Il fenomeno della sordità da disattenzione nel paradigma di sguardo e ascolto selettivo

The influence of attention on perception is a much-discussed issue in the literature. Largely manifested in the Inattentional Blindness phenomenon (IB) (Mack & Rock, 1998; Most et al., 2005; Simons & Chabris, 1999), it has been extensively studied with respect of visual perception, but neglected in other sensory modalities like hearing. We investigated if IB could have an equivalent within the auditory modality: Inattentional Deafness (ID). Besides, we wonder how double-modality presentation of attended and unattended stimuli affects the presence and the extent of IB and ID. For these reasons we ran three different experiments, using the selective looking paradigm (Neisser, 1979); in every case the primary task was to count the bounces made by two teams passing two balls of different materials (making two different sounds) with wooden rackets. In experiments 1 and 2 the unattended stimulus was a black-dressed girl making a loud noise that crossed the visual field. In the last experiment the unattended stimulus was just auditory, thus the loud sound made by the girl, now invisible. Our data show that ID is a possible, strong and reliable phenomenon, and it can be increased in particular conditions, such as coupling the auditory modality of the primary task with the visual one (exp 1, 2 and 3) or pressing the space-bar in correspondence to the bounces (exp 2 and 3). We conclude that our results favor the existence of a non specific attentional system, shared between, and not within, modalities.