Great point. I can imagine "AutoSense", a software app running on a synthmorph with no sense of smell that adds rose smell when you "sniff" a rose - it is actually a clipart rose smell from a standard public domain database. The pay version of AutoSense even does some nifty mechanics calculations to give you a fairly convincing (if false) sense of touch. This relates to the problem of making some morphs "comfortable" to live in. You can't breathe and you have no stomach as a Reaper, but phantom suffocation and hunger is pretty annoying. So there are patches in the cyberbrain to reduce such needs. But other morphs might solve it by adding fake stimuli ("Press this icon to start simulated breathing overlay"). Some 'clank cafés' on Mars may serve AR food to people in synthmorphs, where they get nice food tasting XP downloaded as they eat. I like the idea of sensory overlays. Add taste icons to the data, so you can notice the sourness of financial losses and the candy taste of profit in the accounting stream. Make weapon systems have characteristic "noises" depending on their state (including the ominous hum effect for weapon readiness and anime-gleams running along blades in proper sharpness condition). An air vehicle might tell you drag conditions by temperature and flight corridor number by a smell ("Ah, the jasmine of 15.848! We are almost there now."). Yesterday I listened to Amon Twyman giving a talk on "Augmented perception and Transhumanist Art", where he made the point that with augmentation we can of course mess around with the senses we got (change the colour appearance of the world, make custom synaesthesia etc.), but we can also take new information channels into our sensory space - translate radioactivity information into a nasty ozone smell, expand the spectral range to encompass infra-red (squeezing the spectrum, which makes familiar object look weirdly coloured) or make information fields feel like touch. This way we can experience a "penumbra" of our own reality that we normally do not experience directly. Amon argued that there is a realm of perceptions that are outside the penumbra that are impossible for human-type minds to perceive. We can not even map them onto working perceptions, we need to rebuild our brains. The above mappings still makes use of the modalities and qualia we got in our brain: infra-red gets mapped to the colour dark red, it is not experienced as a "new" colour or something as different from colours as sound is. To do that we need to either retrain the cortex quite a bit, or to add entirely new sensory cortices. I think EP tech is up to it, but it also makes your ego exhuman. A bit of psychosurgery to experience infra-red vision as a new qualia without having to change the rest of the spectrum might be odd enough, but plugging in extra cortex to perceive magnetic fields or multidimensional geometry will warp perception and thinking subtly. ("Have you ever felt 3-space to be *tight* and confining? Now I do. Besides, in this morph, I miss IR vision and hence it is as if one color is missing. Imagine being stuck in a narrow green-lit hallway all the time and you have my current reality.")