Although the response of human cutaneous mechanoreceptors to controlled stimuli is well studied, it is not clear how these peripheral signals may be reflected in neuronal activity of the human central nervous system. We now test the hypothesis that neurons in the human thalamic principal somatic sensory nucleus (ventral caudal, Vc) respond selectively to the optimal stimulus for one of the four mechanoreceptors. The optimal stimuli for particular mechanoreceptors were defined as follows: Pacinian corpusles (PC) - vibration at 128 Hz, rapidly adapting (RA) - vibration at 32 Hz or 64 Hz, slowly adapting type 1(SA1) - edge, and slowly adapting type 2 (SA2) - skin stretch. Thirty Vc neurons studied in 12 thalami (10 patients). Nineteen of these neurons had a significant response to at least one optimal stimulus and seventeen had a significantly greater response to one stimulus than to the other three, termed mechanoreceptor-like neurons. There were 7 PC-like, 7 RA-like, 3 SA1-like and 2 SA2-like neurons. One of each of the SA1- and SA2-like thalamic neurons responded to vibration with firing rates which were lower than those to edge or stretch, but not significantly lower. Except in the case of PC-like neurons the RF sizes were usually larger for mechanoreceptor-like neurons than for the corresponding mechanoreceptor. Von Frey thresholds were higher than those for the corresponding human RA and SA1 mechanoreceptors. These results suggest that there is convergence of pathways transmitting input from multiple mechanoreceptors of one type on single neurons in the dorsal column nuclei and thalamus. They are also consistent with the presence of thalamic elements of modality and somatotopic isorepresentation suggested by microstimulation studies in humans.