Abstract: An experiment of semantic Negative Priming (NP) using a Lexical Decision Task (LDT) is reported. This effect (Tipper, 1985) is considered by some theories as a result of an attentional inhibitory mechanism, and it has been shown with different tasks and stimuli. In this experiment time course and lateralization of NP are explored. Four levels of SOA are used (250, 450, 650 and 850 msec). In prime display two words were presented, one on the left and another on the right of fixation point. One word was cued by a mark and subjects had to attend to it and ignore the other word. In probe display only a letter string (word or nonword) was presented, which was related to the attended prime, to the ignored prime or unrelated to both. Subjects had to respond with LDT. In long SOAs, Negative Priming from ignored primes, and Positive Priming from attended primes were obtained. Nevertheless, these effects were present only from words displayed at the Right Visual Field (RVF). With short SOA (250 msec) Positive Priming was obtained from both attended and ignored primes. This pattern of results is in concordance with a view of NP as a product of attentional controlled inhibition, which need time to develop.

IV Congreso Europeo de Psicología.
Atenas, 1995.