Effects of spatially oriented attention on the facilitation of the H reflex by a cutaneous stimulus.

The effects of spatially oriented attention on the facilitation of the H reflex induced by a mild electrical stimulation of the sural nerve was investigated in 11 human subjects. The H reflex facilitation produced by the cutaneous stimulus was smaller when attention was focused on this stimulus than when it was directed to the same cutaneous field on the opposite leg. This demonstrates that selective attention involves specific descending controls on the spinal circuits mediating the segmental effects of cutaneous afferents.