Non-invasive imaging of neuronal population dynamics in human thalamus.

Waveforms for early thalamic and cortical population responses to unilateral median nerve stimulation at the wrist were determined non-invasively for six subjects from 122-channel magnetoencephalographic data. Biphasic responses in contralateral ventral thalamus were obtained in 9 hemispheres similar to depth-electrode results reported for patients. Thalamic responses occurred at 15.1-17.4 and at 19.2-24 ms. Responses in contralateral sensorimotor cortex began at 16.3-18.8 ms.