Related Experiment Video
Updated: Aug 12, 2026

Design, Fabrication, and Administration of the Hand Active Sensation Test (HASTe)
Published on: September 8, 2015
Distal-proximal somatotopy in the human hand somatosensory cortex: a reappraisal
I Hashimoto1, Y Saito, Y Iguchi
1Department of Psychophysiology, Tokyo Institute of Psychiatry, 2-1-8 Kamikitazawa, Setagaya-ku, Tokyo 156-8585, Japan. ihashi@prit.go.jp
Abstract:
The distal-proximal representation of the finger and palm in the first somatosensory cortex was reexamined. Somatosensory evoked magnetic fields (SEFs) were measured with a 37-channel first-order axial gradiometer system. Sensory stimulus comprising a 20-ms vibration at a frequency of 200 Hz was delivered to five successive sites in 3-cm increments along the distal-proximal direction over the volar surface of the right index finger and palm. Using a single dipole model, the sources and the signal strengths of the main peak (M50) of the SEFs were estimated. All of the sources were located in the 3b area. There were no statistically significant differences between the locations of dipoles evoked by stimulation of different sites. The results support those of our previous study using a 122-channel whole-head planar gradiometer system that orderly distal-proximal representation of the hand, as described in monkeys, is blurred in the adult human somatosensory cortex.
Related Concept Videos
Somatosensation
Motor and Sensory Areas of the Cortex
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.
Sensory Perception: Organization of the Somatosensory System
The receptor level:
The receptor level is the first stage of sensation. It involves the detection of a stimulus by specialized sensory receptors. The stimulus must arrive within the receptor's receptive field. Next, the receptor converts the energy of the stimulus...
Overview of Somatic Sensory Pathways
The somatosensory system is divided into three main pathways: the dorsal (or posterior) column-medial lemniscus, spinothalamic (or anterolateral), and spinocerebellar pathways.
The dorsal...
Major Somatic Sensory Pathways
Somatosensory, Motor, and Association Cortex

