Physiological Psychology Studies
The physiological approach to psychology focuses on our biological make up, and the events that occur in our bodies which cause our behaviour. Mainly, therefore, psychological psychology will focus on the brain, but it will also include study of the nervous system, hormones and genetics.
Strengths of the Physiological approach
The approach has revealed that a number of areas of the brain have specific functions. For example, Maguire's study of taxi drivers shows that the hippocampus is crucial in memory of routes. This clearly has many useful applications for diagnosing and treating people who have problems after brain damage.
The approach is very scientific. It performs very carefully controlled experiments which are therefore likely to be replicable and produce reliable results.
The physiological approach can take advantage of sophisticated equipment such as PET and MRI scanners which provide an objective and precise way of measuring brain structures. For example in the Maguire et al. study the researchers were able to scan living brains using PET and MRI technology which enabled the researchers to gain lots of quantitative and objective data about the density of the grey matter of the hippocampus. Dematte used the olfactometer which enable strict control over the intensity of odors.
Weaknesses of the Physiological approach
Even though this approach tries to be scientific, it is often impossible to directly observe the psychological processes we want to. For example, we cannot measure thoughts, so instead we have to measure things like blood flow. An increase in blood flow may not be the same as a change in thought processes.
Our limited ability to study brain processes directly and objectively means we often have to rely on self-report data, and so demand characteristics may be a problem. For example, in Dement and Kleitman’s study, subjects could have falsified reports about whether or not they were dreaming, or falsified the content of their dreams.
Studies carried out in the laboratory can be low in ecological validity. Dement and Kleitman had subjects spend the night in a sleep laboratory. We sleep differently when we are not in our own beds, and this certainly must have been the case since each subject was not only in a strange bed, but was wired up to an EEG machine, woken by a doorbell at intervals throughout the night and observed. Schacter and Singer injected participants to induce physiological arousal and this is clearly artificial and not a typical every day experience. Furthermore, the laboratory surroundings lacked ecological validity and the situation of experiencing unexplained physiological arousal is rare.