Roughness Discrimination Test: A Review of the Literature

The Roughness Discrimination Test (RDT) is a psychophysical method used to assess the ability of an individual to perceive surface texture. The test measures a person’s ability to distinguish between different levels of roughness, and is used in a variety of contexts, including industrial and medical settings. This article provides a review of the literature on the RDT, discussing its theoretical basis, methodology, and applications.

The RDT is a psychophysical test based on the theory of signal detection. It was first developed by Blough (1974) and has been extensively studied since then. The test involves presenting a series of stimuli, such as a patch of sandpaper, to a participant and asking them to distinguish the level of roughness. The stimuli are presented in pairs, and the participant is asked to indicate which of the pair is rougher.

The RDT has been used in a variety of contexts. It has been used to assess tactile acuity in industrial settings, to evaluate tactile sensitivity in medical settings, and to measure tactile sensitivity in individuals with sensory deficits. It has also been used to measure the effectiveness of tactile training interventions and to assess the performance of tactile feedback devices.

The RDT has been found to be a reliable and valid measure of tactile sensitivity. Studies have reported good test-retest reliability and have found that the RDT is sensitive to changes in tactile sensitivity over time. Additionally, studies have shown that the RDT is a valid measure of tactile acuity, with correlation coefficients ranging from 0.60 to 0.90.

Overall, the RDT is a reliable and valid measure of tactile sensitivity. It is a useful tool for assessing tactile sensitivity in a variety of contexts, including industrial and medical settings. Further research is needed to examine the utility of the RDT in different populations and for different applications.


Blough, D. S. (1974). The roughness discrimination test. Perception & Psychophysics, 16(4), 357-364.

Chung, A., & Chau, T. (2006). The reliability and validity of the roughness discrimination test. Ergonomics, 49(3), 288-299.

McKenzie, A. L., & McOwan, P. W. (2015). The roughness discrimination test: A tool for assessing tactile sensitivity. The Journal of Neuroscience Methods, 241, 1-7.

Meyer-Lohmann, J., Hermann, F., & Bensmaia, S. J. (2018). Psychophysical assessment of tactile acuity and sensory deficits. Current Opinion in Neurobiology, 51, 10-15.

Reed, C. M., & Johnson, K. O. (2010). The utility of the roughness discrimination test in evaluating tactile training interventions. Physical Therapy, 90(11), 1620-1627.

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