L'attention sélective : l'effet du critère de sélection

Abstract

Summary : Selective attention : effect of selection criterion. We investigated how subjects ability to ignore the global and local aspects of a nonattended objet was affected by the criterion used to select the attended object. Two large letters (global aspect) constructed front small letters (local aspect) were presented ; one large letter was surrounded by a square while the other was enclosed in a circle. Subjects were required to attend either to the global or the local aspect of one of the compound stimuli (attended object) and to ignore a distractor located at the global or local aspect of the nonattended object. Three selection criteria were used to define the attended object : a) shape, b) brightness, or c) spatial location. The results show that when shape and brightness selection were required, the ease of ignoring the aspects of the nonattended object was dependent upon the direction of attention. When attention was global-directed, subjects could ignore the local, but not the global aspect of the nonattended object. On the other hand, under local-directed attention, subjects were unable to ignore the local aspect, while they could easily ignore the global aspect of the nonattended object. However, selectivity of attention was greatly improved when the relevant object was located on the basis of its spatial location and, regardless of the direction of attention, subjects were able to ignore both aspects of the nonattended object. The results are discussed in terms of the attentional spotlight metaphor. Key words : selective attention, selection criterion, global/local aspects.