Visual thinking uses images as tools to allow the creative and emotional part of the brain to process information in an intuitive manner. Applying sensory, imaginative experience, visualization and perceptual thinking — in contrast to logical reason, verbal communication and critical thinking — is one of the most effective ways to develop creative ideas and turn complex problems in to clear solutions.
First codified by Harvard's Rudolph Arnheim in his seminal 1969 book, visual thinking can be used to observe, record, organize, evaluate and manifest ideas.
Further reading here.
Video by Sean Kelly on VIMEO.