For decades, the frontal lobe has been the most fascinating—and most mysterious—part of the human brain. It’s the region responsible for decision-making, attention, emotional balance, planning, impulse control, and the ability to stay focused on goals. In many ways, the frontal lobe is the CEO of the brain.

Yet, until recently, understanding how this region actually functions in real time was extremely difficult. MRI scanners were too bulky and expensive, EEG was too shallow, and older imaging tools couldn’t capture the fine patterns of activity happening beneath the skull.

This is where fNIRS (Functional Near-Infrared Spectroscopy) has transformed neuroscience.

A simple, wearable, light-based technology has opened a new window into the brain’s most complex region—revealing patterns that were invisible before, and making brain research more accessible than ever.

Let’s explore how fNIRS works, why the frontal lobe matters so much, and how this technology is reshaping our understanding of human behaviour, mental health, and brain training.

Why the Frontal Lobe Is So Hard to Study

The frontal lobe is responsible for:

• controlling attention

• regulating emotions

• planning and organizing

• solving problems

• controlling impulses

• making decisions under pressure

But studying it is challenging because:

• it is hidden behind the thickest part of the skull

• its activity changes second-by-second

• it integrates emotional, cognitive, and motor information

• traditional brain scans require lying still inside large machines

In daily life, however, the frontal lobe works dynamically—during conversations, learning, stress, and problem-solving.

fNIRS finally allows us to study the frontal lobe in the real world.

How fNIRS Works (Explained Simply)

fNIRS uses harmless infrared light to measure:

• how much oxygen the frontal cortex is using

• how active different prefrontal regions are

• how the brain responds to stress, attention tasks, and emotions

When the brain works harder, it demands more oxygen-rich blood.
fNIRS picks up these changes instantly.

Think of it as a window into:

• frustration during difficult tasks

• effort while concentrating

• emotional load during stress

• fatigue when the brain gets tired

For the first time, we can see how the frontal lobe behaves moment-to-moment.

What fNIRS Has Revealed About the Frontal Lobe

1. Focus and Working Memory Are Oxygen-Hungry Processes

When you try to focus, remember something, or make a decision:

• the dorsolateral prefrontal cortex lights up

• oxygen levels increase

• effort becomes measurable

This proves that attention is a metabolic process—not just a mental one.

2. Stress Instantly Changes Frontal Activation

During anxiety, frustration, or threat:

• emotional circuits become overactive

• prefrontal regulation drops

• the brain shifts into survival mode

fNIRS shows this shift in real time, explaining why we lose clarity under stress.

3. ADHD Brains Activate Differently

Studies show:

• lower prefrontal activation during demanding tasks

• quicker mental fatigue

• compensatory “overactivation” in some children

• difficulty sustaining effort

This demonstrates that ADHD is not laziness—it is a biological difference in frontal-lobe functioning.

4. Depression Affects Motivation Circuits

fNIRS reveals that people with depression show:

• reduced activation in areas linked to drive

• slower engagement in tasks

• diminished response to reward

The frontal lobe becomes less responsive—explaining the “stuck” feeling.

5. Trauma Alters Frontal Regulation

In trauma and PTSD:

• emotional regions overpower the frontal cortex

• stress shuts down rational processing

• the brain struggles to return to calm

This explains emotional numbness, reactivity, and difficulty with concentration.

6. Fatigue and Burnout Show Up in the Frontal Lobe

With chronic stress, fNIRS shows:

• delayed activation

• reduced oxygenation

• poor recovery from cognitive effort

This offers a biological explanation for burnout and mental exhaustion.

The Gamechanger: Bringing fNIRS Insights Home

Until recently, fNIRS equipment was limited to:

• university labs

• neuroscience research centres

• specialised clinics

Now, wearable devices like the Muse S Athena allow clinicians to apply fNIRS-informed brain training at home.

This means:

• people can strengthen frontal-lobe activation

• children with ADHD can train executive circuits

• adults can improve focus and emotional resilience

• individuals can track stress and recovery

• sleep and cognition can be monitored

• neurofeedback protocols can be personalised

The mysteries of the frontal lobe are no longer locked inside research labs.
They are finally accessible—helping people understand, train, and optimize their brain in daily life.

The Bottom Line

fNIRS has transformed how we understand the frontal lobe.
It shows us how attention, emotions, stress, and decision-making unfold in real time.
And with modern wearable tools, this technology is no longer only for scientists—it’s becoming part of everyday mental health care.

We are entering a new era:
One where the brain’s most complex region is no longer a mystery, but a map we can read, understand, and train.

For ADHD Brain Mapping, fNIRS-Informed Neurofeedback & Prefrontal Training

Dr. Srinivas Rajkumar T, MD (AIIMS), DNB, MBA (BITS Pilani)
Consultant Psychiatrist & Neurofeedback Specialist
Mind & Memory Clinic, Apollo Clinic Velachery (Opp. Phoenix Mall)
✉ srinivasaiims@gmail.com 📞 +91-8595155808