How adverts could attract your attention
Chris - Now, we're talking about advertising and one of the main aims of an advert or a billboard, or a poster is of course to attract your attention. So, how does the brain actually decide what it's going to look at? To help us decide and work out what makes things eye-catching is Dr. Andy Parton who's a lecturer in psychology at Brunel University. Hello, Andy.
Andy - Hi, Chris.
Chris - So tell us, if I want to make the advert from heaven that's going to guarantee me some sales, what do we need to know about how the brain works? How would you do that?
Andy - Well it's a very complex question. I guess what we're looking at from our point of view is mechanisms underlying the processes of what we call "visual attention." So, if you imagine when you look around a complex scene, there are many things that you could actually look at and choose to look at, or just without thinking, look at. And the way that that is determined is by the process of attention. Some of the things are really kind of obvious. So, if for example, most of the things in the room are black and then suddenly something very bright, you will tend to look over at it, so things that stand out and are quite obvious you'll look at. But there are other things which are - maybe to do with strategy, what are you interested in. So, if I'm searching around in my living room, trying to find my keys, then I'm probably going to spend time attending to things that are a bit shiny and a bit metallic as opposed to things that are clearly not my keys.
Chris - Indeed, but the point is that if you're looking for those keys, the brain is being assailed by this barrage of sensory information which is going to include things that aren't keys, things that are keys. How does the brain assign to the sensory information that's coming in, some kind of label to say, "Hey, that's important. That's what I've got to look for."?
Andy - Again, that's a very tricky thing and it is dependent on both the basic visual properties and the strategic aims of the person looking around. What we were interested in doing is I guess at one level above that and actually looking at the actual code that the brain uses for achieving this. So, assuming that you want to attend to a sort of one thing, how do you actually code that differently so it kind of stands out amongst the coding within the brain?
Chris - Indeed. So what did you do to try and understand that?
Andy - Well, we looked at the theory which suggests that actually to do this, the brain needs to recruit lots of areas across the brain simultaneously and it needs to link all of their activity. It does this by briefly synchronising the firings of nerve cells and neurons in those parts of the brain at the same time. To actually try and induce that experimentally, to actually get the brain to do that without specifically changing attention, we found another study which had suggested that basically, if you look at a light that flickers, your neurons in your brain actually change their activity at the same rates as the flickering light. Even when the light is flickering at such a fast speed that you can't actually tell it's flickering. So it's entirely subliminal to you that this light is flickering, but the neurons in your brain - you can measure them with an EEG - are actually changing their activity at the same speed.
Chris - So what are you saying? That there's some kind of magic flicker rate which if things are pulsing on and off at just that sweet level, the brain will pay more attention to that because it makes these different bits of the brain all fire off, all the ducks are lined up in a row and they all go down together sort of thing.
Andy - Yes. I mean, that was the basic idea. It was not that the brain is designed when things are flickering before us to do that, but because the brain uses neurons, changing at that speed for its code, if you can actually induce that, it will have the effect of directing attention.
Chris - So how did you do it?
Andy - Well, we had a computer screen and we had three small patches on it and a fixation cross in the centre. So people look at the fixation cross and they attend to the three patches, and they're told that these stripy patches, one of them will have a brief change in the width of the stripes and they have to indicate which of the three it is. What they don't know is that before that occurs for a second, one of the patches is flickering at our critical speed. We know they don't know this because we did a separate study in which they had the patches and they had to detect if there was any difference between them, and they couldn't spot whether one was flickering or not above chance; they were entirely random. So people can't detect this, but what we found was when we did this flicker manipulation, if the change in the width of the patch occurred at the same location that has been flickering, even though people couldn't see it, they were much faster at indicating there was a change there. And if it was at another location, one of the other two patches, they were much slower at indicating that the change was there.
Chris - Because their attention was being drawn to the one that was flickering and drawn away from the one that wasn't, so they were missing the one that was changing in the patch that wasn't flickering, but they were attending much better to the patch that was flickering and that's why they saw it better.
Andy - Absolutely. That's exactly it and we did another similar thing where they have to actually - a much more subtle change and it's much more difficult to detect and we showed that again, if there was a flicker there before people could detect, there's change, but if there wasn't, they were very unlikely to change it or to detect it.
Chris - And so the logical extension of this would be then, you found that there seems to be this coding, written into how the brain pays attention to things. Could advertisers exploit that in order to make TV adverts that are more arresting than other content or to make billboards that are more arresting so you pay attention to them and pay attention to the message for longer than you otherwise would?
Andy - I think it's certainly - there are a couple of problems, but certainly in principle, possible that if you have a kind of crowded scene, you could draw people to attend to that in comparison to other things that are around. Particularly one might think that if you're looking on an internet screen and you go to a web page, people are actually fairly skilled at avoiding looking at adverts when they go into web pages.
Chris - I'm one of them.
Andy - Yes, absolutely me too, but if you can have something that would just draw them, and bias them to look at it briefly, that might obviously increase the effectiveness of that advert. The one problem is of course, you'll never know what screen people are looking at the adverts on and so it's very difficult to know precisely what speed the flicker will be at because screens run at different speeds. And so, some people will see it at one speed and some people will see it in another. I mean, I guess you can go for the most common kind of screen speed, but that is one difficulty.