Abstract
The majority of research on the Stroop Effect has been focused on studying the conflict of incongruent information within one sensory modality. Relatively little research has been done to investigate crossmodal conflict in a Stroop task. Most crossmodal Stroop studies have only looked at visual-auditory conflict in one direction, i.e., how auditory distractors interfere with identification of visual stimuli. How visual distractors (either colour words or patches) might interfere with colour naming of spoken words remains unclear. Here, we present two experiments that address this issue. In Experiment 1, subjects (n=16) performed two audio-visual Stroop tasks. In one task, they had to identify a colour patch that was accompanied by a spoken colour word (auditory distractor). In the other task they had to identify the spoken colour word whilst looking at a colour patch (visual distractor). Congruency of auditory and visual stimuli was varied. Distractor presentations varied from 500ms before to 500ms after target presentation to examine the relative time course of the crossmodal Stroop effects in these two tasks. Experiment 2 (n=16) was similar to Experiment 1 except the visual stimuli were written words of colours. Our main results show similar Stroop effects when subjects had to identify spoken words with both colour patch and written word distractors across the entire SOA range. Conversely, a Stroop effect for identifying visual stimuli only occurred when the spoken word distractor occurred at least 400ms before visual presentation. Our results are the first to show similar Stroop-like effects of written colour words and colour patches on spoken colour word identification indicating that the crossmodal Stroop effect between auditory and visual stimuli is not unidirectional in nature. The results also show visual distractors exert stronger crossmodal Stroop interference. These findings provide new insight into the problem of how stimulus compatibility affects crossmodal processing.
Meeting abstract presented at VSS 2014