Brain Training: Why It Works for Some, But Not Others

You might think that training your brain is like lifting weights: if you put in the effort, the muscle grows. It is a seductive idea. However, when scientists test brain training methods in the lab, the results are often messy and inconsistent. Why does a therapy work wonders for one person and completely fail for another? A new study on the ageing brain offers a clear answer: we have been looking at the averages, when we should have been looking at the individuals.

The Fading Signal

Deep inside your skull, neurons communicate using electrical pulses. When you are concentrating hard or recalling a memory, these pulses sync up in a fast rhythm known as ‘Gamma-band synchronisation’. You can think of this as the brain’s internal clock speed. It keeps cognitive functions sharp.

Here is the problem: as we age, this Gamma rhythm tends to fade. The signal gets weaker. To fix this, researchers use EEG-Neurofeedback. This technology connects your brainwaves to a computer screen. If you successfully increase your Gamma waves, the computer gives you positive feedback—perhaps a bar on the screen goes up. The goal is to teach your brain to self-regulate and restore that lost rhythm.

The Hidden Split

In this double-blind trial, researchers tested this method on older adults who were worried about their memory. They used advanced machine learning to analyse the results, rather than just looking at a simple group average. This is where they found the missing piece of the puzzle.

The participants in the real training group actually split into two distinct camps. One subgroup was highly successful; they managed to ramp up their Gamma synchronisation significantly. Their brains learned the lesson. The other subgroup, despite receiving the exact same training, showed neural responses identical to the ‘sham’ group who received fake feedback. The training simply did not take hold.

Moving Beyond Averages

This explains why previous studies on neurofeedback have been so heterogeneous. If you average the ‘responders’ with the ‘non-responders’, the therapy looks mediocre. But when you separate them, you see that for the right person, this is a powerful tool.

The study suggests that successful brain training is not just about the method; it is about the individual neural dynamics of the person sitting in the chair. We are moving away from a ‘one size fits all’ model towards a bespoke approach to healthy brain ageing. The question is no longer just “does it work?”, but “who does it work for?”