Extraocular proprioceptive projections to the visual cortex.

Electrical stimulation of the intraorbital part of the motor branches of extraocular muscles, where proprioceptive fibers run, evokes responses in 25% of the units of the striate cortex of the cat. The latency ranges between 25 and 40 msec. Mechanical stretch of extraocular muscles evokes multiunit responses in the striate cortex. The response is abolished by injection of xylocaine into the stretched muscle. The suppression of the response is reversible.