Interactions between inputs of different sensory modality occur along the sensory pathway, including the thalamus. However the temporal profile of such interaction has not been fully studied. In 8 patients who had been implanted an intrathalamic electrode for deep brain stimulation as symptomatic treatment of tremor, we investigated the interactions between mechanical taps and electrical nerve stimuli. Somatosensory evoked potentials (SEPs) were recorded from Erb's point, cervical spinal cord, nucleus ventrointermedialis of the thalamus and parietal cortex. A hand-held electronic reflex hammer was used to deliver a mechanical tap to the skin overlying the first dorsal interosseous muscle, and trigger an ipsilateral digital median nerve electrical stimulus time-locked to the mechanical tap with a variable delay of 0 to 50ms. There were significant time-dependent interactions between the two sensory volleys at subcortical level. Thalamic SEPs were decreased in amplitude at inter-stimulus intervals (ISIs) from 10 to 40ms with maximum effect at 20ms (-42.8±10.5%; p<0.001). A similar decrease was also seen in the number and frequency of the high-frequency components of thalamic SEPs (-25±4%). A smaller reduction (-18.1±5.8%; p<0.001) was present in upper cervical response at ISI=20ms. There were no changes in peripheral responses. Cortical SEPs were almost completely absent in some subjects at ISIs from 20 to 50ms. There were no changes in SEPs latencies. Our results indicate that significant time-dependent interactions between sensory volleys occur at subcortical level. These observations provide further insight on the physiological mechanisms underlying afferent gating between sensory volleys of different modality.