Is macrocephaly a neural marker of a local bias in autism?

•Local processing bias common to individuals with Autism Spectrum Condition.•Recent research suggests a link between a local processing bias and macrocephaly.•Results of this study of children with ASC further support this link.•Abnormal neural connectivity possibly the causal factor.•Characteristics represent an endophenotype in a subgroup of individuals with ASC.

Previous research has suggested that the local processing bias often reported in studies of Autism Spectrum Condition may only be typical of a subgroup of individuals with autism also presenting with macrocephaly. The current study examined a group of children with autism, with and without macrocephaly, on the Children's Embedded Figures Test (CEFT), a well-established measure of local processing bias. The results demonstrated that the children with autism and macrocephaly performed significantly better on the CEFT than children with autism without macrocephaly, indicative of a local bias. These results lend support to the proposal that both macrocephaly in autism and a local processing bias may arise from the same underlying neural processes and these characteristics represent an endophenotype in a subgroup of individuals with ASC worthy of further investigation.