Background:

- Near-infrared spectroscopy (NIRS) is a functional imaging technique that can be uses light to study brain function while allowing for movement. To look at blood flow in the brain, NIRS uses a low-power light source with detectors that see how the light changes as it passes through brain tissue. Brain blood flow can indicate which parts of the brain are active during different tasks. Researchers want to study children with attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD) and will use NIRS to compare the blood flow in the brain of children with ADHD and ASD with that of typically developing children.

Objectives:

• To see how well NIRS can detect changes in brain blood flow during tests of thinking and memory in children.
• To compare blood flow in the brains of typically developing children and those with ADHD or ASD.

Eligibility:

- Children between 4 and 8 years of age with ASD, ADHD, or children with no psychiatric diagnoses.

Design:

• Participants will be screened for eligibility. Those who are taking stimulant medication for ADHD or ASD will need to stop taking it for 3 days before the study visit.
• After participating in a screening assessment, all participants will have one study visit. At this visit, they will have be asked to complete two tasks during a NIRS scan. For both tasks, they will react to images on a computer screen. This visit will last about 2 hours.
• This is a testing study only. No blood or other samples will be needed for this study.

Objective: to test whether Near Infra-Red Spectroscopy (NIRS) can be used to monitor cognitive brain function and detect markers for differentiation of Autism Spectrum Disorders (ASD) and Attention Deficit Hyperactivity Disorder (ADHD).

Study population: Children with ASD, ADHD, and typically developing children, all between 4 and 8 years of age.

Design: The study will investigate NIRS signal changes while children with ASD, ADHD, and typically developing children perform well-known functional tasks.

Outcome Measures: Graded changes in blood flow and oxygen, measured with NIRS, in response to different functional tasks.

• INCLUSION CRITERIA:

Children will be between 4 to 8 years of age (4 years, 0 months to 8 years, 11 months). English speakers only will be recruited for the study, because the language measures/tests and stimuli being used are in English and were developed and standardized on English-only samples.

Typically Developing Group:

-Development in nonverbal and verbal areas within age expectations (per scores onthe Differential Ability Scales, Second Edition or the Wechsler Preschool and Primary Scale of Intelligence Fourth Edition , no more than 1.5 standard deviation below the mean)

ASD Group:

-Diagnosis of Autistic Disorder, Asperger s disorder, or Pervasive Developmental Disorder - Not Otherwise Specified (PDD NOS), based on diagnostic evaluation conducted through a separate screening protocol

ADHD Group:

-Diagnosis of ADHD based on diagnostic evaluation conducted through a separate screening protocol Minimum Nonverbal IQ of 80; Minimum Verbal IQ score of 60

EXCLUSION CRITERIA:

All children who meet the following criteria:

• Primary language spoken at home is other than English
• Any skin disease that affects the scalp
• Past or present vascular disease, such as lupus, ankylosing spondylitis or scleroderma.
• Known adverse reaction to latex
• Presence or history of medical conditions known to affect cerebral anatomy, such as known cysts, arterivenous malformations or cortical tubers.
• Head trauma with loss of consciousness lasting longer than 5 seconds in the last year or any evidence of functional impairment due to and persisting after head trauma
• Motor movement disorder which may cause sudden excessive movement, such as Tourette s disorder
• Birth before 32 weeks of gestation. Premature birth can have a profound effect on brain function and structure
• A known neurological or neurogenetic condition affecting the central nervous system, such as epilepsy, cerebral palsy, neurofibromatosis, velo-cardiofacial syndrome.
• Color blindness

Typically Developing Group:

• Cognitive impairment, defined as Nonverbal IQ below 80, or signs of ASD or ADHD
• Confirmed diagnosis of any DSM-IV-TR Axis I disorder
• Taking medications for neuropsychiatric disorders such as antidepressants, antipsychotics, mood stabilizers, anxiolytics or any medication used to treat ADHD (psychostimulants, atomoxetine (Strattera ), bupropion (Wellbutrin ), tricyclic antidepressants (like impramine), clonidine, guanfacine, or modafinil (Provigil ).

ASD Group:

• Taking medications for neuropsychiatric disorders: such as antidepressants, antipsychotics, mood stabilizers, or anxiolytics. Some medications used to treatment for ADHD are also exclusionary for all children - including atomoxetine (Strattera ), bupropion (Wellbutrin ), tricyclic antidepressants (like impramine), clonidine, guanfacine, or modafinil (Provigil ). Children with ASD who take stimulants (like Ritalin, adderall, concerta and vyvanse) may be able to participate if they are willing and able to stop stimulant medications for 2 days on 1 occasion for the study
• A known neurological or neurogenetic condition affecting the central nervous system, such as epilepsy, cerebral palsy, neurofibromatosis, velo-cardiofacial syndrome.

ADHD Group:

• Taking medications for neuropsychiatric disorders: such as antidepressants, antipsychotics, mood stabilizers, or anxiolytics. Some medications used to treatment for ADHD are also exclusionary for all children - including atomoxetine (Strattera ), bupropion (Wellbutrin ), tricyclic antidepressants (like impramine), clonidine, guanfacine, or modafinil (Provigil ). Children with ASD who take stimulants (like Ritalin, adderall, concerta and vyvanse) may be able to participate if they are willing and able to stop stimulant medications for 2 days on 1 occasion for the study
• Other psychiatric diagnoses (including ASD, anxiety and depression), except for comorbid oppostional defiant disorder