Abnormal selective attention normalizes P3 amplitudes in PDD.

Giallo et al. (2006) compared brain waves in kids and teens with pervasive developmental disorder (PDD) to typically developing peers.

They measured the P3 wave, a spike that shows the brain just noticed something important.

All children sat quietly while odd tones popped up among regular tones.

Younger children with PDD had smaller P3 spikes than controls.

Surprisingly, adolescents with PDD showed normal-sized P3 spikes.

Their earlier selective-attention waves looked odd, hinting the teens used a different brain route to reach the same endpoint.

Anthony et al. (2020) saw smaller early brain waves in ASD children, seeming to clash with the teen normalization here. The gap is age: early sensory gaps may close or be patched by attention tricks as kids grow.

Chien et al. (2018) later found shorter P3a timing in older youth with ASD, extending this idea that the P3 family keeps changing with age.

Zigler et al. (1989) first reported smaller P3b in autism, giving a baseline that shows the 2006 teen data as a possible developmental update, not a fixed deficit.

If you test teens with ASD, a "normal" P3 does not guarantee typical processing. Ask yourself what compensatory path they took. Pair brain checks with real-world attention probes. Track the same client over years; an early flat P3 can bloom later, guiding when to boost or fade supports.