“…Researchers studying children's development (Noreika et al, 2020 ; Turk et al, 2022 ) and spoken communication (Kelsen et al, 2022 ) have also signaled that longitudinal hyperscanning could advance their research. Moreover, others suggest that fNIRS would be a suitable technique to address the lack of longitudinal data pertaining to the development of cognition in infants and children (Miguel et al, 2019 ; Sato et al, 2021 ), neurodegenerative diseases (Bonilauri et al, 2020 ; Srinivasan et al, 2023 ), psychiatric disorders (Kumar et al, 2017 ; Ho et al, 2020 ), hearing after receiving a cochlear implant (McKay et al, 2015 ; Anderson C. A. et al, 2017 ; Zhou et al, 2022 ), and use of psychedelic substances (Scholkmann and Vollenweider, 2022 ). While these authors do not explicitly refer to hyperscanning as their technique of choice, INS recorded with fNIRS over multiple sessions could address several methodological aspirations (i.e., ecological validity, two-brain design, longitudinal assessment) at once.…”