fNIRS Archives - BIOPAC Blog

2025: The Year in Review

As 2025 winds to a close, there is much to celebrate both here at BIOPAC and in the ever-expanding frontiers of research that our products engage with every day. Let’s take a quick look at where we have been over the past 12 months and what the future holds.

Popular Posts

Speaking of engagement, this is the time of year when we do a bit of self-assessment and revisit what topics our readers were most inspired by and most interested in. Apparently, many of our readers are closet gamers at heart, because our blog on research on game design and gaming impacts drove more eyes to our site than any other topic this year, followed by posts on cognitive neuroscience and aging and the human impact of isolation.

New Products and Updates

On the heels of the 2024 release of our flagship MP200 data acquisition and analysis system and a significant upgrade to AcqKnowledge software, 2025 concludes with another milestone: the imminent release of AcqKnowledge 6.0.2. This latest version features a host of improvements and additions, including full integration of MedelOpt+, which blends whole-head functional near-infrared spectroscopy (fNIRS) with electroencephalography (EEG) in a single, highly flexible device.

BIOPAC in the Lab

Every year, BIOPAC products continue to drive the most exciting research in physiology, psychology, and neurology, and 2025 was no different. Each month, we highlight breakthrough studies in which BIOPAC played a role in gathering and analyzing key data. These are usually centered around a theme and feature research published in the last few years. To close out the year, we like to spotlight a couple of significant studies from 2025 that didn’t get mentioned.

A collaborative study by researchers from the University of Georgia and Beijing Normal University examined how mothers and children coordinate their physiological responses during stressful interactions. Using BIOPAC data acquisition systems coupled with wireless ECG transmitters, the team simultaneously recorded cardiac activity from each participant pair as they completed structured challenge tasks. This setup provided the temporal precision needed to track changes in heart rate and moment-to-moment autonomic synchrony, revealing how caregivers and children influence one another biologically during shared stress. The study found that greater synchrony was linked to both emotional dynamics and regulatory behaviors during the tasks, highlighting the deep coupling between social relationships and physiological responses. The wireless BIOPAC configuration enabled naturalistic interaction while capturing high-quality dyadic data, a persistent challenge in synchrony research.

In its first full year of availability, the MP200 is already making waves in the research community. At Guangdong University of Science and Technology in China, researchers examined how head-shoulder posture and cervical muscle activation differ between college students with chronic neck pain (CNP) and healthy individuals. The team employed surface electromyography (sEMG) recorded with a BIOPAC MP200 data acquisition system and AcqKnowledge software. Researchers placed surface electrodes over targeted neck muscles to record raw EMG signals during various strength tests and physical tasks. Students with CNP demonstrated significantly poorer head and shoulder alignment, reduced neck extensor strength, and altered EMG activity, indicating neuromuscular dysfunction associated with pain. Findings showed the connection between altered posture and impaired muscle function in chronic neck pain. The study demonstrates the effectiveness of surface EMG to support clinical diagnosis and rehabilitation.

For more inspiration as we head into 2026, explore our webinar library for tips, tricks, and methods directly from experts across a range of research fields.

If you are planning to launch a study for 2026, now is the time to reach out to your nearest BIOPAC customer service representative for help finding the right tools to get started.

Brain and Body: SPA-fNIRS Solves Physiological Signal Noise

Functional near-infrared spectroscopy (fNIRS) offers researchers a powerful noninvasive tool for studying brain activity by measuring changes in blood oxygen levels. These changes reflect how various brain regions respond to stimuli such as tasks that involve thinking, emotion, movement, and social interaction. These are often in natural, real-world settings that are not possible with other brain imaging methods. However, fNIRS is not without its own limitations. Systemic fluctuations in the body, such as breathing patterns, cardiovascular changes, and autonomic responses, can result in signal noise that is misinterpreted as brain activity by traditional fNIRS. The solution: a visit to the SPA.

Systemic Physiology Augmented fNIRS (SPA-fNIRS) is an advanced approach to fNIRS that goes beyond measuring local changes in cerebral oxygenation. While standard fNIRS measures cortical hemodynamics by tracking oxygenated (HbO) and deoxygenated (HbR) hemoglobin, noise originating from systemic physiological changes can corrupt those signals. Combining data from both neural and systemic physiological signals, SPA-fNIRS provides researchers with a more diverse and accurate view of how the brain and body interact in real time.

