Lateralized brain dysfunction in autism: evidence from the Halstead-Reitan neuropsychological battery.

Richmond (1983) gave autistic kids the Halstead-Reitan battery. This is a set of hands-on tasks that show how each side of the brain is working.

Kids also took IQ tests. The team compared scores to two control groups: kids with mental retardation and kids with diffuse brain damage.

The autistic group had more left-side brain dysfunction than both control groups.

Each autistic child showed a clear pattern: left-side scores were worse than right-side scores. The other groups did not show this pattern.

McGee et al. (1983) used dichotic listening in the same year and found normal left-ear bias for language. That seems opposite, but the tasks differ. The battery tests many skills; dichotic listening tests only sound perception.

Mansell et al. (2002) later narrowed the problem. They showed left-hemisphere issues appear only on executive tasks in high-functioning autism. Asperger’s subjects looked typical.

Audras-Torrent et al. (2021) pooled decades of imaging and found weaker semantic-network activation in autism. Their meta-analysis quietly includes the 1983 result, turning one small study into part of a big picture.

Matson et al. (2013) muddied the water: rightward brain asymmetry, not left damage, linked to higher symptom severity. The story is no longer “left side broken,” but “lateralization itself is off.”

When you see a client struggle with left-side tasks like rapid naming or fine motor sequencing, remember this lateralized profile. It is not global delay; it is uneven wiring. Use that insight to pick assessments and to explain why one skill lags while another shines.