Prefrontal cortex activation upon a demanding virtual hand-controlled task: A new frontier for neuroergonomics

open9noFunctional near-infrared spectroscopy (fNIRS) is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR) real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC) in subjects while performing a demanding VR hand-controlled task (HCT). Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3-dimensional (3D) hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB) over a virtual route (VROU) reproducing a 42 m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2 ± 37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found between the distance traveled by the guided VB and the corresponding cortical activation. These results confirm the suitability of fNIRS technology to objectively evaluate cortical hemodynamic changes occurring in VR environments. Future studies could give a contribution to a better understanding of the cognitive mechanisms underlying human performance either in expert or non-expert operators during the simulation of different demanding/fatiguing activities.openCarrieri, Marika; Petracca, Andrea; Lancia, Stefania; Basso Moro, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, ValentinaCarrieri, Marika; Petracca, Andrea; Lancia, Stefania; BASSO MORO, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentin

Long-term continuous monitoring of the preterm brain with diffuse optical tomography and electroencephalography: A technical note on cap manufacturing

open12noDiffuse optical tomography (DOT) has recently proved useful for detecting whole-brain oxygenation changes in preterm and term newborns' brains. The data recording phase in prior explorations was limited up to a maximum of a couple of hours, a time dictated by the need to minimize skin damage caused by the protracted contact with optode holders and interference with concomitant clinical/nursing procedures. In an attempt to extend the data recording phase, we developed a new custom-made cap for multimodal DOT and electroencephalography acquisitions for the neonatal population. The cap was tested on a preterm neonate (28 weeks gestation) for a 7-day continuous monitoring period. The cap was well tolerated by the neonate, who did not suffer any evident discomfort and/or skin damage. Montage and data acquisition using our cap was operated by an attending nurse with no difficulty. DOT data quality was remarkable, with an average of 92% of reliable channels, characterized by the clear presence of the heartbeat in most of them.openopenAlfonso Galderisi; Sabrina Brigadoi; Simone Cutini; Sara Basso Moro; Elisabetta Lolli; Federica Meconi; Silvia Benavides-Varela; Eugenio Baraldi; Piero Amodio; Claudio Cobelli; Daniele Trevisanuto; Roberto Dell'AcquaGalderisi, Alfonso; Brigadoi, Sabrina; Cutini, Simone; BASSO MORO, Sara; Lolli, Elisabetta; Meconi, Federica; Silvia, Benavides-Varela; Baraldi, Eugenio; Amodio, Piero; Cobelli, Claudio; Trevisanuto, Daniele; Dell'Acqua, Robert

Concurrent fNIRS and EEG for brain function investigation: A systematic, methodology-focused review

Electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) stand as state-of-the-art techniques for non-invasive functional neuroimaging. On a unimodal basis, EEG has poor spatial resolution while presenting high temporal resolution. In contrast, fNIRS offers better spatial resolution, though it is constrained by its poor temporal resolution. One important merit shared by the EEG and fNIRS is that both modalities have favorable portability and could be integrated into a compatible experimental setup, providing a compelling ground for the development of a multimodal fNIRS-EEG integration analysis approach. Despite a growing number of studies using concurrent fNIRS-EEG designs reported in recent years, the methodological reference of past studies remains unclear. To fill this knowledge gap, this review critically summarizes the status of analysis methods currently used in concurrent fNIRS-EEG studies, providing an up-to-date overview and guideline for future projects to conduct concurrent fNIRS-EEG studies. A literature search was conducted using PubMed and Web of Science through 31 August 2021. After screening and qualification assessment, 92 studies involving concurrent fNIRS-EEG data recordings and analyses were included in the final methodological review. Specifically, three methodological categories of concurrent fNIRS-EEG data analyses, including EEG-informed fNIRS analyses, fNIRS-informed EEG analyses, and parallel fNIRS-EEG analyses, were identified and explained with detailed description. Finally, we highlighted current challenges and potential directions in concurrent fNIRS-EEG data analyses in future research

Prefrontal Activation During Inhibition of a Balance Recovery Step

The ability to quickly step is an important strategy to avoid a fall. However, real-world settings often constrain a stepping path. Such constraints necessitate response inhibition to prevent an inappropriate step and select a new course of action to ultimately recover balance. The present study investigated neural mechanisms that underlie this ability to stop a highly automatic balance recovery step. In the field of cognitive neuroscience, response inhibition has typically been researched using focal hand reaction tasks performed by seated participants. This approach combined with neuroimaging has revealed a neural stopping network, which includes the right Inferior Frontal Gyrus (right IFG) as a key node in this network. It is unclear if the same brain-based stopping networks suppress a prepotent balance reaction since compensatory balance reactions are subcortically triggered, multi-segmental responses that are much faster than voluntary reactions. To test this, functional near-infrared spectroscopy (fNIRS) was used to measure brain activity in 21 young adults (ages 18-30) as they performed a balance recovery task that demanded rapid step suppression following postural perturbation. The hypothesis was that the right IFG would show heightened activity when suppressing an automatic balance recovery step. A lean and-release system was used to impose temporally unpredictable forward perturbations by releasing participants from a supported forward lean. For most trials (80%), participants were told to recover balance by quickly stepping forward. However, on 20% of trials at random, a high-pitch tone was played immediately after postural perturbation signaling participants to suppress a step and fully relax into a catch harness. This allowed us to target the ability to cancel an already initiated step in a balance recovery context. Average Oxygenated hemoglobin (HbO2) changes were contrasted between step and stop trials, 1-6 seconds post perturbation. A two-way repeated measures ANOVA tested for main effects with condition 4 (Step, Stop), and hemisphere (right, left) and for the interaction. Post hoc analysis was performed using paired t-test comparisons between Step and Stop trials for each channel (Bonferroni correction applied). Two-way, repeated measures ANOVA showed no significant interaction (F1, 20 = 1.212, p = 0.284) between factors and no significant main effect for hemisphere (F1, 20 = 0.282, p = 0.601). However, there was a significant main effect for condition where Stop trials produced a greater response compared to Step trials (F1, 20 = 31.617, p \u3c 0.001). Follow-up analysis revealed a significant increase in three of the seven channels on each hemisphere. Consistent with the hypothesis, the results showed a greater prefrontal response during stopping trials, supporting the idea that executive brain networks are active when suppressing a balance recovery step. Contrary to our hypothesis, a similar increased response for stop trials was observed in both hemispheres indicating that step suppression was not limited to right IFG control, at least not as currently measured. This study demonstrates one way in which higher brain processes may help us prevent falls in complex environments where behavioral flexibility is necessary. This study also presents a novel method for assessing response inhibition in an upright postural context where rapid stepping reactions are required

