Title: Using broadband near-infrared spectroscopy to measure the functioning of the social brain in infancy
Funder: Economic and Social Research Council

Abstract: During my PhD, I developed the world's first system to simultaneously record both spatial and temporal aspects of brain function in infants and toddlers. This system combines three techniques: (a) functional near-infrared spectroscopy (fNIRS), used to measure changes in blood flow that occur after a brain region becomes active, (b) broadband near-infrared spectroscopy (bNIRS), which measures changes that occur within the 'powerhouse' (mitochondria) of the cell and (c) electroencephalography (EEG), which is sensitive to the coordinated activity of large groups of neurons. During my PhD I demonstrated that this combined system can be used to measure the functioning of the social brain, and may be sensitive to alterations in social brain functioning in infants with an elevated risk for autism. With this ESRC Postdoctoral Fellowship, I aim to build on the work that I began during my PhD to forge a new line of research and have identified four main objectives of this Fellowship. 1. Data analysis and publications One of the most novel aspects of my PhD work was creating a combined system that used both NIRS and EEG simultaneously. To date, in infants, no data analysis pipeline exists that combines both measures to obtain a full understanding of brain function in early infancy. During this Fellowship, I aim to develop a data analysis pipeline to combine both measures. This will additionally help foster collaborations with other research groups, such as with researchers at the Centre for the Developing Brain at King's College London. I will analyse this data and produce one to two publications on social brain function in infancy. 2. Further data collection During my PhD, I used the combined system to measure brain activity in infants at high familial risk for autism. The results indicated that early changes in the functioning of the social brain could be detected using this combined technique. However, the sample size consisted only of a few infants. During this Fellowship, therefore, I am aim to collect further data on a larger sample of infants. This is critical for bringing this multidisciplinary body of work to completion which will generate a number of significant outputs to the wide scientific community. Moreover, this work will enable me to publish another paper comparing the low- risk and high-risk autism infants. 3. Develop grant proposals Completing the aforementioned aims 1) and 2) will put me in a strong position to apply for further research fellowship schemes such as those offered by the Wellcome Trust and the MRC and to apply for awards such as the SFARI Explorer and Pilot Awards. These will enable me to obtain further funding to use this combined system investigate brain function in many other contexts. 4. Public engagement The public engagement component will be in collaboration with the UCL Multimodal Spectroscopy group, which has launched a public engagement project - Metabolight (www.metabolight.org), funded by the Wellcome Trust. I intend to collaborate with engineers from Metabolight in order to organize an event for families from a diverse range of socioeconomic backgrounds. Currently, the field of infant research is biased towards families with higher socioeconomic status (SES) and higher levels of education. The purpose of this event is to target families from a diverse range of socioeconomic backgrounds in order to help parents gain hands-on understanding of scientific research, to understand the engineering behind the tools used to measure brain activity and to encourage them to participate in scientific research with their children.

Lay abstract: Over the first five years of life, infants transition from being passive recipients of care to active shapers of their social world. Over this time, they develop and deploy a broad range of social skills that include language, imitation, empathy, cooperation, turn-taking, and imaginative play. How do they do this? Whilst we have mapped the behavioral development of these skills in exquisite detail, our understanding of the changes in the brain that underpin their development is in its infancy. This is important because disruptions in social brain development are implicated in disorders like autism, shyness, and anxiety. Our progress has been limited by the methods we have employed. Traditional brain imaging methods such as functional magnetic resonance imaging (fMRI) can only be used in young, sleeping infants while electroencephalography (EEG) is only sensitive to temporal but not spatial aspects of brain activity. Our understanding of social brain development has thus far often focused on the processing of static faces in young infants, a long way from the sophisticated behaviors that toddlers develop. To move forward, a new way of measuring holistic brain responses needs to be developed, in naturalistic contexts from infancy to toddlerhood. With this ESRC Fellowship, I intend to extend the work that I started during my Ph.D. in order to develop a new way to measure brain responses. More specifically, I developed and tested the use of a novel system to record multiple aspects of brain function simultaneously. Namely, it combines functional near-infrared spectroscopy (fNIRS) to measure changes in blood flow to specific brain regions, broadband near-infrared spectroscopy (bNIRS) to measure cellular changes occurring within the mitochondria of cells and EEG to measure temporally accurate, coordinated activity of large groups of neurons. I demonstrated that this system could be used to obtain measures of activity in the social brain in both infants at high and low- risk for autism. During this Fellowship, I aim to a) Develop an advanced data analysis pipeline in order to combine all the measures from this system to obtain a holistic understanding of the functioning of the social brain. Following this, I aim to write papers to disseminate this research to the scientific community. b) To collect data using this system on a larger sample of infants at high-risk for autism. c) Develop grant proposals for further funding to allow integration of this system into a number of different research projects investigating complex brain mechanisms. d) To disseminate this research to the public by organising a public engagement event.

Research activity codes: 1.1 NORMAL BIOLOGICAL DEVELOPMENT AND FUNCTIONING;2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: NEUROLOGICAL;MENTAL HEALTH