London: British researchers have identified subtle differences in the brains of adult males with autism spectrum disorder (ASD). The subtle brain differences were found in men who at a very young age had severe problems with communication and social interaction, the study showed.
"The differences appear to remain even if they have somehow learned to cope with these difficulties in adult life," said Marco Catani from the King's College London.
The study revealed that men with ASD had differences in brain connections in the frontal lobe -- a part of the brain that is crucial for developing language and social interactive skills, the researchers said.
Specifically, these men had altered development of white matter connections in the left side of the brain.
White matter consists of large bundles of nerve cells that connect different regions of the brain and enable communication between them.
The differences, which connects areas of the brain involved in understanding words and regions related to speech production, were particularly severe in those who had a significant history of 'delayed echolalia' -- parrot-like repetition of words or sentences, the researchers explained.
ASD was also associated with underdevelopment of white matter, which plays a significant role in face recognition and emotional processing, the findings revealed.
This also correlated with observations of inappropriate use of facial expressions in childhood.
ASD affects around one in 100 people in Britain and involves a spectrum of conditions that manifest themselves differently in different people.
People with ASD can have varying levels of impairment across three common areas, which might include: deficits in social interactions and reciprocal understanding, repetitive behaviour and narrow interests, and impairment in language and communication, the researchers said.
The study, published in the journal Brain, used a novel brain imaging method to identify altered brain connections in people with ASD.
The researchers used Diffusion Tensor Imaging (DTI), a Magnetic Resonance Imaging (MRI) technique, to compare networks of white matter in 61 adults with ASD and 61 controls.