The Connection between Body Representation and Tactile Sensation Thresholds

In order to accurately interpret tactile information, the brain needs to have an accurate representation of the body to which to refer the sensations. Despite this, body representation has only recently been incorporated into the study of tactile perception. The effect of body representation on tactile thresholds was explored in two different ways. First, tendon vibration illusions were used to investigate whether distortions of body representation affect tactile sensations. Tactile acuity and sensitivity were increased when perceived size of the arm and waist were altered. Secondly, masking was used to investigate whether stimulation to one part of the body representation alters thresholds at other sites. Contralateral masking on the arms was found, along with spatial tuning of this effect. Masking through the body was also demonstrated by measuring the effect of a masking stimulus on the back on the tactile sensitivity of the corresponding point on the front.