Modified:
sense gate
This page is from my personal notes, and has not been specifically reviewed for public consumption. It might be incomplete, wrong, outdated, or stupid. Caveat lector.Traditional Buddhism describes six "sense bases" or gates: the eye, ear, nose, tongue, body, and mind. Western science usually omits the mind from this list, perhaps because we like to imagine that we have free will, but of course mental content is ultimately a perception just like everything else, and must be included if we are listing the full contents of awareness.
A slightly different take is Shinzen Young's system, where there are only the five senses (and only three, see/hear/feel, are really emphasized), but in addition to the usual outward versions each sense has an inward psychogenic counterpart. 'See out' is normal vision, while 'see in' is mental imagery, 'hear in' is mental talk, and 'feel in' is emotional body sensation. I think 'feel in' would also include the kinesthetic sense, our internal model of body pose in 3D space.
It actually doesn't seem to me that the five (or six) sense gates are really cleanly separated. Hearing is just the very precise sense of pressure on our eardrum - is that really fundamentally different from touch? And then, is inward hearing (mental talk) really so different from inward feeling (emotional body sensation)? At some level of practice, one sees clearly that all sense phenomena have one taste; they are all mental representations.