Near-infrared spectroscopy (NIRS):
Near-infrared spectroscopy (NIRS) is a fascinating technique that uses light to measure blood flow and oxygenation in the brain. Unlike its MRI counterpart, it offers a unique blend of portability, affordability, and real-time information, making it valuable in various research and clinical settings.
How does it work?
NIRS utilizes near-infrared light, which readily penetrates tissue without causing harm. This light is emitted by probes placed on the scalp and interacts with oxygenated and deoxygenated hemoglobin in the blood. By analyzing the reflected light patterns, NIRS can estimate the relative changes in blood oxygenation levels in specific brain regions.
Advantages of NIRS:
- Non-invasive and safe:
No radiation exposure or injections are involved, making it suitable for even infants and newborns.
- Portable and flexible:
NIRS equipment is relatively compact and allows for movement, unlike the large machines needed for fMRI.
- Real-time monitoring:
NIRS provides continuous updates on blood oxygenation changes, offering valuable insights into dynamic brain activity.
- Cost-effective:
Compared to fMRI, NIRS equipment and procedures are less expensive, making it more accessible.
Applications of NIRS:
- Brain research:
Studying brain function during various cognitive tasks, emotional responses, and neurodevelopmental processes.
- Clinical monitoring:
Assessing brain health in critically ill patients, monitoring for strokes or seizures, and evaluating neurological disorders.
- Sports medicine:
Studying the impact of exercise and training on brain function in athletes.
- Ergonomics and rehabilitation:
Optimizing training protocols and monitoring recovery progress in neurological patients.
Limitations of NIRS:
- Limited depth penetration:
NIRS signals mainly reach the surface layers of the brain, making it less suitable for studying deeper structures.
- Susceptibility to interference:
Hair, skull thickness, and blood vessel variations can influence the signal and require careful consideration.
- Indirect measure:
Similar to fMRI, NIRS measures blood flow changes, not directly the electrical activity of neurons.
Overall, NIRS stands as a powerful and versatile tool for understanding brain function in real-time, offering valuable insights into both healthy and diseased states. With ongoing research and technological advancements, its potential applications are likely to expand further in the future.
