Most of the infants born to HIV-positive mothers are HIV-exposed but uninfected. HIV exposure in infants may cause brain developmental delays. This study will look for changes in the brain that might have occurred due to HIV exposure in infants. These measurements can lead to novel insights regarding the impact of HIV exposure in infants' brain and potentially guide the development of new therapies to mitigate abnormal brain development.

The purpose of this study is to understand how children's brains process sounds and language. Children with Autism Spectrum Disorder (ASD), Intellectual and Developmental Delay (IDD), or Developmental Language Disorder (DLD) often have trouble understanding sounds that are too close together compared to Typically Developing Controls (children without ASD, IDD, or DLD). Fast changes in speech can be hard for children. This may be awkward during conversations and difficult in social situations. This research will see if trouble with processing sounds contributes to language difficulties in children with ASD, IDD, and/or DLD.

HIV infection can cause harm to the brain and negatively affect memory, learning, and decision making in daily activities. Smoking may affect the ability of medications to reduce HIV in the bloodstream (viral load), which may affect long-term survival and brain health. This study will look for changes in the brain that might have occurred due to HIV infection or smoking.