Understand Psychology

by Nicky Hayes

We can change the chemical balance in the brain,

a bit like standing outside a factory and trying to guess what they are making by listening to the noises coming through the window. Studying the brain in this way doesn’t tell us everything, by any means. But it can show us something about the overall patterns of activity, and one of the things it can show us is the general patterning of brain activity when we are in different states of consciousness.

When we are relaxed, an EEG trace shows quite large waves of electrical activity (large for the brain that is). These are known as alpha rhythms. We produce them just before we drift off to sleep, or when we are daydreaming or just relaxed and happy.

concentrating hard, though, the EEG trace shows a different kind of activity. There are still detectable rhythms in its pattern, but they are smaller and closer together. These are known as delta rhythms.

when we are just generally awake, neither relaxing nor concentrating, the EEG trace doesn’t show any regular rhythms at all. Instead, it shows continuous intensive activity with no particular pattern (see Figure 5.3

Scanning the brain

PET scan (short for positron emission tomography) involves looking at how much blood is being used by a particular part of the brain. Each time a nerve cell fires, it uses up some nutrients, and so it needs to replace them from the blood supply. So parts of the brain which are being active need a larger blood supply than those which aren’t.

PET scan allows a psychologist or doctor to see which parts of the brain are using most blood. It works by ‘labelling’ the blood using a special radioactive chemical which can be detected by the scanner.

different images from the ‘slices’ are then combined using a computer. This can highlight areas of deformed or damaged tissue, such as blood clots or regions where the blood supply has been interrupted. So CAT scans can help us to identify exactly where a problem is located.

still a long way from getting a comprehensive understanding of what is going on. Nonetheless, researchers are slowly building up a picture of some of the principles of how the brain works, and which parts do what.

Sleep and dreaming

1930s, psychologists began to use EEGs to record brain activity, and when EEGs were taken during the whole of a night’s sleep, researchers found that actually the brain is extremely active, even if the body seems to be quiet.

Level 2 sleep still shows rapid and irregular activity, but with greater changes in the voltage becoming apparent from the peaks and troughs on the chart. Also during this level of sleep, patterns known as spindles begin to appear, which are very rapid, changeable bursts of activity.

Sleep cycles

6 Motivation

homeostasis – maintaining the appropriate balance in the body so that we can function well, physically.

is,

studies with animals, they would eat until they had consumed enough food to reach their set weight, and then stop eating. Even if they went on a restricted diet for a while, so they lost weight, as soon as the restrictions were off they would eat enough to return to the set weight.

might explain why so many people have problems with dieting. They are trying to achieve a weight that is lower than the physiological set weight which their body functioning is based on.

affected by other kinds of motives:

dieting, for instance, has more to do with social approval than it does with physiological needs,

people often drink even non-alcoholic drinks to be sociable rather than because t...

Behavioural motives

Sometimes, what we do comes about as much because of habit as anything else.

Habits are behaviours or feelings that are associated with particular settings or situations.

We learn how to act in certain places, or with certain people, and these come back to us if we find ours...

usually worried and anxious when they go into an exam room to take an exam. Because we don’t usually have anything to do with them at other times,

same thing can happen, too, with interpersonal relationships.

example, if you meet someone that you haven’t seen for a while, you can find yourself slipping back into ways of behaving with them that aren’t typical of the way that you behave with other people.

We don’t find it hard to change our habits when our situations change. So a good start for getting rid of a bad habit is identifying the particular situations which trigger it off, and changing them. If there are lots of situations, change one at a time.

The way that we think also sometimes motivates us into action.

formed our own personal theories about what other people are like from the way that people have interacted with us in the past. These theories are called personal constructs and we use them when we meet new people.

‘kind – cruel’

‘hot-tempered – calm’,

‘interesting ...

As a general rule, we tend to use about eight or ten main personal constructs most often, but we have several less important ones as well. Whenever we meet someone new, we weigh them up on the basis of our own personal construct system. Then we use those judgements to decide whether we like them or not.

Individual explanations

Two people could meet a third person for the first time, and even though they were together and had the same objective experience, they might come to very different conclusions.

Social expectations

If you have a set of personal constructs which mean that you treat anyone new as if they were not really friendly but had some ulterior motive for pretending to be so, then they will react to how you are behaving towards them, and avoid you. You would take that as ‘proof’ that they weren’t really being friendly, not realizing that it was your own behaviour which had produced that effect.

Many psychologists use personal construct theory to help people whose belief systems have become stuck like this. They use techniques that will help people to develop a new set of personal constructs,

Believing in your own capabilities is an important part of positive thinking. It’s actually better to overestimate your abilities than to underestimate them, because that means you will try harder, and so will be more likely to succeed.

DEFENCE MECHANISMS

Many psychologists are deeply sceptical about the ideas of Sigmund Freud,

who developed a theory about the unconscious mind during the last century.

But Freud did identify some important mental processes which the mind uses to protect itself against threats. The...

example, if we are faced with an awkward or uncomfortable fact about ourselves, our first impulse may be simply to deny that it is true. Sometimes, we will be able to get beyond that first impulse and see that the idea does, perhaps, have some justification. At other times, though, the implications of the idea may be too much for us to cope with. So we stick to our denial, even though it may be quite irrational, simply because we are protecting ourselves from having to rethink all our beliefs and ideas.

mechanism is unconscious

Their homophobia often comes from their own unconscious homosexual desires, which have been repressed so hard that they have become a reaction-formation.

these are very important, because they affect how hard we try.