Tldr "The researchers found that certain regions of the cerebral cortex showed lower neuron density in autistic children than in controls. That means were there less brain cells in regions associated with memory, learning, reasoning and problem-solving.

On the other hand, the study found that the brains of autistic children had higher neuron density in the amygdala. A part of the brain’s limbic system, the amygdala is a small but critical structure with multiple functions. The amygdala processes emotions, and connects those emotions to tasks like learning, memory formation, and sensory processing. It’s also the home of the fight or flight response."

They also talk about how this doesnt mean a whole lot because autistics were faster at problem solving in previous studys.