It's the transmission downshifting to a lower gear to aid in slowing down, same as you would do in a manual transmission, that is why the RPM's increase, but it is not really accelerating, although it may feel a bit like that. I just recently got a 2011 Camry and the transmission is horrible, and I have noticed the same issue and it is a bit unsettling, even though it's just a down shift, it doesn't do it as smoothly as it should. I am extrememly dissapointed in this car and in Toyota for making it. The engine is about the noisiest 4 cylinder I have ever driven in my life and putting a 6 speed transmission behind it makes it shift so erratically it drives me crazy. It will upshift so quiickly and then with the slightest TV pressure downshift again for a second, and then upshift right away again, it is madening. I've also noticed that when first started cold in the morning, even with a couple minutes of warm up time, when you put it in Reverse there is a huge lag time for the gear to engage and then it jumps into gear. My wife has gotten nervous about that a few times, and slammed on the brakes when it kicks in and jerks the car backwards. I replaced an '08 Pontiac Grand Prix with this '11 Camry for my wife, and I have to say the Grand Prix runs circles around this !Removed! of a car, in every aspect, including interior design and comfort. I've driven Toyota's since the 70's and have probably had close to 10 different models and almost 20 different Toyota vehicles and I'd fully say this Camry is the worst and that Toyota's quality has slipped greatly since I first started buying/driving them, especially compared to what domestic makers have been putting out. I'm counting the days until the Camry lease is up and may even cancel it early. I still have 2 other Toyota vehicles, but this Camry is a huge let down.