Physiological Approach

Physciological psychology focuses on the relationship between our biological makeup and our behaviour and experiences.

An explanation of the approach is that all that is psychological is first physiological - that because the mind appears to reside in the brain, all thoughts, feelings and behaviours ultimately have a physciological cause. Nerves and neurotransmitters are the hard wiring on which behaviour is based.

The physiological approach provides a strong counter-arguments to the nurture side of the nature-nuture debate. 

This area of psychology can be very convincing. For example, we do known that the structure of our nervous system (including our brains) and the action of chemicals can have an effect on our behaviour. However, an important question is how much does our biology affect us?

Some physiological psychologists take a reductionist argument to answer the above question. That is, they argue that behaviour and experiences can be explained in terms of brain structure and chemicals. This reductionist argument has lead to such psychologists making great discoveries, for example in the affect of drugs on mood and behaviour. 

However, other psychologists (including may physiological psychologists) take the view that we cannot explain complex human behaviour and experiences just in terms of brain structure and chemicals. There are other psychological variables which need to be considered, for example, such as how we act alone compared to how we behave in groups. 

1. An implication of the Physciology Approach, is that it can be expensive because specialist equipment and trained operators are required which can be costly. 

2. Often only small samples are used due to the fact of it being substancial in cost, this then limits the ability to generalise the sample. 

3. Behaviour problems are able to be treated by drugs as causes are biological due to an imbalance of body chemicals. 

Maguire et al. (2000) - The study by Maguire et al. investigates the relationship between a structure of the brain called the hippocampus and memory.

Dement and Kleitman (1957) - This study investigates what happens when we sleep.

Sperry (1968) - Sperry's study, investigates the behaviour and experiences of people who have had their brains (corpus callosum) separted into the left hemipshere and the right hemisphere. 

The main assumption of the physciological approach is therefore that behaviour and experience can be explained by physiological changes. This approach investigates the brain, the nervous system and other biological factors such as hormones. 

A main strength of the physciological approach is the use of sophisticatd equipment such as MRI scanners, which provide an objective and precise way of measuring brain structure. 

For example in the Maguire et al. (2000) study, the researchers were able to scan living brains using MRI technology which enabled the researchers to gain lots of qunatitative and objective data about the density of the grey matter of the hippocampus.

Furthermore, the physiological approach takes a scientific approach using laboratory type experiments. 

For example, in Dement and Kleitmans study of sleep and dreaming, the participants were studied under tightly controlled conditions. 

A further strength of the physciological approach is the practical applications that is offers. Much of the research in this area is very useful as it may be used to diagnose and develop treatments and therapies for illnesses or problems. 

For example Maguire et al. suggested that their study has implications for those who have suffered brain injury on disease because the demonstrate the plasticity of the brain. 

Dement later in studies had demonstrated the importance of sleep in relation to mental health. However, the main applications of the physiological approach have been the development of anti-depressant drugs which are more controversial partly because of the side effects that may occur. Furthermore, the idea that changing a chemical in the brain will bring about changes in complex emotions is a reductionist one as depression probably involves other life events.

A problem with the physiological approach is that by using such a scientific approach and testing behaviour in laboratory conditions the measurement of behaviour often lacks validity. For example, Dement and Kleitman measured sleep in laboratory conditions which is not typical of how people normally sleep. Therefore asking people to sleep with electrodes attached to their scalp and face is low in ecological validity. Similarly Sperry’s participants were asked to complete unusual tasks which again are not typical of everyday behaviours. However the use of this laboratory approach does mean that the researchers have more control of their procedures ensuring that extraneous variables can be controlled 

A further problem with the physiological approach is that because such studies can be costly and time consuming because of the use of sophisticated equipment and lengthy procedures. This often leads to such studies having small samples such as the Dement and Kleitman study which only studied 5 participants in depth. It is possible to argue that such a sample is not representative and therefore we should be careful generalising the results. Furthermore, Sperry was only able to 11 participants because he had a very limited number of participants to choose from, that is participants who had undergone disconnection of the cerebral hemispheres. However the increasing availability of MRI scanners is enabling researchers such as Maguire to increase their sample sizes and in subsequent studies Maguire et al. have been able to scan the brains of many more participants enabling the researchers to have a large database of many more brain scans to choose from.