Processing of attended and ignored words in the parafovea: inhibitory aspects of semantic processing

Résumé 0

The idea that attentional selection is carried out by means of facilitatory aswell as inhibitory mechanisms has gained support in the past few years. Withthe aim of studying the influence of these mechanisms in languageprocessing, we have used the semantic priming experimental procedure witha parafoveal presentation of two words in the prime display. One of theprime words was to be attended to (attended prime) and the other was to beignored (distractor). Participants responded with a lexical decision task onthe subsequent probe word. In the first experiment we manipulated the SOAbetween prime and probe at four levels: 250, 450, 650 and 850 ms. At all theSOA levels, we obtained facilitatory effects for probes related to theattended primes. However, inhibitory effects for probes related to ignoredprimes were only obtained with SOAs of 450, 650 and 850 ms. Thefacilitatory and inhibitory effects with an SOA of 850 ms were replicatedwith different experimental conditions in Experiments 2 and 3. The absenceof negative priming in the 250 ms SOA supports the idea that the inhibitorymechanism is linked to a controlled and strategic processing. The attentionalfacilitation, however, can be produced either in an automatic or a controlledway. Moreover, we observed a consistent pattern of lateralization of theeffects of facilitation and inhibition, given that the mentioned effects wereonly produced for primes presented in the right visual field. This pattern oflateralization is discussed in relation to the functional differences betweenthe right and left hemispheres regarding semantic processing.