The overlap figure shrank in February with new research by Paul Mellars of Cambridge University based on improved carbon-14 dating to show that modern humans started encroaching from Israel upon Neanderthal territory in the Balkans 3,000 years sooner than previously thought.
This rate suggests Neanderthals succumbed sooner to big climate shifts or competition from modern humans for resources and that they might have overlapped for only 1,000 years at sites in western France.
As John Hawks notes, there is now no evidence that Neandertals and modern humans overlapped at all in Europe. I am not sure how many people are going to go for the idea that Neandertals were responsible for the Aurignacian, however.