When I state that multitasking is a myth, I am not talking about chatting to a friend on the phone whilst you stir a pot with one hand and close a cupboard door with your foot. I mean mental multitasking: we cannot pay proper attention to more than one thing at a time. The brain can only process one stream of information at a time. What we tend to do when we think we are multitasking (watching the football whilst reading a book, perhaps), is flick between the two. And each time we switch our focus from one thing to the other we have an “attentional blink”, which is a brief period when we are focused on nothing at all. If we try to multi-task a lot these attentional blinks can add up to quite a large block of wasted time.
You may protest that you are very good at multitasking, but just because you think you are does not make it so. Trying to focus on two separate things is asking one piece of apparatus (the “paying attention” part of the brain) to do two things at once. It is akin to trying to whistle and talk at the same time with just the one mouth.
I’m afraid the news gets worse. A study at Stanford University in 2009, conducted by Clifford Ness, split the participants into those who did regular “media multitasking” (watching TV whilst checking emails and Facebook, and so on) and those who didn’t. They were given a series of tasks and the regular multitaskers consistently made more mistakes. It appeared that they could not stop themselves from trying to monitor irrelevant information in their field of view; they could not focus properly on the task in hand.
If we feel guilty about something, washing our hands can help to assuage that guilt. It seems that physical washing cleanses us of our moral transgressions. This is known by psychologists as the Lady Macbeth Effect because of the way Macbeth’s wife, in the Shakespeare play, tries to scrub the imaginary blood off her hands.
It is possible that the effect is due to the prevalence of washing in religious rituals, or perhaps it is the other way round: maybe religious rituals include washing because of its effect on the psyche.
Many experiments have shown the power of the Lady Macbeth Effect, particularly several conducted by Zhong and Liljenquist.
One experiment had participants recall behaviour about which they felt ashamed. Half were then asked to wash their hands whilst the other half did not. All were asked, as they left the building thinking the experiment was over, to do a favour for a stranger. Those who had not washed their hands were much more likely to agree to the request because they had not washed their guilt away, and still felt they had to do something to atone.
Another experiment had participants tell a malicious lie either over the phone (using their mouths) or by email (using their hands). Those who had lied with their mouths later showed a preference for mouthwash over hand sanitizer, and those who had lied with their hands preferred hand sanitizer over mouthwash. The method of absolution thereby matched the sin.
Social psychologists love studying the effects of “priming”. This is where they subtly activate schemata we have in our minds without us noticing they have been activated. A schema is like a post-it note in our heads with our beliefs about a concept. For example, our schema for older people might be that they are wrinkled, grey-haired people who move slowly and may use walking aids. A psychologist may activate this schema in you by giving you verbal tasks to perform with some words thrown in which could be linked to old age.
Having a schema activated makes you quicker to recognise associated objects and words. Your schema for bananas might be activated by your being exposed to the words fruit, curved, yellow and so on, carefully placed amongst plenty of irrelevant ones. You will then more quickly recognise the word banana. You would also more quickly recognise (when reading or hearing) words and concepts you associate with bananas: perhaps fruit in general, monkeys, or even the jungle.
Having a schema activated can also make you behave in that way. For example, having rudeness activated made people more likely to interrupt an on-going conversation to ask a question. Bargh, Chen and Burrows found that people with their schema for old age activated subsequently walked more slowly.
Because, in the USA, people stereotypically go to Florida to retire, this effect became known as The Florida Effect.
Police, prosecution lawyers and defence attorneys all have an interest in questioning witnesses to crimes. That shouldn’t be a problem should it? In an ideal world, no. But in an ideal world they wouldn’t be able to alter our memories with the deliberately biased wording of their questions. This is not an ideal world though – and they can.
