L9 - Studying The Brain

Question 1

What are Post-Mortem Examinations?

Answer 1

A person who displays interesting behaviours while alive dies. A psychologist looks for abnormalities in the brain that could explain their behaviour.

The studies have found a link between brain abnormalities and psychiatric disorders e.g reduced glial cells in the frontal lobe is evidence for depression

Question 2

Post-Mortem Examinations Evaluation

Answer 2

+ Allow for detailed examination of anatomical and neurochemical aspects of the brain than other methods. Enabled researchers to examine deeper e,g hippocampus and hypothalamus

• Can lack validity because of small sample size, and because people die in a variety of circumstances. It can also be affected by length of time between death and examination as well as drug treatments

Question 3

What is Functional Magnetic Resonance Imaging (fMRI)?

Answer 3

• Uses magnetic fields and radio waves to monitor blood flow in the brain.
• It measures the change in the energy released by haemoglobin, reflecting brain activity to give a moving picture of the brain.
• Activity in regions of interest can be compared during a abase line task and a specific activity

Question 4

Functional Magnetic Resonance Imaging Evaluation

Answer 4

+ Captures dynamic brain activity unlike MRI/Post-Mortem which only shows physiology

• fMRI interpretations are complex and is affected by temporal resolution, biased interpretation and by the base line task used.
• fMRI research is expensive and causes reduced sample sizes which affect the validity negatively

Question 5

What is an Electroencephalogram? (EEG)

Answer 5

• Measures GENERAL electrical activity in the brain such as sleep and arousal.
• Electrodes are placed on the scalp to detect neuronal activity below where they are placed
• When the signals are trained over a period of time, an EEG pattern is formed, e.g epileptic patients have spikes of electrical activity

Question 6

Evaluation of Electroencephalogram

Answer 6

+ Useful in clinical diagnosis, can confirm diagnosis e,g epilepsy.
+ Cheaper than fMRI so can be used more widely

• Poor spatial resolution

Question 7

What are Event-Related Potentials?

Answer 7

• Electrodes are placed on the scalp and detect neuronal activity in response to a SPECIFIC stimulus introduced by the researcher.
• hardest to pick out from all electrical activity generated
• To establish a target response to a target stimulus, requires many presentations of this stimulus and the responses are averaged together.
• Any extraneous neural activity that is not related to the specific stimulus will not occur consistently
• ERP waves generated in the first 100 milliseconds after a stimulus is presented are termed sensory ERPs as they reflect the initial response to the physical characteristics.
• ERPs generated after the first 100 milliseconds reflect the manner in which the subject evaluates the stimulus and are called cognitive ERPs as they demonstrate information processing

Question 8

Evaluation of Event-Related Potentials

Answer 8

+ ERP can measure the processing of a stimulus even in the absence of a behavioural response, therefore it is possible to measure covertly.

• Only sufficiently strong voltage changes generated across the scalp are recordable. Important electrical activity occurring deeper in the brain is not recorded. The generation of ERPz tends to be restricted to the neocortex