{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,5]],"date-time":"2026-02-05T08:57:16Z","timestamp":1770281836973,"version":"3.49.0"},"reference-count":47,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,4,28]],"date-time":"2025-04-28T00:00:00Z","timestamp":1745798400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Call CNPq\/MCTI\/FNDCT N\u00ba 18\/2021 and Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES)","award":["CODE001"],"award-info":[{"award-number":["CODE001"]}]},{"name":"Santos Dumont Institute (ISD)","award":["CODE001"],"award-info":[{"award-number":["CODE001"]}]},{"name":"Ministry of Education (MEC)","award":["CODE001"],"award-info":[{"award-number":["CODE001"]}]},{"name":"Financiadora de Estudos e Projetos (Finep)","award":["CODE001"],"award-info":[{"award-number":["CODE001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Brain Sciences"],"abstract":"<jats:p>Simultaneous eye tracking and cerebral hemodynamic monitoring contribute to the understanding of neural responses to stimuli in infants. However, exploring the impact of complex socioeconomic and environmental adversities on neurodevelopment requires transitioning this tool from research laboratories into clinical practice to evaluate its feasibility in outpatient contexts. Background\/Objectives: This study aimed to present a protocol for simultaneously integrating functional near-infrared spectroscopy (fNIRS) with eye tracking (ET) in infants at risk for neurodevelopmental disorders in a clinical setting with limited resources, during a cognitive task. Methods:The protocol was applied to infants in their first 12 months of life. The infants were exposed to tasks involving the processing of social and non-social stimuli, while their brain signals were monitored using fNIRS and their eyes were tracked with ET. The protocol included three main stages: (1) pre-collection, involving the preparation and habituation of the infants and equipment setup (fNIRS and ET); (2) cognitive function monitoring, using social and non-social stimuli to assess preferential processing via fNIRS and ET; and (3) post-collection, with guidelines for data pre-processing and analysis. Results: The application of the protocol allowed for the identification of technical challenges and the adaptation of procedures for clinical use. The main methodological challenges were difficulty using the conventional cap, excessive movement, synchronization issues between fNIRS and ET, and difficulties calibrating both devices across different age groups. Conclusions: The standardization proposed in this protocol enables healthcare professionals to explore different neurocognitive aspects in pediatric clinical settings and expands the scope of neurodevelopmental assessments.<\/jats:p>","DOI":"10.3390\/brainsci15050469","type":"journal-article","created":{"date-parts":[[2025,4,29]],"date-time":"2025-04-29T09:00:39Z","timestamp":1745917239000},"page":"469","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Simultaneous Eye Tracking and Cerebral Hemodynamic Monitoring in Infants: A Guide for Pediatric Outpatient Follow-Up"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5973-0890","authenticated-orcid":false,"given":"Val\u00e9ria Azevedo","family":"de Almeida","sequence":"first","affiliation":[{"name":"Alberto Santos Dumont Institute of Education and Research (ISD), RN, Maca\u00edba CEP 59288-899, Brazil"},{"name":"Physiotherapy Department, Federal University of Rio Grande do Norte, RN, Natal CEP 59078-970, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5882-0712","authenticated-orcid":false,"given":"Maria Clara Lima","family":"da Cruz","sequence":"additional","affiliation":[{"name":"Alberto Santos Dumont Institute of Education and Research (ISD), RN, Maca\u00edba CEP 59288-899, Brazil"},{"name":"Physiotherapy Department, Federal University of Rio Grande do Norte, RN, Natal CEP 59078-970, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nicole Rodrigues","family":"Morais","sequence":"additional","affiliation":[{"name":"Physiotherapy Department, Federal University of Rio Grande do Norte, RN, Natal CEP 59078-970, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Italo Vinicius Tavares","family":"Rodrigues","sequence":"additional","affiliation":[{"name":"Physiotherapy Department, Federal University of Rio Grande do Norte, RN, Natal CEP 59078-970, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2441-5991","authenticated-orcid":false,"given":"Cintia Ricaele Ferreira da","family":"Silva","sequence":"additional","affiliation":[{"name":"Physiotherapy Department, Federal University of Rio Grande do Norte, RN, Natal CEP 59078-970, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0954-5317","authenticated-orcid":false,"given":"Edgard","family":"Morya","sequence":"additional","affiliation":[{"name":"Alberto Santos Dumont Institute of Education and Research (ISD), RN, Maca\u00edba CEP 59288-899, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Silvana Alves","family":"Pereira","sequence":"additional","affiliation":[{"name":"Physiotherapy Department, Federal University of Rio Grande do Norte, RN, Natal CEP 59078-970, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,28]]},"reference":[{"key":"ref_1","first-page":"45","article-title":"The Impact of Early Childhood Adversity on Neurodevelopment: A Comprehensive Review","volume":"11","year":"2024","journal-title":"J. Neurobehav. