In a further study published in "Neurocase" in 2008, Baron-Cohen, Bor and Billington investigated whether Tammet's synaesthesia and Asperger syndrome explained his savant memory abilities. They concluded that his abilities might be explained by hyperactivity in one brain region (the left prefrontal cortex), which results from his Asperger syndrome and synaesthesia. On the Navon task, relative to non-autistic controls, Tammet was found to be faster at finding a target at the local level and to be less distracted by interference from the global level. In an fMRI scan, "Tammet did not activate extra-striate regions of the brain normally associated with synaesthesia, suggesting that he has an unusual and more abstract and conceptual form of synaesthesia". Published in "Cerebral Cortex" (2011), an fMRI study led by Jean-Michel Hupé at the University of Toulouse (France) observed no activation of colour areas in ten synaesthetes. Hupé suggests that synaesthetic colour experience lies not in the brain's colour system, but instead results from "a complex construction of meaning in the brain, involving not only perception, but language, memory and emotion".