Twenty or more years ago, I read an article which claimed that people could be put into three categories based on internal mechanisms used while thinking. People in group A claimed to be aware of visual images related to their thoughts. For example: When such people thought about calender related concepts, they had an image of an irregular closed curve with various mental pictures indicating seasons or months of the year at various places along the curve. Many in this group were artists or sculptors, but many artists and sculptors were not included in this group. People in group B claimed to be aware of words in their natural language related to their thoughts. Many in this group were writers or journalists, but many writers and journalists were not included in this group. People in group C could not describe any internal process related to their thoughts. The author claimed that such people have some very abstract set of symbols used when thinking. Since the internal symbols are neither words nor visual images, the people in this group have no way of describing any process associated with their thoughts. I happen to belong to this group which tends to include mathematicians, scientists, programmers, and other technical types, although many in this group are not technical types. To which category do you belong? BTW: I am surprised that I dream in color with detailed visual images, since I cannot create a visual image of anything when I am awake.