Look or Listen? Which Channel do People Rely on More?

In our day to day lives, we are sometimes presented with information from two different channels of information, and sometimes this information can be incongruent. For example, if someone were to give directions and point left but say right instead. In situations such as these, which information channel do people rely on? To answer this question, we conducted two experiments. In Experiment 1, participants followed instructions from verbal and visual channels, that were sometimes incongruent, to move objects on their screens. In the first (training) block, probabilistic feedback either biased participants towards the verbal or the visual channel. The second (test) block contained no feedback. We found statistical learning of the bias in both verbal and visual conditions in the training block, although there was a stronger bias towards the verbal channel and much variability among participants. To investigate the origin of this variability, Experiment 2 removed feedback. Instead, participants completed two additional tasks: the Corsi Block and Digit Span tasks, which measure visual and verbal working memory, respectively. The results showed that people with higher visuospatial working memory showed less bias towards relying on the verbal channel. Collectively, these data suggest a bias towards prioritizing verbal information unless people have strong visuospatial working memory or the environment signals that the verbal channel is less reliable.