Surface exploration using instruments: the perception of friction.

The purpose of this study was to investigate the ability to discriminate friction during surface exploration using a finger and surgical instrument under normal vision and when vision was absent. Participants explored surfaces with either with the finger or with an instrument and rated the slipperiness. Results showed that the explorations with the instrument were estimated to be more slippery and less sensitive than those for the finger. There were no effects for visual condition. This study showed that novices who use instruments to make estimations of tissue slipperiness require practice and training in order to adequately perceive friction. Novices' reduced ability to perceive friction with instruments should be integrated into simulator design.