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4130","DOI":"10.1002\/hbm.24690","article-title":"Longitudinal associations between white matter maturation and cognitive development across early childhood","volume":"40","author":"Dai","year":"2019","journal-title":"Hum. Brain Mapp."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Anaya, B., Ostlund, B., LoBue, V., Buss, K., and P\u00e9rez-Edgar, K. (2021). Psychometric properties of infant electroencephalography: Developmental stability, reliability, and construct validity of frontal alpha asymmetry and delta\u2013beta coupling. Dev. Psychobiol., 63.","DOI":"10.1002\/dev.22178"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1080\/21622965.2020.1768392","article-title":"Neural and psychophysiological correlates of social communication development: Evidence from sensory processing, motor, cognitive, language and emotional behavioral milestones across infancy","volume":"11","author":"Cruz","year":"2022","journal-title":"Appl. Neuropsychol. Child."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1113","DOI":"10.12688\/gatesopenres.12951.2","article-title":"Implementing neuroimaging and eye tracking methods to assess neurocognitive development of young infants in low- and middle-income countries","volume":"3","author":"Katus","year":"2019","journal-title":"Gates Open Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"100882","DOI":"10.1016\/j.dcn.2020.100882","article-title":"Neural responses to happy, fearful and angry faces of varying identities in 5-and 7-month-old infants","volume":"47","author":"Bayet","year":"2021","journal-title":"Dev. Cogn. Neurosci."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"da Silva Soares, R., Ambriola Oku, A.Y., Barreto, C.S., and Ricardo Sato, J. (2022). Applying functional near-infrared spectroscopy and eye-tracking in a naturalistic educational environment to investigate physiological aspects that underlie the cognitive effort of children during mental rotation tests. Front. Hum. Neurosci., 16.","DOI":"10.3389\/fnhum.2022.889806"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1016\/j.rpped.2015.03.003","article-title":"Near-infrared spectroscopy as an auxiliary tool in the study of child development","volume":"33","author":"Oliveira","year":"2015","journal-title":"Rev. Paul. Pediatr."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.neures.2020.11.003","article-title":"Applications of functional near-infrared spectroscopy (fNIRS) in neonates","volume":"170","author":"Peng","year":"2021","journal-title":"Neurosci. Res."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1111\/j.1532-7078.2011.00097.x","article-title":"Infant eyes: A window on cognitive development","volume":"17","author":"Aslin","year":"2012","journal-title":"Infancy"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Cristia, A., Dupoux, E., Hakuno, Y., Lloyd-Fox, S., Schuetze, M., Kivits, J., Bergvelt, T., van Gelder, M., Filippin, L., and Charron, L. (2013). Um banco de dados online de estudos de espectroscopia funcional no infravermelho pr\u00f3ximo em beb\u00eas: Uma revis\u00e3o sistem\u00e1tica ampliada pela comunidade. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0058906"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Lloyd-Fox, S., Papademetriou, M., Darboe, M.K., Everdell, N.L., Wegmuller, R., Prentice, A.M., Moore, S.E., and Elwell, C.E. (2014). Functional near infrared spectroscopy (fNIRS) to assess cognitive function in infants in rural Africa. Sci. Rep., 4.","DOI":"10.1038\/srep04740"},{"key":"ref_13","unstructured":"Ringwalt, S. (2008). Developmental Screening and Assessment Instruments with an Emphasis on Social and Emotional Development for Young Children Ages Birth through Five. National Early Childhood Technical Assistance Center (NECTAC), Frank Porter Graham Child Development Institute."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/j.tics.2005.01.003","article-title":"Methodological challenges for understanding cognitive development in infants","volume":"9","author":"Aslin","year":"2005","journal-title":"Trends Cogn. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.cobme.2017.09.011","article-title":"Functional near infrared spectroscopy: Enabling routine functional brain imaging","volume":"4","author":"Selb","year":"2017","journal-title":"Curr. Opin. Biomed. