Development of a "pure-tactile" assessment of edge discrimination in the hands and oral cavity

Oral cavity edge perception acuity relative to the fingertip has previously been evaluated by the utilization of cognitively-loaded, stereognostic methods. However, with the lack of connection of the tongue to the visual association cortex, there is concern the superior acuity of the fingertip may be attributable to the cognitive component of the task. Here, perception acuity is evaluated by assessing participants' (n=29) just-noticeable-difference threshold for edge sharpness tiles using the finger and tongue. As expected, the pure-tactile task found greater acuity in the tongue, suggesting the cognitive component of the previous task confounded results and should not be used.