The explorative scanning movements of the hands have been compared to those of the eyes. The visual process is known to be composed of alternating phases of saccadic eye movements and fixation pauses.
Five different Experiments were used. The first two Experiments were classical recognition tasks of unknown haptic stimuli (A) and of common objects (B). In ExperimentC space-position information of angle legs had to be perceived and reproduced. ForExperiments D and E the PHANToM haptic device was used for the exploration of virtual(D) and real (E) sunken reliefs.
In each Experiment we observed explorative stops of different average durations. Significant correlations wereobserved between exploration time and the duration of the ES. Also, ES occurred morefrequently, but not exclusively, at defined stimulus features like corners, curves and theendpoints of lines. However, explorative stops do not occur every time a stimulus featureis explored.
We assume that ES are a general aspcect of human haptic exploration processes.
publication: Grunwald M., Muniyandi M., Kim H., Kim J., Krause F., Mueller, S., Srinivasan M.A. (2014). Human haptic perception is interrupted by explorative stops of milliseconds. Frontiers in Cognition, April 2014, Vol 5, Article 292, p.1-14