Where did you get your information?  I googled and searched because I always thought that the knock sensor retarded the timing, and everything I can find says the same thing.  During acceleration, older cars used vacuum and mechanical weights to advance the timing to improve performance.  Advanced timing provides the best power during hard acceleration but if the compression ratio is too high for the octane of fuel, detonation can occur.  This is very harmful so advancing was always limited and octane levels specified to stay in a safe range.  Computers are able to advance timing till knocking is detected then retard the timing a little.  Higher octane fuels allowed the timing to be advanced further but regular engines don't benefit because the timing will not advance beyond a certain point.  Premium fuel has lower volatility so regular engines cannot benefit from using it, and in fact, may perform worse with poorer fuel economy.