Physiological psychology focuses on the relationship between our biological makeup and our behaviour and experiences. This area of psychology can be very convincing. For example we do know that the structure of our nervous system (including our brains) and the action of chemicals can have an effect on our behaviour. 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 led to such psychologists making great discoveries, for example, in the affect of drugs on mood and behaviour. However, other psychologists (including many physiological psychologists) take the view that we cannot explain complex human behaviour and experience just in terms of brain structure and chemicals. There are other psychological variables which need to be considered, for example, how we act alone, compared to how we behave in groups. Maguire
* That the structure of the brain changes in response to environmental demand. * That the mental map of the city of London is stored in the posteria hippocampi in taxi drivers. * That normal activity can induce changes in the structure of the brain and that this has many implications for rehabilitation after brain injury.
The sample is not representative as it only contains 16 males in each group. Further research would need to include females and left-handed individuals.
This study does not have any serious ethical issues. However, the non-taxi drivers probably were unaware that their brain scans were being used, although they had probably signed a general medical disclaimer at the time of scan. But, using a brain scan as a comparison is not really an issue. This was a highly controlled experiment, therefore it is replicable. The results are reliable as the expert analysing the scans did not know which were the taxi driver scans. However, it would be better to conduct a longitudinal study, so that changes to brain structure over time could be traced.
This study does lack validity as it only considers one factor, the volume of the hippocampi, in relation to navigational skills. In reality it is likely that this complex memory skill is governed by many separate areas of the brain.
This study suggests that training can affect brain structures; this has clear implications for the treatment and therapy of brain damaged patients.
Alternatively, it could be argued that these taxi-drivers always had differences in their hippocampi, and that it was this that led them to become taxi drivers. In other, words they were naturally better at navigation, and therefore became taxi-drivers.
Dement W & Kleitman
The authors conclude that this research provides support for the idea that dreams can be studied in an objective way. This then open up other areas of research e.g. investigating the effects of environmental stimuli, stress and drugs on dreaming.
An obvious weakness of the study is its lack of ecological validity. The situation in which the participants had to sleep was unusual and could have affected their sleep patterns. Also the nature of the method of waking participants may have affected their ability to recall their dream.
A further problem with the study was sample size. The sample size was small and only included 2 females so we could argue that the results were biased towards the dream patterns of men rather than women.
Subsequent studies have found that there are large individual differences in the reports of dreaming during REM.
Subsequent studies have not supported Dement & Kleitman’s findings that there is a relationship between eye movements and what the person is dreaming about.
However, the method was very tightly controlled. For example, the researchers were able...