The method is being applied across various fields, including psychophysiology, cognitive neuroscience, exercise physiology, mental health, and human performance research. Studies have utilized SPA-fNIRS to investigate a range of topics, including meditation and emotional regulation, movement control, and social interaction. The broader goal is to move beyond studying the brain in isolation and to understand it as part of an integrated mind-body system. This holistic view is transforming how scientists interpret brain-function data, opening new paths for applied research in education, rehabilitation, and human-machine interface design.

Researchers in India investigated the impact of a traditional sound-based meditation technique, known as the Mind-Sound Resonance Technique (MSRT), on both brain and heart activity. Using fNIRS to track changes in oxygen levels in the prefrontal cortex, and a BIOPAC data acquisition and analysis system with AcqKnowledge software to record and analyze heart rate variability (HRV), the study employed a SPA-fNIRS design, integrating neural and physiological data in a single, synchronized dataset. HRV analysis allowed the researchers to quantify shifts in autonomic balance during and after meditation. The results showed increased oxygenation in the right prefrontal cortex and enhanced low-frequency HRV components, reflecting greater parasympathetic regulation. Together, these findings suggest that sound-based meditation not only improves brain oxygenation but also promotes calmer, more balanced heart-brain dynamics, illustrating how SPA-fNIRS methods can reveal the comprehensive physiological impact of mindfulness practices.

In her doctoral research at the Université de Lille in France, neuroscientist Aurore Guérin examined how the brain controls movement speed using a multimodal combination of fNIRS and physiological data recording systems. Participants performed repetitive arm movements at fast, natural, and slow tempos. At the same time, the study captured oxygenation in the prefrontal and motor cortices using fNIRS, alongside heart rate and respiration signals collected with a BIOPAC data acquisition system. A respiratory effort transducer measured breathing patterns, while a BioNomadix ECG module recorded cardiac activity for HRV analysis. All physiological signals were synchronized and analyzed in AcqKnowledge software, allowing the team to identify and remove systemic influences (e.g., heartbeat and breathing rhythms) from the fNIRS signals, following a SPA-fNIRS approach. The results revealed that faster movements primarily engaged motor regions, while slower, more deliberate pacing resulted in higher prefrontal activation, reflecting greater cognitive control. By integrating physiological monitoring with fNIRS, the study provided a clearer picture of how the brain and body coordinate timing and control during movement.

These studies illustrate how SPA-fNIRS is reshaping the way scientists investigate the interaction between brain and body. By combining neural and physiological data in a single synchronized system, researchers can separate brain activity from systemic noise and uncover the interplay between cognition, emotion, and autonomic regulation. For more information on this topic, watch our webinar on Multimodal SPA-fNIRS and check our our latest multimoldal fNIRS research products.

Are you planning a study that blends fNIRS with other physiological signals? Contact your local BIOPAC customer service representative to learn more about how SPA-fNIRS can benefit your research.

Aesthetically Pleasing: Exploring How the Brain Perceives the Arts

Beauty is in the eye of the beholder—a mostly subjective experience, so the saying implies. While we may share many common ideals about beauty and aesthetics, our reactions to art, music, and literature can diverge, converge, and overlap to a myriad of degrees. Neuroaesthetics explores how the brain perceives and responds to art, music, and other aesthetically evocative experiences. Combining neuroscience with psychology and the arts, researchers seek to understand why humans find certain images, sounds, or designs appealing and how these perceptions influence our emotions, cognition, and behavior. This interdisciplinary science has practical applications across a wide range of fields, including design, marketing, education, and mental health therapy, where understanding aesthetic experience can inform and enhance user engagement, learning, and emotional well-being.

Biometric signals provide insight into emotional and cognitive processing, allowing researchers to gain valuable data on how the brain creates and responds to aesthetically engaging stimuli. Commonly used techniques include electrodermal activity (EDA), which measures changes in skin conductance linked to emotional arousal; electroencephalography (EEG), which tracks brainwave patterns associated with attention and engagement; functional near-infrared spectroscopy (fNIRS), which monitors blood flow changes in the brain; and functional magnetic resonance imaging (fMRI), which provides high-resolution images of neural activity.

