Sometimes, a sensory image is associated with a thought in a meaningless way. For example, the color brown might be associated with a particular sound. In psychology, these are called epiphenomenal images. Some people experience this epiphenomenal imagery a lot. Most people do not. But everyone perhaps does it a little. For example, higher pitched tones are associated with height and probably seem smaller than lower pitched tones. Or, the "eee" sound is probably experiences as small.
In any case, complex thoughts can probably be associated with epiphenomenal images. Gendlin associates his felt senses with feelings in the body. The introspectionists Titchener made the same claim. He wrote: "I am sure that when I sit down to the typewriter to think out a lecture, and again to work off the daily batch of professional correspondence, and again to write an intimate and characteristic letter to a near friend -- I am sure that in these three cases I sit down differently. The different intention comes to consciousness, in part, as different feels of the whole body; I am somehow a different organism, and a consciously different organism. Description in the rough is not difficult; there are different visceral pressures, different distributions of tonicity in the muscles of back and legs, differences in the sensed play of facial expression, difference in the movements of arms and hands in the intervals between striking the keys, rather obvious difference in respiration, and marked differences of local or general involuntary movement."
However, it is possible to associate complex thoughts with abstract visual images. One teacher, when focusing, could associate his thought with a particular abstract black shape on a white background. When he told his class about this, they all started reported visual epiphenomenal imagery.
The epiphenomenal imagery is useful as a handle for the felt sense.