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1111\/nyas.13948","article-title":"The present and future use of functional near-infrared spectroscopy (fNIRS) for cognitive neuroscience","volume":"1464","author":"Pinti","year":"2020","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"101125","DOI":"10.1016\/j.dcn.2022.101125","article-title":"Association of psychosocial adversity and social information processing in children raised in a low-resource setting: An fNIRS study","volume":"56","author":"Pirazzoli","year":"2022","journal-title":"Dev. Cogn. Neurosci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"986","DOI":"10.1111\/j.1467-8624.2009.01312.x","article-title":"Social perception in childhood: A near infrared spectroscopy study","volume":"80","author":"Blasi","year":"2009","journal-title":"Child Dev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1136\/archdischild-2016-310525","article-title":"Eye-tracking-based assessment of cognitive function in low-resource settings","volume":"102","author":"Forssman","year":"2017","journal-title":"Arch. Dis. Child."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1016\/S1364-6613(99)01418-7","article-title":"Saccadic eye movements and cognition","volume":"4","author":"Liversedge","year":"2000","journal-title":"Trends Cogn. Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1016\/j.neuropsychologia.2008.07.016","article-title":"Eye-movements reveal attention to social information in autism spectrum disorder","volume":"47","author":"Leekam","year":"2009","journal-title":"Neuropsychologia"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1016\/j.trf.2022.11.013","article-title":"Cognitive load, working memory capacity and driving performance: A preliminary fNIRS and eye tracking study","volume":"92","author":"Broadbent","year":"2023","journal-title":"Transp. Res. Part F Traffic Psychol. Behav."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"168","DOI":"10.5935\/1980-6906\/psicologia.v20n1p179-188","article-title":"Rastreamento ocular: Possibilidades e desafios do uso da tecnologia em amostras infantis","volume":"20","author":"Balam","year":"2018","journal-title":"Rev. Psicol. Teor. E Pr\u00e1tica"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Piazza, C., Bacchetta, A., Crippa, A., Mauri, M., Grazioli, S., Reni, G., Nobile, M., and Bianchi, A.M. (2019, January 26\u201328). Preprocessing pipeline for fNIRS data in children. Proceedings of the XV Mediterranean Conference on Medical and Biological Engineering and Computing\u2013MEDICON 2019: Proceedings of MEDICON 2019, Coimbra, Portugal.","DOI":"10.1007\/978-3-030-31635-8_28"},{"key":"ref_25","unstructured":"Filippetti, M.L., Andreu-Perez, J., De Klerk, C., Richmond, C., and Rigato, S. (2022). Are advanced methods necessary to improve infant fNIRS data analysis? An assessment of baseline-corrected averaging, general linear model (GLM) and multivariate pattern analysis (MVPA) based approaches. arXiv."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2158244018784993","DOI":"10.1177\/2158244018784993","article-title":"Infants\u2019 visual preferences for prosocial behavior and other-race characters at 6 months: An eye-tracking study","volume":"8","author":"Holvoet","year":"2018","journal-title":"Sage Open"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1111\/cdep.12180","article-title":"Using eye tracking to understand infants\u2019 attentional bias for faces","volume":"10","year":"2016","journal-title":"Child Dev. Perspect."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1016\/j.ntt.2012.06.003","article-title":"Measuring infant memory: Utility of the visual paired-comparison test paradigm for studies in developmental neurotoxicology","volume":"34","author":"Burbacher","year":"2012","journal-title":"Neurotoxicol. Teratol."},{"key":"ref_29","first-page":"e59581","article-title":"Exploring infant sensitivity to visual language using eye tracking and the preferential looking paradigm","volume":"15","author":"Stone","year":"2019","journal-title":"J. Vis. Exp. (JoVE)"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1111\/sjop.12002","article-title":"Eye tracking infants: Investigating the role of attention during learning on recognition memory","volume":"54","author":"Taylor","year":"2013","journal-title":"Scand. J. Psychol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"023519","DOI":"10.1117\/1.NPh.10.2.023519","article-title":"Using functional near-infrared spectroscopy to study the early developing brain: Future directions and new challenges","volume":"10","author":"Gervain","year":"2023","journal-title":"Neurophotonics"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"031415","DOI":"10.1117\/1.NPh.3.3.031415","article-title":"Methodology for high-yield acquisition of functional near-infrared spectroscopy data from alert, upright infants","volume":"3","author":"Goodwin","year":"2016","journal-title":"Neurophotonics"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"599","DOI":"10.1111\/aos.13038","article-title":"Quantification of visual function assessment using