| Popis: |
As mentioned in the project preregistration, we would like to explore whether spatial processing during a seemingly automatic multisensory integration phenomenon like the sound-induced flash illusion, can be modulated by attentional load. In Experiment 1, it will be used a dual-task that combines a primary audiovisual integration task with stimuli eliciting the sound-induced-flash illusion presented on the left or on the right side of the screen and a concurrent secondary working memory task to manipulate levels of attentional load in younger adults. Specifically, in the encoding phase of the working memory task, participants will have to memorize short or long sequences (low/high load) of consonants or spatial positions (verbal/spatial load). Thereafter, in the audiovisual integration task, they will be presented simultaneously with one or two lateralized flashes and binaural sounds and will have to report the number of perceived flashes. Usually, accuracy in reporting the number of perceived flashes is higher when the number of flashes and sounds is congruent (1F1S and 2F2S trials), while it drops when it is incongruent, as sounds influence flashes perception in an illusory way (1F2S and 2F1S trials); specifically, 1F2S trials can lead to split the visual percept and to report two flashes (i.e., fission illusion), while 2F1S trials can induce to merge the visual percepts and to report one flash (i.e., fusion illusion) (Andersen et al., 2004; Shams et al., 2000, 2002). Finally, in the test phase of the working memory task, participants will have to report the sequences of previously encoded stimuli. This procedure allows to vary load offline, indeed the working memory stimuli used to manipulate load will be presented before audiovisual integration stimuli. A peculiarity of the experiment is that participants recruitment and data collection will take place entirely via web. |
