Tactile spatial acuity differs between fingers: a study comparing two testing paradigms.
Tactile spatial acuity (TSA) is a reliable and reproducible measure of somatosensory system function that has been used to study abroad range of subject populations. Although TSA is most often assessed at the fingertip, published studies employing identical stimuli disagree on whether TSA differs between the fingers of neurologically normal subjects. Using a validated grating orientation discrimination task, we determined TSA bilaterally at the index and ring fingers of 16 healthy young adults. Motivated by earlier work, we utilized two stimulus presentation paradigms, the method of constant stimuli (MCS) and a staircase (SC) method. We found that TSA was significantly higher (the discrimination threshold was lower) at the index than at the ring finger, which was consistent with a prior study. Although mean thresholds at both fingers were higher when measured with the SC than with the MCS paradigm, this difference did not reach statistical significance (p = .14). These findings should facilitate both design and interpretation of future studies investigating TSA.
Grant
Arthur C
AC
New York University School of Medicine, NY 10016, USA. arthur.grant@med.nyu.edu
Fernandez
Raquel
R
Shilian
Parastou
P
Yanni
Elizabeth
E
Hill
Mary Ann
MA
D000293:Adolescent; D000328:Adult; D005260:Female; D005385:Fingers / Q000502:physiology*; D006801:Humans; D008297:Male; D013028:Space Perception; D014110:Touch / Q000502:physiology*; D014792:Visual Acuity; D014796:Visual Perception