remote eye tracking in children: Validity and applicability","volume":"94","author":"Kooiker","year":"2016","journal-title":"Acta Ophthalmol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/j.cortex.2018.05.002","article-title":"Eye contact modulates facial mimicry in 4-month-old infants: An EMG and fNIRS study","volume":"106","author":"Hamilton","year":"2018","journal-title":"Cortex"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1536","DOI":"10.1016\/j.neuroimage.2010.01.068","article-title":"General to specific development of functional activation in the cerebral cortexes of 2-to 3-month-old infants","volume":"50","author":"Watanabe","year":"2010","journal-title":"Neuroimage"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"446","DOI":"10.1016\/j.neuroimage.2013.10.027","article-title":"MNE software for processing MEG and EEG data","volume":"86","author":"Gramfort","year":"2014","journal-title":"NeuroImage"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Emberson, L.L., Zinszer, B.D., Raizada, R.D.S., and Aslin, R.N. (2017). Decoding the infant mind: Multivariate pattern analysis (MVPA) using fNIRS. PLoS ONE, 12.","DOI":"10.1371\/journal.pone.0172500"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1016\/S0140-6736(86)90837-8","article-title":"Statistical methods for assessing agreement between two methods of clinical measurement","volume":"327","author":"Bland","year":"1986","journal-title":"Lancet"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Ross-Sheehy, S., Reynolds, E., and Eschman, B. (2020). Evidence for attentional phenotypes in infancy and their role in visual cognitive performance. Brain Sci., 10.","DOI":"10.3390\/brainsci10090605"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"988","DOI":"10.1080\/02699931.2017.1374242","article-title":"The effects of emotion regulation strategies on positive and negative affect in early adolescents","volume":"32","author":"Wante","year":"2018","journal-title":"Cogn. Emot."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Witmer, J.S., Aeschlimann, E.A., Metz, A.J., Troche, S.J., and Rammsayer, T.H. (2018). Functional near-infrared spectroscopy recordings of visuospatial working memory processes. Part II: A replication study in children on sensitivity and mental-ability-induced differences in functional activation. Brain Sci., 8.","DOI":"10.3390\/brainsci8080152"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Xu, S.Y., Lu, F.M., Wang, M.Y., Hu, Z.S., Zhang, J., Chen, Z.Y., Armada-da-Silva, P.A.S., and Yuan, Z. (2020). Altered functional connectivity in the motor and prefrontal cortex for children with Down\u2019s syndrome: An fNIRS study. Front. Hum. Neurosci., 14.","DOI":"10.3389\/fnhum.2020.00006"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Di Lorenzo, R., Blasi, A., Junge, C., Van den Boomen, C., Van Rooijen, R., and Kemner, C. (2019). Brain responses to faces and facial expressions in 5-month-olds: An fNIRS study. Front. Psychol., 10.","DOI":"10.3389\/fpsyg.2019.01240"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"023517","DOI":"10.1117\/1.NPh.10.2.023517","article-title":"Functional near-infrared spectroscopy in pediatric clinical research: Different pathophysiologies and promising clinical applications","volume":"10","author":"Gallagher","year":"2023","journal-title":"Neurophotonics"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Poliakova, E., Conrad, A.L., Schieltz, K.M., and O\u2019Brien, M.J. (2023). Using fNIRS to evaluate ADHD medication effects on neuronal activity: A systematic literature review. Front. Neuroimaging, 2.","DOI":"10.3389\/fnimg.2023.1083036"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/j.dcn.2016.11.005","article-title":"Cortical specialisation to social stimuli from the first days to the second year of life: A rural Gambian cohort","volume":"25","author":"Begus","year":"2017","journal-title":"Dev. Cogn. Neurosci."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Sato, J.R., Pereira, T.D., Martins, C.M.d.L., Bezerra, T.A., Queiroz, M.E., Costa, L.P., Andrade, S.M., and Biazoli, C.E. (2023). A Novel Exploratory Graph-Based Analytical Tool for Functional Near-Infrared Spectroscopy in Naturalistic Experiments: An Illustrative Application in Typically Developing Children. Brain Sci., 13.","DOI":"10.3390\/brainsci13060905"}],"container-title":["Brain Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3425\/15\/5\/469\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:23:23Z","timestamp":1760030603000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3425\/15\/5\/469"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,28]]},"references-count":47,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2025,5]]}},"alternative-id":["brainsci15050469"],"URL":"https:\/\/doi.org\/10.3390\/brainsci15050469","relation":{},"ISSN":["2076-3425"],"issn-type":[{"value":"2076-3425","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,4,28]]}}}