Contact Force and Duration Effects on Static and Dynamic Tactile Texture Discrimination

Tactile roughness magnitude estimates increase with contact force. However, it is not known whether discrimination thresholds are affected by contact force and other parameters, such as duration and tangential movement. The effects of these factors on roughness discrimination thresholds were determined using an adaptive staircase procedure for coarse and fine texture discrimination during active touch. The presence of tangential movement (dynamic touch) significantly reduced thresholds in coarse and fine texture discrimination compared to static touch, with effects more marked with fine textures. Contact force did not affect discrimination except in static touch of coarse texture when the threshold was significantly higher with low force. Within the perspective that texture discrimination involves distinct vibratory and spatial mechanisms, the results suggest that spatial-dependent texture discrimination deteriorates when contact force is reduced whereas vibration-dependent texture discrimination is unaffected by contact force. Texture discrimination was independent of contact duration in the range 1.36s to 3.46s, suggesting that tactile integration processes are completed relatively quickly.

[1]  John Cohen.  The World of Touch , 1952, Nature.

[2]  M. M. Taylor,et al.  Fingertip force, surface geometry, and the perception of roughness by active touch , 1972 .

[3]  A. Goodwin,et al.  Tactile discrimination of gratings , 2004, Experimental Brain Research.

[4]  M. R. DeLong,et al.  Tactile spatial acuity and roughness discrimination: Impairments due to aging and Parkinson's disease , 1997, Neurology.

[5]  M. Hollins,et al.  Evidence for the duplex theory of tactile texture perception , 2000, Perception & psychophysics.

[6]  Kenneth O. Johnson,et al.  The roles and functions of cutaneous mechanoreceptors , 2001, Current Opinion in Neurobiology.

[7]  J J Zwislocki,et al.  On a psychophysical transformed-rule up and down method converging on a 75% level of correct responses , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[8]  G. Lamb,et al.  Tactile discrimination of textured surfaces: peripheral neural coding in the monkey. , 1983, The Journal of physiology.

[9]  François Tremblay,et al.  Tactile perception and manual dexterity in computer users , 2002, Somatosensory & motor research.

[10]  Kenneth O. Johnson,et al.  Neural Coding Mechanisms in Tactile Pattern Recognition: The Relative Contributions of Slowly and Rapidly Adapting Mechanoreceptors to Perceived Roughness , 1997, The Journal of Neuroscience.

[11]  C. E. Chapman,et al.  Relative effects of the spatial and temporal characteristics of scanned surfaces on human perception of tactile roughness using passive touch , 2000, Experimental Brain Research.

[12]  Kenneth O. Johnson,et al.  Neural Coding Mechanisms Underlying Perceived Roughness of Finely Textured Surfaces , 2001, The Journal of Neuroscience.

[13]  Astrid M L Kappers,et al.  Frequency discrimination between and within line gratings by dynamic touch , 2002, Perception & psychophysics.