Additionally, the use of virtual reality (VR) and augmented reality (AR) is expanding in neuroaesthetics research, allowing scientists to create controlled, immersive environments that mimic real-world experiences. These technologies offer new ways to investigate how individuals engage with art and design in dynamic, interactive settings, pushing the boundaries of how we understand and harness aesthetic experiences.

Researchers in Shanghai, China, for example, investigated how different visual modes—2D and 3D VR—affect emotional arousal, demonstrating how immersive environments influence emotional experiences. The research team utilized EEG to monitor brain activity and EDA to measure skin conductance responses, both indicators of emotional arousal. EDA and EEG data were recorded while study participants wore VR headsets to view 2D and 3D environments. Data was collected and analyzed using a BIOPAC MP system with AcqKnowledge software. The findings revealed that 3D VR environments elicited more intense emotional stimulation than 2D settings, as evidenced by higher beta (21–30 Hz) EEG power and increased EDA responses. According to the published findings, results suggest that enhanced perception in 3D environments leads to greater emotional engagement, highlighting the potential of 3D VR in applications such as immersive therapy, virtual training, and interactive entertainment.

A team of German researchers recently examined the intersection of neurology, psychology, music, and literature. Their findings, published in the journal NeuroImage, explored how melodic features influence the neural processing of spoken poems and songs, examining the interplay between language and music. Researchers employed fMRI to investigate the neural mechanisms underlying the processing of musical and nonmusical verse. The fMRI data revealed that both spoken poems and songs activated bilateral temporal auditory areas of the brain. One aspect of the study was the measurement of participants’ emotional responses to the stimulus, i.e., whether they liked the song or poem to which they were listening while the fMRI scan was conducted. To gather this data, participants interacted with a BIOPAC differential pressure transducer connected to the participants’ right and left index fingers to record the degree to which they enjoyed the music. The researchers stated the findings suggest that melodic properties are central to the aesthetic experience of both speech and music.

A study published by Britain’s Royal Society looked at the connection between aesthetic appreciation and emotional states, specifically how exposure to art or music can shift feelings of anxiety to curiosity. To understand how the brain perceives beauty, the researchers used EDA to assess participants’ physiological arousal during exposure to aesthetically pleasing stimuli, such as music. EDA data was gathered using a BIOPAC EDA amplifier connected to a data acquisition and analysis system while participants were administered anxiety-inducing electrical tactile stimulation during music listening sessions. The study demonstrated that aesthetic appreciation can reduce anxiety and promote curiosity by analyzing the EDA data alongside self-reported measures. The research team concluded that their results “might have potential applications across different human activities such as learning and therapy. The idea that aesthetic appreciation might affect anxious states and that expecting aesthetic rewards can transform anxiety into arousal and curiosity plays a central role in some psychotherapeutic models of human change.”

These examples provide a rough outline of a bigger picture, illustrating the many ways researchers use physiological signals to better understand the human mind’s response to art, music, and literature. For more information on the tools BIOPAC provides to assist in neurological and physiological research, see our online training and webinars.

Are you planning a research project to investigate the intersection of aesthetics and neuroscience? Contact a BIOPAC representative in your area to identify the right resources and equipment for a successful study.

Mind and Machine: Exploring Brain-Computer Interfaces

In neuroscience, the frontier of brain-computer interfaces (BCI) holds the promise of bridging the gap between the human brain and external devices, offering revolutionary applications in fields ranging from robotics and prosthetics to communication and beyond. In the lab, scientists studying and developing new BCI technology leverage the human brain’s electrical and physiological signals.

Electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and steady-state visually evoked potentials (SSVEP) are among the primary physiological and psychophysiological signals utilized in these investigations. Multimodal integration of two or more signal types allows researchers and engineers to take advantage of multiple data streams in their applications and studies.

