Insight, then. Wisdom. The quest for knowledge, the derivation of theorems, science and technology and all those exclusively human pursuits that must surely rest on a conscious foundation. Maybe that's what sentience would be for — if scientific breakthroughs didn't spring fully-formed from the subconscious mind, manifest themselves in dreams, as full-blown insights after a deep night's sleep. It's the most basic rule of the stymied researcher: stop thinking about the problem. Do something else. It will come to you if you just stop being conscious of it.