Blink and You Miss It

When you first survey a new environment such as when you enter a room for the first time (or any time, come to think of it) your senses are bombarded with information. The human brain is pretty amazing but even it can't take it all in. This means we sometimes miss important things. What is really impressive is that we don't miss more than we do. Psychologists want to know more about this mechanism. To find out, they have invented some ingenious experiments which have allowed them to tease out what the brain is doing at such times. In fact, the inventiveness of psychologists coming up with these experiments never ceases to amaze me.

To test this, Potter and Levy (1969) came up with the rapid serial visual presentation (RSVP) task. In its most basic form, a series of letters flash up one at a time in front of you. You're asked to look for an 'X' (T1). If you spot the X you then have to process it. This processing takes time and cognitive resources, thus creating a blindspot. Any letter (T2) presented within that blindspot gets lost and studies show this blindspot occurs between about 100ms and 300ms from the X (or whatever letter you're asked to look for). The phenomenon is called the attentional blink (AB).

So far so good. But psychologists were curious. Is it just that we can't see T2 at all or is it that we see it and process it in our brains but, for some reason, don't pay any attention it. Shapiro, Driver, Ward and Sorensen (1997) did something very clever. They had three target letters instead of just two. The second would be presented during the AB (the blindspot) and therefore go unnoticed by the participant. However, the twist was that they added a priming effect to T2 which would affect T3. What they did was in a stream of numbers, T2 would be a letter and T3 would be the same letter but in a different case. The idea was that if participants were more successful at noticing T3 if T2 had primed them toward it (as opposed to participants who were not exposed to the T2 as a primer) then it would suggest we really do process these things even if we say after that we didn't see them. Well, as I am sure you have guessed this is what they found.

Right, so now we know it is very likely we see things we don't notice and that we process them well enough that they can have an effect on other things we see. There was another study by Shapiro, Arnell and Drake (1991) which looked to see if colour was affected by the AB. It turned out it wasn't. So if you saw the X and then a colour was presented within the AB period you could report what that colour was. A few years later, though, another team of researchers (Ross & Jolicoeur, 1999) went a step further. They added a series of alternating colours after the first colour. They wondered if this created what they called chromatic masking. It did. In their experiment, the AB returned for participants who were asked to identify a colour when that colour was followed by others.

I included those two studies because it is a good example of how psychology (and science in general) works. The first study wasn't wrong. It researched a phenomenon and reported the results. But those results raised other questions and along came someone else who tried to answer them. That's how knowledge is built upon. But it is also what leads people to mistakenly believe that science is always changing its mind. It isn't.

There are lots of other studies which looked at the AB. Another one investigated what would happen when T1 was accompanied by a noise (Olivers & Van de Burg, 2008). What happened was that the AB vanished for T2. Another study (Shapiro, Caldwell & Sorensen, 1997) used the participant's name in T2 and that got through the AB as if it wasn't there. The same thing happens for emotionally negative words (Anderson & Phelps, 2001). The last of those studies had participants with damage to the part of their brain called the amygdala. It seems it is the amygdala which decides which stimuli are important and need to be passed on to higher processes and which can be safely discarded.

This goes some way to explain how it is we miss things but also why we tend to notice the really important things most of the time. So when you're driving you might not notice the marching band on the side of the road but you will notice the child bouncing a ball among a crowd of people.

Refs

Anderson, A. K., & Phelps, E. A. (2001). Lesions of the human amygdala impair enhanced perception of emotionally salient events.Nature, 411(6835), 305–309.


Ross, N. E., & Jolicœur, P. (1999). Attentional blink for color. Journal of Experimental Psychology: Human Perception and Performance, 25(6), 1483.


Shapiro, K. L., Caldwell, J., & Sorensen, R. E. (1997). Personal names and the attentional blink: a visual “cocktail party" effect. Journal of Experimental Psychology: Human Perception and Performance, 23(2), 504.


Shapiro, K., Driver, J., Ward, R., & Sorensen, R. E. (1997). Priming from the Attentional Blink: A Failure to Extract Visual Tokens but Not Visual Types.Psychological Science,8(2), 95–100.


Van der Burg, E., Olivers, C. N., Bronkhorst, A. W., & Theeuwes, J. (2008). Audiovisual events capture attention: Evidence from temporal order judgments.Journal of vision, 8(5), 2.

So What Is Psychology?

