Abstract

We report the results of a human eyeblink conditioning procedure aimed at characterizing different types of responses. To do this, eight participants received an auditory conditioned stimulus paired with an unconditioned stimulus -air puff in the eye- and a vibro-tactile stimulus non reinforced. We demonstrated the existence of four responses. In the first 100 milliseconds (ms) since the initiation of conditioned a small amplitude response, called alpha, appears, which is followed by intermediate amplitude responses, called voluntary (200-300 ms) and conditioned (300-400 ms). Finally, the largest-amplitude responses occur about 200 ms after unconditioned stimulus onset. Both voluntary and conditioned responses are more frequent in the presence of stimulus A that B. We discuss the relevance of identifying and distinguishing these types of responses in any classical conditioning routine.