biostudies-literatureUnknown59(10)Molina-Rodriguez SFunctional near-infrared spectroscopy (fNIRS) is an increasingly used technology for imaging neural correlates of cognitive processes. However, fNIRS signals are commonly impaired by task-evoked and spontaneous hemodynamic oscillations of non-cerebral origin, a major challenge in fNIRS research. In an attempt to isolate the task-evoked cortical response, we investigated the coupling between hemodynamic changes arising from superficial and deep layers during mental effort. For this aim, we applied a rhythmic mental arithmetic task to induce cyclic hemodynamic fluctuations suitable for effective frequency-resolved measurements. Twenty university students aged 18-25 years (eight males) underwent the task while hemodynamic changes were monitored in the forehead using a newly developed NIRS devPsychophysiologye14063https://www.ebi.ac.uk/biostudies/studies/S-EPMC9540762biostudies-literatureFrequency-domain analysis of fNIRS fluctuations induced by rhythmic mental arithmetic.PMC9540762Molina-Rodriguez SMirete-Fructuoso MIbanez-Ballesteros JMartinez LMfalseFrequency-domain analysis of fNIRS fluctuations induced by rhythmic mental arithmetic.Functional near-infrared spectroscopy (fNIRS) is an increasingly used technology for imaging neural correlates of cognitive processes. However, fNIRS signals are commonly impaired by task-evoked and spontaneous hemodynamic oscillations of non-cerebral origin, a major challenge in fNIRS research. In an attempt to isolate the task-evoked cortical response, we investigated the coupling between hemodynamic changes arising from superficial and deep layers during mental effort. For this aim, we applied a rhythmic mental arithmetic task to induce cyclic hemodynamic fluctuations suitable for effective frequency-resolved measurements. Twenty university students aged 18-25 years (eight males) underwent the task while hemodynamic changes were monitored in the forehead using a newly developed NIRS dev2022-01-01T00:00:00Z2022 Oct2025-04-04T20:03:59.985Z2025-04-04T20:03:59.985ZS-EPMC95407623539407510.1111/psyp.14063