A 3D Look at Brainwaves: Where Does Your Alpha Power Shine?

This 3D visualization shows how EEG alpha band activity changed across the brain for one participant during the NBack working memory task, comparing brain activity in a noisy environment to a quiet control condition.

• Each colored sphere is an EEG electrode: The color reflects the percent change in alpha activity at each location, comparing the noise condition to the control.

• Red = higher alpha in noise than control

• Blue = lower alpha in noise than control

• Neutral color = no change between conditions

The transparent brain mesh gives anatomical context, helping you see where in the brain these changes occur.

What is the NBack task?

The NBack is a widely used cognitive test where participants must monitor a sequence of letters or numbers and indicate when the current item matches one presented “N” steps earlier. It’s a classic way to measure working memory and sustained attention.

Alpha waves:

Alpha waves are most prominent when we’re relaxed but alert (think: calm focus or moments before sleep). This visualization shows how environmental noise can shift the brain’s “chill zones” during a working memory challenge.

Technical note:

The color scale represents the percent change in alpha power at each electrode (noise vs control) during the NBack task. Positive values highlight sensors where alpha increased in noise; negative values show where it decreased. This approach pinpoints how environmental stressors like noise reshape brain dynamics during cognitive tasks.

For this participant, exposure to noise during the N-back task led to a notable increase in alpha power across much of the scalp, especially in posterior and lateral regions, typically a sign the brain is settling into a more relaxed or disengaged state despite the cognitive challenge. However, one striking exception emerged: a pronounced decrease in alpha power over the right centro-parietal area (CP4 - in dark blue), a region important for holding and updating information in working memory and for sustaining attention during demanding tasks like the N-back. This may reflect the brain ramping up focus in this area to compensate for the noise, even as other regions “chilled out.”

It’s interesting that this pattern somewhat aligns with the participant’s subjective experience of finding noise ‘familiar and comforting’.

Of course, with just one participant, these are simply observations, not conclusions, but they highlight the nuanced ways environmental factors can shape brain activity and experience.

This was done in my lab and is part of my research at ENRI, connecting brain health and the environment. Let me know if you’d like to see more!