Figure 1.

Tactile responses of a neuron from the PZ. (A) The monkey sat in a chair with the arm extended through a hole and strapped in an arm holder. The Plexiglas plate surrounding the arm could be moved laterally, thereby touching the arm. The striped area on the medial surface of the arm indicates the tactile receptive field. This tactile receptive field extended up the arm and ended about halfway between the elbow and arm pit. (B) The firing rate (mean of 10 trials) during tactile stimulation caused by the experimenter pushing the arm such that the tactile receptive field came into contact with the adjacent Plexiglas chair part. (C) The firing rate (mean of 10 trials) during tactile stimulation caused by the experimenter moving the chair part such that it touched the tactile receptive field on the arm. (D) The firing rate (mean of 10 trials) during tactile stimulation with a cotton swab on the same part of the tactile receptive field that touched the chair part in B and C. (E) The firing rate (mean of 10 trials) during tactile stimulation with a disconnected piece of Plexiglas on the same part of the tactile receptive field that touched the chair part in B and C.