Although there are no agreed upon neuro-imaging criteria to diagnose ASP, there have been a number of studies that raise the potential for this possibility. In 2008, McAlonan et al. differentiated subjects with ASP and HFA on the basis of magnetic resonance imaging (MRI) differences in grey matter volumes [20], and in 2009 on the basis of differences in white matter volumes [21]. In 2011, Yu et al. differentiated ASP and ‘autism’ on the basis of grey matter volume: ‘Whereas grey matter differences in people with Asperger’s Syndrome compared with controls are sparser than those reported in studies of people with autism, the distribution and direction of differences in each category are distinctive’ [22]. However, the regions delineated by Yu et al. do not coincide completely with the regions defined by McAlonan et al. [20].
