How quickly can you detect changes in the environment?

What are we studying?

Most humans are highly dependent on vision when interacting with the world. Vision feels like an effortless process -- we just open our eyes and immediately "see" everything around us. In realilty, there is so much information entering our visual system at any given moment that we cannot possibly process it all at one time without overwhelming our visual system.

Fortunately, not all of the visual information around us is relevant at any given moment. If you are crossing a road, for example, it is essential that you see the cars, but it's not very important that you see the surrounding trees, birds, or buildings. So, your visual system needs a way of selecting just the relevant visual information for processing while ignoring or filtering out the irrelevant information. This selective process is what we call attention.

Attention researchers often use a simple metaphor to talk about attention: we say that attention is like a spotlight. Imagine yourself in a dark theater. Suddenly a spotlight is turned on and illuminates an actor on the stage. You can now see this actor and can see details of their clothing or facial expressions. Everything else on the stage that is not lit up by the spotlight, however, you won't be able to see very well. Attention works in much the same way: if you are paying attention to something (your attentional spotlight is on it), you will be able to see and process it. Everything else will be unattended and ignored. So, if your attentional spotlight were deployed as in the image below, you would be attending to the motorcyle and able to process it clearly, but everything else would be unattended.

We can move our attentional spotlight around: in the video below you can see how you might move your attentional spotlight if you were driving along this busy road. First your attention might be focused on the motorcycle driving up between the lanes, then it might shift over to the car changing lates, and finally to the police car.

In our research, we are interested in (a) what factors cause you to change where you are paying attention and (b) how quickly you can move your attention. Depending on which exact experiment you took part in, we manipulated the size of the objects to see how that changes your attention, we manipulated how long you had to shift attention by changing how long objects were displayed for, and manipulated how far you had to shift attention by changing the spatial separation between objects.

How do we measure where you are paying attention?

We can measure where you are paying attention by presenting targets at different locations on the screen (target location is an independent variable) and by measuring how quickly and accurately you respond to the target (reaction time and accuracy are both dependent variables). If you are paying attention to a location, your responses to a target appearing there will be faster and more accurate than if you are not paying attention to that location.

Why does this matter?

Even if you are looking right at something, unless you are also paying attention to it, it will not reach your conscious awareness. It's easy to find the effects of attention in daily life: inattention or paying attention to the wrong thing is the 2nd leading cause of fatal car accident on Australian roads. So, if we can better understand where people pay attention and how quickly they can change where they pay attention, we will be better able to identify risky situations and risky drivers and may also be able to develop strategies to help people improve their attention while driving.

Curious to learn more about attention or visual cognition? Here are some books that you might enjoy:

• Chabris, C. F., & Simons, D. J. (2010). The invisible gorilla: And other ways our intuitions deceive us. Harmony.

• Doidge, N. (2007). The brain that changes itself: Stories of personal triumph from the frontiers of brain science. Penguin. (Available as an e-book in the City of Gold Coast public library via Overdrive)

• Kahneman, D. (2011). Thinking, fast and slow. Macmillan. (Available as an e-book in the City of Gold Coast public library via Overdrive)

• Gladwell, M. (2006). Blink: The power of thinking without thinking. (Available as an e-book in the City of Gold Coast public library via Overdrive)