Loftus and Palmer, in 1974 showed participants a video of two cars colliding. They were then asked how fast the cars were going, but the exact wording was different for each experimental group. The question was “How fast were the cars going when they (smashed / collided / bumped / hit / contacted) each other. Those questioned with the word contacted estimated an average of just over 31mph. Those questioned with the word smashed guessed just over 40 mph. They all saw the same film, but the wording of the question altered their memory of it.
In a similar experiment people were asked the same question, but a week later were asked if there was broken glass on the road afterwards (there wasn’t). As you may have guessed, those who were originally questioned with the word smashed were, a week later, far more likely to misremember seeing broken glass.
Other experiments have shown that if a question such as, “Did the car stop before or after passing the tree?” is asked after watching a film, the memory of a totally non-existent tree can be implanted. That tree then becomes a part of the person’s memory and there is no way for them to backtrack and un-remember it.
Think about the implication for court cases where witnesses are first questioned by someone working for either the prosecution or defence.
Our memories are not fixed. The memory we have of any event does have, as its basis, some factual details which happened to get lodged in our brains. However, it also consists of a lot of gaps. We don’t usually notice the gaps because they are unconsciously filled in. To us it feels like a smooth, consistent memory which is the same as every other time we recalled it, but it actually could be very different from how it used to be.
When we tell an anecdote it is generally told for a reason. We tell the story to highlight a point, and to that end the gaps in our memory may be filled with convenient, though imagined, details. We are not usually aware of this happening, but it does. These details are then more likely to recalled next time the story is told, for whatever reason. Other, inconvenient, details may be left out and are then more likely to be left out again next time the story is told.
Not only does the anecdote change, but so does our actual memory.
Tversky and Marsh demonstrated this in an experiment. Their participants read a story about two roommates and then had to write an account of one of them, either positive, negative or neutral. After a short gap they were asked to recall the original story. Those who had written a positive account remembered more features consistent with the positive bias, as you might expect. But they also, unknowingly, elaborated, making the roommate appear in an even more positive light. And, of course, vice versa.
Those who wrote a neutral account made fewer errors and elaborated less. Unfortunately it is very rare that we tell a story with no bias whatsoever.
What we perceive is a mixture of what our senses receive and what our brains expect
In day to day life, we do not perceive an exact replica of the world outside. Instead, our expectations colour what our senses are telling us; what we finally perceive is a blend of reality and expectation.
Imagine you look at a playing card, the Ace of Spades, with a completely open mind. The light from the card gets focused, by your lenses, onto your retina. The patterns formed on your retinal cells get relayed to the back of your brain, which tells you there is a large black spade shape in the middle of the card and an A with a smaller spade on two of the corners. If you know how a pack of cards work, your brain recalls that the card with that pattern is the Ace of Spades. Up until the part where your brain recalls what that patterned card is, the process described is called bottom-up processing because all the data is coming from the basic perceptive organs – the eyes.
Now imagine you look at it convinced it is going to be the ten of hearts. The light is focused onto the retina and the messages are sent to the visual cortex in exactly the same way. However, this time your brain (fully expecting the ten of hearts and saving resources and time by not paying proper attention) ignores those objective signals. They don’t even make it to consciousness and your final perception is that the card is the Ten of Hearts. This is an extreme example, but you get the idea. This is called top-down processing because what you finally perceive comes straight from the top (expectation in the brain).
Normal everyday perception has to involve both bottom-up and top-down processing, so that we can not only sense our environment, but also understand it. However, if our senses are rushed or if we are not putting the effort into proper attention, top-down processing becomes more dominant. When this happens our expectations become more influential in our final perception, distorting what our senses are telling us. What we perceive is a mixture of what our senses take in and what we expect.
For example, Bruner and Postman showed people cards very quickly, some of which were doctored to be different (such as an ace of spades being red instead of black). Some participants simply took longer to recognise the card, but some perceived a red ace of spades as being purple, They expected black but saw red, so their brains mixed the two and they perceived purple.
This happens to us all the time in everyday life. What we perceive is a mixture of what our senses receive and what our brains expect.