EEG, which can measure electrical activity in the brain, is a cornerstone of BCI research. Researchers can decode various mental states and intentions by analyzing EEG patterns, enabling users to control external devices through mere thought. fNIRS complements EEG by measuring changes in blood oxygenation levels, offering insights into brain function with superior spatial resolution. SSVEP, on the other hand, capitalizes on the brain’s response to visual stimuli, providing a means for precise control in BCI applications.

The practical implications of BCI research extend far beyond the laboratory setting. In robotics, BCIs facilitate direct brain-to-machine communication, empowering users to manipulate robotic arms or navigate autonomous vehicles with their thoughts alone. A study published in the Journal of Information Science Engineering explored ways that an SSVEP-based BCI could be used to control assembly line robots via a headset measuring the operator’s EEG signals. The signals would communicate instructions to robots while operators identified defective parts, which the robots would pick out. During the experiment, EEG signals were obtained using a B-Alert X24 headset. The EEG-based BCI produced a 93.33% success rate in correctly identifying and removing defective parts from the assembly line process, allowing the operator to effectively “collaborate with the robot and communicate defective parts without manually operating the robot.”

Prosthetics benefit immensely from BCI advancements, enabling seamless integration with the user’s neural signals for intuitive control and enhanced functionality. A 2023 study by a team of researchers from the University of California Irvine explored the viability of creating low-cost cortical stimulators for bi-directional BCI (BD-BCI) research. BD-BCI takes brain-computer-interfaces to the next level with the brain not only providing motor commands to an artificial limb but also allowing it to receive sensory input from such a device. A BIOPAC data acquisition and analysis system was used to validate the charge balancing of subcortical electrocorticographic (ECoG) implants used in a stimulator. The charge balancing test was performed on phantom tissue designed to simulate real brain tissue. The resulting study successfully demonstrated “clinical validation of a fully-programmable electrical stimulator, integrated into an embedded BCI system.”

As researchers continue to refine BCI technologies, the possibilities for real-world applications are boundless. BIOPAC is among the companies on the cutting edge of BCI research, partnering with other innovators to provide the latest in multimodal BCI technologies such as Axon-R. For additional information on Axon-R, check out our recent webinar on the device.

Are you planning to explore the frontiers of BCI in the lab? Our regional customer reps have all the knowledge you need to integrate BIOPAC products into your BCI study.

VR Integration: Enhancing Research with Virtual Environments

Measuring the human body and brain’s response to real-world conditions and stimuli has long challenged researchers. This problem has usually been dealt with in one of two ways. The first approach is to take research participants into the field—not impossible with today’s mobile data recording technology but not always safe or convenient. The second option is to imitate real-world conditions in the lab using screens, audio equipment, and even scent delivery, but in the end, it is difficult to completely remove the lab setting from the participant’s experience—that is, until the introduction of Virtual Reality (VR) technology in research.

Just as it has revolutionized everything from entertainment to training, VR has provided researchers with the opportunity to create immersive experiences in the lab that mimic the real world. Advances in technology have not only made these simulated environments more realistic, but they have also made it easier to integrate a wide range of signals and stimulus delivery to enhance the recording of physiological and psychophysiological data.

BIOPAC, through cooperation with several partner companies, offers a range of data recording options that integrate seamlessly with third-party VR devices. fNIR Devices, for example, designs solutions for recording functional near-infrared spectroscopy (fNIRS) signals that can easily be incorporated with standard VR head-mounted displays (HMD) to measure neural activity and hemodynamic response in the prefrontal cortex while participants experience VR environments. BIOPAC partner Seenel has created MedelOpt, a line of whole-head wearable devices that combine electroencephalography (EEG) and fNIRS, including a VR option that integrates an HMD. Finally, partner company WorldViz offers a full spectrum of VR solutions from complete VR kits to full-room Projection VR technology to software that can be combined with both wired and wireless data recording technologies to provide a complete array of bio-signal data, from eye tracking to electrodermal activity.

