Halliday & Matthiessen (1999: 142):
The different types of sensing have somewhat different potentials for unfolding in time. With perception and cognition we have various categories of duration, inception, and the like: e.g. (perception) glimpse, sight, spot as well as see; (cognition) discover, realise, remember as well as know. But similar distinctions do not seem to obtain with desiderative and emotive processes.