Sporting success from faster eye frame rates

The ability to react quickly is a crucial part of most organisms' lives. In the natural world, a split second can make the difference between living and dying. Us humans have it a bit easier than that, but it’s undeniable that fast perceptions can be hugely advantageous in fields such as professional sports, or on the battlefield. And now scientists at Trinity College Dublin might have an answer as to why some people can react quicker than others. It turns out that every individuals’ eyes have a different ‘temporal resolution’, that is to say some people literally see more frames per second than others. And if your eyes have a finer frame rate, your brain can see and react to things faster. Will Tingle has been speaking to Kevin Mitchell and, before him, Clinton Haarlem.

Clinton - We took a little light bulb that could flicker at different frequencies and when you flicker at really, really high rates, then there's a certain point where you can't actually see the flicker anymore and the light just looks still, but the exact frequency where that happens is different for different people. So we just made a whole bunch of people look at this light and recorded the exact point where they stopped seeing the flicker.

Will - So how much variation was there across all the people that you measured?

Clinton - Yeah, it varied quite a bit. So we measured this in Hertz, so in flashes per second, and on the lower end of the spectrum, people saw about 30 flashes per second. But people on the higher end saw more than 60.

Will - To bring you in. Kevin, could you talk us through why that might be happening?

Kevin - Any kind of trait that is typical of a species will also vary within the species. So if you think of height for example, humans are about yea high on average, but there's lots of variation around that. And what's really interesting is that a lot of that variation we're generally kind of unaware of, especially when it comes to perception because it's such a subjective sort of experience. And we may not realise that we are seeing the world literally differently than other people do.

Will - Does this access to higher frame rates in certain individuals allow them to do things that perhaps others might not be capable of?

Kevin - My gut feeling is that actually most of the time the variation that we've seen probably won't affect people in most of their daily lives, except maybe some people will see some things flickering and it might bother them. But where we do think it might come into play is in things like high speed sports where the need to be able to track very fast moving objects, for example, might make the difference between being a top tier baseball player or a cricketer or hurler as opposed to not.

Will - So this is the reason why I was so bad at sports at school, do you think?

Kevin - Exactly you can blame your slow eyes, Will.

Will - Clinton to bring you back in? We've spoken so far about the potential advantages of having a high frame rate, high temporal resolution. Do we think there's any use to having a low one?

Clinton - Well, I don't exactly know if that would be the case in humans, but what we see from the animal kingdom is that nocturnal animals tend to have really low temporal resolution and that's really so that their visual system has more time to collect these light particles and and make up an image for them to see. And the other thing might also be that animals that need to be aware of very slowly moving things in their environment, they might need that longer integration time. So for example, if you think about a flower blooming and we look at that, we don't actually see that happening because it's so slow and takes so long for that movement to happen. But if you were to take a snapshot once per hour, then you definitely see that movement and that's something that animals might be able to do

Will - In nature, we see the highest frame rate of any animal that we know to date is the peregrine falcon. That's a predator. Our ancestors were predators as well. If a higher frame rate makes you a better predator, why do we think then that there is a limit?

Kevin -I think part of the answer to that is actually that there's a cost to it. So if we're collecting all that information, we have to capture it, we have to transmit it within the brain, we have to process it. All of that has a lot of energetic cost. So for organisms who are in a niche where they don't need to do that then they won't have those high frame rates just because the cost is too high. And Clinton has found differences between predators that are active predators like a peregrine falcon versus ones that are ambush predators that just sit and wait. And the ambush ones have much lower frame rates basically because they don't need to be tracking the fast moving things. They just wait for something to come along.

Will - Fascinating, isn't it? Everything is a trade off in evolutionary terms. Where next then for this fascinating piece of study?

Kevin - We're sort of speculating about the idea that this temporal resolution will map onto motion tracking ability. And there's some good reason to think that based on animal studies and other human studies, but we really have to explore that in much more detail and also see whether, you know, speed of perception is matched by speed of action. Whether people's reflexes are also faster. If they can see the world faster, maybe they can act on it faster. We don't know if those things are coupled in individuals or if they vary independently. So there's a whole host of questions that this study opens up.

Will - That'd be remarkable, wouldn't it? If after all this time the source of most people's clumsiness is the fact that their frame rate doesn't match their ability to react.

Kevin - Absolutely. Yeah.