The Effects of Vocal Blocking on Sequencing Visual and Tactile Stimuli

The inclusion of private events in the philosophy of our science is integral to avoid dualism and remain objective rather than making assumptions about an unseen mind. However, the inclusion of behaviors and stimuli which cannot be observed in an analysis poses obvious issues. One established method of studying covert behavior is to examine tasks that are presumed to require verbal mediation, and observing how a participant's performance is affected when they are required to speak out loud during the task (often called "blocking"), again presuming this will make it difficult or impossible to simultaneously talk to yourself covertly. This study investigated the effects of vocal blocking on a sequencing task, or lining things up in a specified order. In one experiment, the items sequenced were abstract line drawings, and a second experiment used differently textured fabric stimuli (or "tactile cards"). In the second experiment, participants learned to tact and then sequence the tactile stimuli while they were blindfolded. The effect of vocal blocking on putative covert rehearsal was dissimilar across the two modalities of the experiments. This preliminary study provides insight into the nature of covert behavior as it relates to different senses and opens questions about the generality of studies examining covert mediation.