Blink reflex induced by controlled, ballistic mechanical impacts

The blink reflex was induced by a defined mechanical impact covering the range from light touch to a hard, painful stroke, and by an electrical current. In both modes of stimulation, the R3--but not the R2--thresholds were correlated with subjective pain thresholds, suggesting a connection between R3 and nociceptor activation. However, R3 magnitude did not increase systematically with increasing levels of subjectively felt pain. The R3, induced by painful impacts, habituated quickly and was strongly affected by attention. The functional significance of the R3 component is discussed.