Ways of studying the brain

Ways of studying the brain

1. Event Related Potentials (ERPs)

   • A technique that takes raw EEG data and uses it to investigate cognitive processes of a specific event. It achieves this by taking multiple regions and averaging them in order to filter out unrelated brain activity.
     • STRENGTHS
       • It is possible to determine how processing is affected by a specific experimental manipulation, e.g. during presentation of different stimuli.
       • Can measure the processing of stimuli even in the absence of a behavioural response. The processing can be covertly measured without the person responding to the stimuli.
     • LIMITATIONS
       • ERPs are small and difficult to pick out from other electrical activity in the brain, so it requires a a large number of trials to gain meaningful data.
       • Only sufficiently strong voltage changes generated across the scalp are recordable - restricted to the neocortex.

2. Functional Magnetic Resonance Imaging (fMRI)

   • A technique used for measuring brain activity. It works by detecting changes in blood oxygenation and flow that indicate increased neural activity in a particular region of the brain.
     • STRENGTHS
       • Non-invasive - it does not expose the brain to potentially harmful radiation.
       • Offers a more objective and reliable measure of psychological processes than verbal reports.
     • LIMITATIONS
       • Indirect measure of neural activity - it only measures the changes in blood flow in the brain not the actual activity.
       • Overlooks the networked nature of brain activity, as it focuses only on localised activity.

3. Electroencephalogram (EEG)

   • A method of recording changes in the electrical activity of the brain using electrodes attached to the scalp.
     • STRENGTHS
       • Provides a recording of the brain in real time. This allows the researcher to accurately measure a particular task or activity with the brain activity associated with it.
       • Useful in clinical diagnosis - we can determine if someone having seizures is suffering from epilepsy by recording abnormal neural activity associated with epilepsy.
     • WEAKNESSES
       • Cannot reveal what is going on in the deeper regions of the brain such as the hypothalamus or the hippocampus, as it is unethical to implant electrodes into a human brain.
       • The EEG signal is not useful for pinpointing activity in the brain because electrical signal can be picked up by nearby electrodes. It doesnt allow researchers

4. Post Mortem Examinations

   • Ways of examining the brains of people who have shown psychological abnormalities prior to their death in an attempt to establish the possible neuarbiological cause for this behaviour.
     • STRENGTHS
       • Allow for a more detailed examination of anatomical and neurochemical aspects of the brain that wouldnt be possible using scanning techniques. Researchers can examine deeper regions of the brain.
       • Harrison (2000) - Researchers have been able to find evidence of changes in neurotransmitter systems and structural abnormalities of the brain associated with schizophrenia.
     • WEAKNESSES
       • Retrospective approach - limited because the researcher is unable to follow up on anything that arises from the post-mortem concerning a possible relationship between brain abnormalities and cognitive functioning.
       • Individual differences due to cause of death, age, progression of illness etc are all confounding variables to post-mortem research.