Your brain's hidden filter - The "red car" effect

Have you ever noticed that once you start thinking about buying a certain car, you suddenly see it everywhere?

Psychologists sometimes call this the "red car" effect. It's not that there are more of those cars on the road – it's that your brain has decided this information is important, so you notice it.

This everyday experience gives us a window into the workings of the Reticular Activating System (RAS) – a network of neurons in the brainstem that acts as a filter, deciding which information from the outside world reaches your conscious attention.

Every second your senses bring in far more data than you could possibly process. The RAS ensures that only what seems relevant gets through.

What science tells us

Back in the 1940s, scientists discovered that when they stimulated a small network of nerves in the brainstem, people became instantly more alert. That network is what we now call the Reticular Activating System. In simple terms, it is like an on-off switch for wakefulness – deciding whether you are switched on and engaged, or drifting into sleep and distraction.

Since then, researchers have shown that the RAS does more than just keep you awake. It also acts like a filter.

Out of the millions of sights, sounds and sensations your body takes in every second, the RAS decides what deserves your attention. That is why you can sit in a noisy café and tune out the background chatter – until someone says your name.

More recent studies suggest that the RAS doesn’t work alone. It connects with other parts of the brain that handle motivation, memory and decision-making. In other words, it’s part of the system that helps you notice opportunities, remember what matters and act on it.

So while the red car effect is a metaphor, it neatly illustrates a real process: your brain is constantly filtering reality based on what you decide matters.

Why this matters for leaders

Understanding your RAS can help you use your brain’s natural filtering system to your advantage.

• Focus on what you want. If you define clear goals for yourself and your team, your RAS will start noticing opportunities and information that align with those goals. Vague or negative goals (“I don’t want to fail”) are less effective than positive, specific ones (“I want to build a confident, capable team that delivers X outcome”).

• Build confidence. The red car effect cuts both ways. If you carry self-doubt, your RAS will filter the world in ways that confirm it (“I stumbled in that meeting – I’m not a good communicator”). But if you consciously reframe your inner talk (“I’m learning and improving as a communicator”), you prime your RAS to notice progress and reinforce confidence.

• Develop competence. The RAS helps you filter the noise in complex environments. By consciously setting priorities, you train your attention to notice the right signals – whether it’s shifts in team dynamics, early signs of risk, or opportunities for innovation.

• Role-modelling presence. Because the RAS is linked to arousal and attentiveness, practices like mindfulness or intentional pausing can help leaders regulate their state. A calm, focused leader communicates competence and creates space for others to perform at their best.

Putting it into practice

1. Set clear, positive outcomes for yourself and your team.

2. Use affirming self-talk to reinforce confidence.

3. Regularly pause to check: What am I choosing to notice?

4. Align your attention with your values and strategic goals.

The Reticular Activating System is not magic. It will not achieve your goals for you. But by understanding how your brain filters attention, you can deliberately shape your focus.

For leaders, that means greater clarity, more confidence and improved focus in a world full of noise.