Table 4.

Tactile spatial acuity at the right index finger pad as measured in previous studies

Acuity threshold (mm)	Test used	Reference
0.87	Gap detection (m)	Johnson and Phillips, 1981
	Grating orientation
0.84	discrimination (m)	Johnson and Phillips, 1981
	Grating orientation
0.98	discrimination (h)	Van Boven and Johnson, 1994
	Grating orientation
0.96	discrimination (h)	Sathian and Zangaladze, 1996
	Grating orientation
1.23	discrimination (h)	Vega-Bermudez and Johnson, 2001
	Grating orientation
1.06	discrimination (h)	Grant et al., 2006

m, Mechanized stimulator used; h, hand-held stimulus.