Sensuous processes in this research include the minor processes of affection and perception in Halliday's mental processes. They are the processes of sensing of animate things, including plants and animals, especially human beings.
Halliday (1994: 106) groups together clauses of feeling, thinking and perceiving under the general heading of mental processes, because all the three processes express the inner experience", or "what we experience as going on inside ourselves, in the world of consciousness and imagination".
Though Halliday is right in claiming that all the three minor processes of perception, affection and cognition are used to express the inner experience, they are intuitively different. The processes of perception and affection share more similarities than they do with the process of cognition.
"In deciding what types of process to recognize, we resort to a combination of common sense and grammar: common sense to distinguish the different kinds of 'goings-on'that we can identify, and grammar to confirm that these intuitive differences are reflected in language and thus to justify the decision to set up a separate category. We need to set up categories that are detailed enough to make us feel that we have captured something important about meaning, but broad enough to be manageable as the basis for general claims about the grammar of English [and other languages]." (Thompson, 1996: 79)
Intuitively, perception is the first step by which man gets to know the world via sensory organs, which are conveniently classified into five types: visual, auditory, olfactory, gustatory and tactile. Visual perception is the most important one, with the tactile, the auditory, the olfactory and the gustatory following in succession. "The quality of our perceptual experience depends ... on the stimuli that impinge on our sense organs and the signals directly induced by these stimuli."
Similarly, affection also depends on the outer stimuli that attract our sensory organs. Thompson even uses the word reaction" (Thompson, 1996: 85) to define it. All affections seem to be the result of outer input. Moreover, most emotions bring about physiological effects on the person who has the emotions. These physiological and sometimes physical effects are most of the time visible and sensible to the sense organs of others. Therefore, perception and affection are closely connected.