by Sabrina Sghirripa
Have you ever been counting something, and someone starts yelling out random numbers while you’re trying to stay focused? Did you feel as if the fact they were calling out numbers made it 100x harder to count?
If so, congratulations, you have a fully functioning central nervous system! Being able to block out things that aren’t relevant to our goals is an essential component of learning, memory and attention. Our brains are constantly filtering out what we don’t need to take notice of, and what we really should be.
So, while that idiot is yelling out numbers to put you off, at the neural level, there exists a range of mechanisms that might allow us to suppress distractors.
One player in the game are brain waves (or neural oscillations). Our brains are constantly engaging in rhythmic activity- the billions of brain cells (neurons) in the cortex are communicating with each other, producing electricity that can be measured from the scalp using electroencephalography (EEG). These rhythms are thought to be involved in many aspects of human behaviour.
One type oscillation are alpha waves, which are thought to play an inhibitory role in the brain. Imagine there’s a party going between some cells in a brain region. When the alpha waves arrive, everything quiets down. This party-pooper property is not necessarily a bad thing, as this is why alpha waves have been linked to the ability for us to block out distracting information.
Back to the numbers example, when you’re trying to count (which is processed using the frontal parts of your brain) and someone is yelling numbers (which is processed in the sound areas of the brain), alpha activity increases in the area where sound is processed- essentially telling the sound centre to stop worrying about the noise. Therefore, you pay less attention to the annoying person, helping you to focus on the task rather than the distracting sounds. Mind you, it is much harder to suppress distracting information when the distractor is the same sort of information as the thing you’re trying to focus on. In other words, numbers are more distracting when you’re trying to count, just as letters are more distracting when you’re trying to spell.
However, the above example relates to a level that we are consciously aware of. While we can control our focus when it comes to something like counting or solving a puzzle, our brains are receiving so much information all the time. For example, we can’t feel our clothes on our skin unless we direct attention towards it- highlighting how we cannot pay attention to or even notice half of the sensory information we are experiencing.
That’s all good and well, but why should we care about this?
You may not realise it, but this ability to selectively attend to stimuli is critical for the activities of everyday life. Our memory systems couldn’t function without the ability for goal-directed thought. As such, the inability to filter out distracting information (and other memory issues) are linked with cognitive ageing and diseases such as Alzheimer’s and schizophrenia. Therefore, it is important for neuroscientists to understand how and where things go wrong during cognitive processes in order for us to make progress in preventing and identifying disease.
Despite all this, brain waves are only part of the story when it comes to working out how humans think and behave, as well as trying to work out why diseases can cause this to go wrong. The brains studying brains are constantly discovering new biological mechanisms that help us to explain the processes that give humans their intelligence and complexity.
Why not test your own ability to deal with different distractors? Try and do your homework while listening to music, snapchatting your mates and watching Netflix. I think I know what the outcome will be. I’d hate to be like a nagging parent, but even neuroscience isn’t on your side with this one!