Using Functional Near Infrared Spectroscopy to Assess Cognitive Workload

Quantification of mental workload is a significant aspect of monitoring and adaptive aiding systems that are intended to improve the efficiency and safety of human–machine systems. Functional near Infrared (fNIR) spectroscopy is a field-deployable brain monitoring device that provides a measures of cerebral hemodynamic within the prefrontal cortex. The purpose of this study was to assess the cognitive load by using Performance (reaction time), Behavioral metrics (NASA TLX) and Neuro-Cognitive Measures (Hemodynamic response). To observe the activation in prefrontal cortex, we employed Functional Near Infrared (fNIR) Spectroscopy with a Standard Stroop task. A total of 25 healthy participants (N 18 Male and N 07 Female, M Age 25.5 SD 7.6), participated in the study. For statistical analysis, a repeated measure t-test was computed to compare the Oxy (Δ[HbO2]) and De-Oxy (Δ[hHb]) changes under Congruent and In-Congruent task conditions. For Classification, Binary logistic regression model applied to identify how accurately classifying the varied workload conditions. The finding shows that fNIR measures had adequate predictive power for estimating task performance in workload conditions. In this paper, we have found evidence that fNIR can be used as indicator of cognitive load which is important for optimal human performance

Reshaping cortical activity with subthalamic stimulation in Parkinson's disease during finger tapping and gait mapped by near infrared spectroscopy

Exploration of motor cortex activity is essential to understanding the pathophysiology in Parkinson's Disease (PD), but only simple motor tasks can be investigated using a fMRI or PET. We aim to investigate the cortical activity of PD patients during a complex motor task (gait) to verify the impact of deep brain stimulation in the subthalamic nucleus (DBS-STN) by using Near-Infrared-Spectroscopy (NIRS). NIRS is a neuroimaging method of brain cortical activity using low-energy optical radiation to detect local changes in (de)oxyhemoglobin concentration. We used a multichannel portable NIRS during finger tapping (FT) and gait. To determine the signal activity, our methodology consisted of a pre-processing phase for the raw signal, followed by statistical analysis based on a general linear model. Processed recordings from 9 patients were statistically compared between the on and off states of DBS-STN. DBS-STN led to an increased activity in the contralateral motor cortex areas during FT. During gait, we observed a concentration of activity towards the cortex central area in the "stimulation-on" state. Our study shows how NIRS can be used to detect functional changes in the cortex of patients with PD with DBS-STN and indicates its future use for applications unsuited for PET and a fMRI

Neural Dynamics of Delayed Feedback in Robot Teleoperation: Insights from fNIRS Analysis

As robot teleoperation increasingly becomes integral in executing tasks in distant, hazardous, or inaccessible environments, the challenge of operational delays remains a significant obstacle. These delays are inherent in signal transmission and processing and can adversely affect the operators performance, particularly in tasks requiring precision and timeliness. While current research has made strides in mitigating these delays through advanced control strategies and training methods, a crucial gap persists in understanding the neurofunctional impacts of these delays and the efficacy of countermeasures from a cognitive perspective. Our study narrows this gap by leveraging functional Near-Infrared Spectroscopy (fNIRS) to examine the neurofunctional implications of simulated haptic feedback on cognitive activity and motor coordination under delayed conditions. In a human-subject experiment (N=41), we manipulated sensory feedback to observe its influences on various brain regions of interest (ROIs) response during teleoperation tasks. The fNIRS data provided a detailed assessment of cerebral activity, particularly in ROIs implicated in time perception and the execution of precise movements. Our results reveal that certain conditions, which provided immediate simulated haptic feedback, significantly optimized neural functions related to time perception and motor coordination, and improved motor performance. These findings provide empirical evidence about the neurofunctional basis of the enhanced motor performance with simulated synthetic force feedback in the presence of teleoperation delays.Comment: Submitted to Frontiers in Human Neuroscienc

Optical imaging and spectroscopy for the study of the human brain: status report

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit of novel methods to explore brain health and function. While the first report focused on neurophotonic tools mostly applicable to animal studies, here, we highlight optical spectroscopy and imaging methods relevant to noninvasive human brain studies. We outline current state-of-the-art technologies and software advances, explore the most recent impact of these technologies on neuroscience and clinical applications, identify the areas where innovation is needed, and provide an outlook for the future directions

Optical imaging and spectroscopy for the study of the human brain: status report.

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit of novel methods to explore brain health and function. While the first report focused on neurophotonic tools mostly applicable to animal studies, here, we highlight optical spectroscopy and imaging methods relevant to noninvasive human brain studies. We outline current state-of-the-art technologies and software advances, explore the most recent impact of these technologies on neuroscience and clinical applications, identify the areas where innovation is needed, and provide an outlook for the future directions