A Canadian study published in 2023 used a combination of BIOPAC and WorldViz products to investigate how sensory feedback and arousal influence neuromus cular control and posture. Researchers measured arousal via electrodermal activity (EDA) and psychosocial questionnaires, rating perceived fear and anxiety in both real-world situations in VR environments that simulated standing both at ground level and on a raised platform. Participants wore a commercial HMD running WorldViz’s Vizard VR toolkit software. Electrical nerve stimulation was provided via a BIOPAC linear isolated stimulator. The study found the “physiological and perceptual indicators of fear and anxiety increased” in the VR platform simulation, providing “novel evidence that VR can be used to modulate upright postural control.”

A similar study published in the 2022 issue of the Journal of Sport Rehabilitation examined the effect non-physical mental training has on balance skills. The study used fNIRS technology to measure hemodynamic response in the prefrontal cortex of participants experiencing virtual environments through VR HMDs. Participants were instructed to imagine themselves imitating balance exercises viewed through an Oculus VR HMD while also fitted with an fNIR Devices Imager headband. Data was gathered using Cobi Studio software and analyzed via fNIRSoft software. The study identified several advantages of virtual reality mental training (VRMT) over conventional mental training (CMT).

These are just a few examples of how VR technology can be integrated with a variety of methodologies for gathering research data. For additional information on the subject, check out our Virtual Reality Resources, which include an array of online training on integrating VR into research.

Are you planning a research product and need help integrating VR with other data acquisition and analysis equipment? Contact your local BIOPAC sales rep to find the right solutions for you.

fNIRS and the Brain: How cognition is defined and recorded

As the most crucial organ of the human body that quintessentially defines humanity, the brain is still our greatest puzzle to solve. Medical doctors, neuroscientists, physiological scientists, and others have been trying to understand how its functions affect our actions, dating all the way back to the dark days of phrenology. In our study of the brain, the popular research is directed towards conscious thought, thinking, or the scientific term, cognition. In physical terms, the brain is separated into different areas of grey matter for different tasks, and like an electricity operator supplies a power grid with different levels of electricity on demand, regions of the brain gearing up for critical thought are saturated with fresh, oxygenated blood to boost performance: again a sign of an active cognitive state.

In modern scientific research, one of the popular means to measure this oxygenation is through Spectroscopy—more specifically, a unique field called functional near infrared spectroscopy. How does fNIRS work in measuring human cognition? These measurements are performed with optical diodes and sensors measuring a near infrared wave pattern.

Dedicated fNIRS software displaying tissue oxygenation — A graphical display of oxygenation in the prefrontal cortex

Near infrared light is sent through the skull in a spectrum that can pass through bone and tissue, and the sensors record the plots of photons absorbed by tissue or reflected back. Naturally with such a delicate subject such as the human brain, this process is both safe for the participant and painless.

The practical benefits of this spectroscopic measurement are numerous—continuous and real time values on changes in hemoglobin levels in the prefrontal cortex (measured as oxyhemoglobin [Hb] and deoxygenated hemoglobin [HbO₂]) as subjects perform different tasks, either in a stationary recording position or in a mobile experiment environment. fNIRS technology offers standalone and field-deployable technology able to determine localized brain activity. Modern recording tools such as the fNIR103M offer a wireless recording platform, so research subjects can react naturally in real-world situations outside of the lab environment while continuously recording spectroscopic data.

fNIRS is a popular signal to record simultaneously with other physiological signals such as heart rate, ECG, HRV, EMG, respiration, and more to get a clear picture of a subject’s physiological reactions. Application areas for this signal typically include pain assessment, geriatrics, attention, sports science, Human-Computer Interface, virtual reality, stress, workload assessment, and learning. Thousands of scholarly citations have been written featuring functional near-infrared spectroscopy, as studies visualize how the brain works through cognitive problems and processes. To further your physiological research, BIOPAC’s AcqKnowledge software can record multiple physiological signals at once and provide automated analysis tools for event related potentials and ensemble averaging. fNIRS easily integrates with other physiological and neurobehavioral methods of assessing brain activity, including eye tracking, pupil reflex, respiration, and electrodermal activity.

BIOPAC Systems, Inc. provides life science researchers and educators with data acquisition and analysis systems that inspire people and enable greater discovery about life. Visit us at www.biopac.com. We invite you to look at our fNIRS webinars from BIOPAC. BIOPAC also offers a line of wired and wireless fNIRS imagers for research and education.