I thought I would dedicate my first blog post here to asking the question: what is psychology? The easy answer is that it is the study of the human mind, behaviour and feelings. After that it gets a little complicated. After all, there is clinical psychology, cognitive psychology, health psychology, developmental psychology, educational psychology . . . I will let Wikipedia take over from here. You're not here for a list, though. I assume you want my take on the matter or you would not be here at all. Well, here it is:

When I tell people I am studying psychology the response I get most often is 'You're not going to analyse me, are you?' When I feel mischievous I reply, 'I am analysing you right now.' However, the truth is, halfway through my second year I think I have only had one lecture on psycho-analysis. It's not that all of psychology has moved on from it; it's that psychology has grown so many branches since then and they all bear their own, individual fruits.

The biggest change in psychology was probably caused by the advancement of brain imaging, especially fMRI. Now we're able to look inside a living brain as its owner completes a task and see what's happening and where. That means we can begin to tease out how the brain works. We already had an idea that different parts of the brain performed different tasks, but there is so much coordination between brain regions that the overall picture is so incredibly complicated. For that reason, psychologists still need to come up with ever more ingenuous experiments to make sense of what is going on. Take the stroop test. Most of you should be familiar with what that is. It's where you have to say the colour a word is written in and not the colour the word is spelling out. So, for instance, if you see BLUE, you need to say 'green'. If you see RED, you need to say 'yellow'. This is difficult to do, especially quickly. But what is actually going on in the brain? Are we suppressing the word we are not supposed to say or are we promoting the word we are supposed to say? To answer that, someone very clever (Tipper, 1984) tweaked the experiment: they arranged the words so that each colour you're supposed to say was the colour you weren't supposed to in the preceding word. So, RED is followed by GREEN. Here, the word you want to say but are not supposed to is 'red' but the next word you are supposed to say is 'red' as well. The experimenters said that if you were suppressing the word 'red' then you would take longer to say 'red' when you are supposed to. If you were just promoting the correct word that would not have any effect. What they found was that participants took longer to say the correct colour when it was preceded by the same word that they weren't supposed to say. It's a very simple experiment but it allows us to say that, probably, we suppress things we're not supposed to say instead of promoting the words we are.

That's what psychology is. At least for me as a student most of the time. We're interested in what the brain is doing. Except when we're not. I am currently involved in some research that involves analysing conversation and looking for patterns in the way we report problems. That involves watching hour upon hour of videos of families eating dinner and transcribing anything that resembles what we're looking for. There are no fMRIs and no clever experiments: just lots and lots of watching and listening. Which is not to say it is not incredibly methodical. Conversation analysis uses a type of transcription called Jefferson. This allows us to break down conversation into recognisable and predictable parts so that we can see what language does as opposed to what it means. We're not trying to imply cognitive processes; we're trying to work out how we construct language to make it do what we want it to do. Why? Well, when a child calls a helpline to report abuse it really pays to know how best to coax out the information you need as quickly and as accurately as possible. However, while I am doing that, a few doors down the corridor, two of my friends are sticking their hands into icy water and seeing if swearing enables them to stand it for longer (Stephens, Atkins & Kingston, 2009).

I may not have helped you to understand what psychology today is. I hope, though, I have gone some way to helping you appreciate how broad and inventive it is. That should come as no surprise. We're trying to understand the human mind, which is still the most complicated thing we know of in the universe.

Refs.

Stephens, R., Atkins, J., & Kingston, A. (2009). Swearing as a response to pain. Neuroreport, 20(12), 1056-1060.

Tipper, S. P. (1985). The negative priming effect: Inhibitory priming by ignored objects. The Quarterly Journal of Experimental Psychology, 37(4), 571-590.

Introduction

Eighteen months ago I started a degree in English and psychology at Keele university in the UK. A lot has happened since then. One of those things was entering a Wellcome Trust science writing contest. The lecturer I entered with, Dr Richard Stephens, won and he encouraged me to submit my effort for publication elsewhere. I passed it around and got interest from The Psychologist no less.

I was a journalist before enrolling at university and I had an idea back then I would write about psychology in the future, making it accessible to people, clearing up misconceptions and sharing in some of the fascinating things I have learnt and am still learning every day. The communication of science, in general, is something I have always admired in those who do it well. I also think it is a valuable endeavour. After all, we're all human, and understanding why we do, think and feel the things we do has got to be worth it. For instance, why do we swear when we are in pain? How do parents really react when their children report a trouble to them? What causes us to walk into a room and forget why we are there? And do mamals really urinate for an average of twenty-one seconds? Answers to these questions and more will be offered in the coming weeks, months and, hopefully, years.

(If you have a question about psychology then feel free to ask it. If I don't know the answer I will find out for you.)

Richard