The investigators have previously shown that the administration of low-level infrared light is a safe and non-invasive procedure which improves cognition and emotion, as well as enhances brain metabolic activity. Based on previous studies, the investigators hypothesize that this methodology, called low-level light therapy or photobiomodulation, could be used to improve behavioral symptoms in individuals with autism spectrum disorder (ASD).

The Gonzalez-Lima Laboratory at the University of Texas at Austin will be recruiting participants for a study investigating whether transcranial infrared light stimulation, or TILS, is beneficial for people diagnosed with autism spectrum disorder (ASD).

The molecular target of TILS is cytochrome c oxidase, a mitochondrial enzyme which is crucial for oxygen utilization. People with ASD show impaired mitochondrial function (Siddiqui, Elwell, and Johnson, 2016), as well as alterations in the prefrontal cortex (Amaral, Schumann, and Nordahl, 2008), which plays a key neurological role in mediating attention, impulse control, and social cognition functions.

The lab has previously shown that TILS, delivered to the prefrontal cortex, can be used to improve cognitive functions such as attention (Barrett and Gonzalez-Lima, 2013), executive function (Blanco, Maddox, and Gonzalez-Lima, 2017), and emotional regulation (Zaizar, Papini, Gonzalez-Lima, and Telch, 2021). This cognitive enhancement from TILS is accompanied by an increase in oxygenation of the prefrontal cortex (Holmes, Barrett, Saucedo, O'Connor, Liu, and Gonzalez-Lima, 2019). Recently, the beneficial effects of TILS on ASD symptoms have been safely explored in adults (Ceranoglu et al., 2022) and children/adolescents (Pallanti et al., 2022).

The goal of the study is to recruit children, adolescents, and adults, either ASD or non-ASD, for a study of the effects of repeated administration of TILS on autistic behavior. Participants will be asked to give informed consent, complete a series of questionnaires and cognitive tests, and wear a headband to non-invasively monitor brain activity using near-infrared spectroscopy. TILS is administered non-invasively with a headband device that uses light-emitting diodes (LEDs), which are cleared as safe for use in humans by the Food and Drug Administration (FDA), but the device has not been approved by the FDA for the specific investigational use in this research. The study will train participants (or caregivers) on how to use the LED device, then send the participants home to use the LED device. The investigators will contact participants once a week to check progress. At the end of the study, participants return for the same assessments, at which time the participants will return the LED device.

Inclusion Criteria:

• Age between 4-60 years

Exclusion Criteria:

• Current pregnancy

What data will be shared? Individual participant data that underlie the results reported in this study, after deidentification (text, tables, figures, and appendices).

A data dictionary, including a description of the variables and types of data, collected for each individual, will be provided. This data will include anonymized individual participant demographic information and all outcome variables (cognitive task data, spectroscopy data).

Beginning 9 months and ending 36 months following article publication.

The raw data will be made available by the researchers upon reasonable request by any qualified doctoral researcher (PhD, MD). They will be granted access by contacting the corresponding author/principal investigator (F. Gonzalez-Lima, utbrainproject@gmail.com).

It will be made available to qualified researchers whose proposed use of the data has been approved by an independent review committee (Institutional Review Board) identified for the purpose of individual participant data meta-analysis.

Proposals may be submitted up to 36 months following article publication. After 36 months, the data will be available in our University's shared network drive, but without investigator support other than deposited metadata.