Per studies by Keetels and Vrooman (2012) and Moreno and Mayer (2000), sensory information is processed at different rates. Neurons are able to process sensory information at different rates relative to the modes involved. While the Colavita visual dominance effect recognizes this, it emphasizes any combinations that include visual modes. The principle of temporal synchronicity considers combinations in any modal form, including those that use the same mode such as two forms of visual information—print-linguistic text and video, for example. Such an issue is important to a theory of cognition because the rate at which information can be processed affects the rate at which cognition may occur. Multimodal rhetoric involves ascertaining optimal combinations of modes to facilitate cognition.
Moreno and Mayer had four different modal combinations relative to timing of the information. In their studies, they found that when information from visual and auditory modes was processed at the same time, learners were able to acquire information better than when the same kind of information was facilitated via two kinds of visual information at the same time (animation and text). However, they also found that learners tended to transfer knowledge better when they learned via a sequence of different modal information—watching an animation and then hearing a narration about what they viewed.
Such findings indicate that the types of modes involved and timing of information provided affect the efficiency of processing it. As mentioned above, when audio stimuli are presented several milliseconds before the visual stimulus is presented, participants perceive that the audio precedes the visual. Consequently, timing of exposure associated with certain modal combinations becomes part of the rhetorical effectiveness of those combinations. As considered with the Colavita visual dominance effect, the visual is the fastest sense engaged, but it takes the longest to process information. However, sound takes less time to process. When both visual and auditory senses are stimulated, both are attended to by the audience. Perhaps this influences the first attribute stated above— inter-modal redundancy and the desire for more senses to be engaged in cognition. That is, combining senses to help facilitate cognition enables the system to process information faster. As indicated earlier, though, the timing of sensory engagement or modal presentation can affect the degree to which particular neurons are engaged and, consequently, how information is processed (Spence, Parise, and Chen, 2012).
Also, head injuries and brain disorders that affect the various cortices impact how the brain can process information. Consequently, scholarship in neurobiology/physiology is considering more precisely how such injuries and disorders affect what may be considered effective rhetorical combinations within learning and perception generally. Examples of such research include: autism; brain injuries; lost or low vision; deafness; and neurological disorder or injury that causes numbing of touch sensory experience. As mentioned in the previous chapter, neuro-physiological scholarship finds that combinations of visual and touch senses contribute to understanding how to interact with physical objects; if one can hold an object but not feel it, how would that impact one’s perception of it?