Discuss Ways of studying the brain (16 marks) (Model Answer)
There are several techniques used to study the brain, including fMRI, EEG, and post-mortem examinations, each with distinct advantages and limitations.
fMRI (Functional Magnetic Resonance Imaging) measures changes in blood oxygenation while a person engages in a task. This allows researchers to infer which areas of the brain are more active, producing images with high spatial resolution (down to the millimetre). This is particularly useful in investigating localisation of function, for example activity in Broca’s area during speech tasks. fMRI therefore provides a non-invasive way of studying living brains in action. However, while spatial resolution is strong, temporal resolution is relatively poor—there is a delay of several seconds between neural activity and the blood-flow changes detected. This makes it difficult to establish precise timings of brain processes, limiting conclusions about causality. In addition, fMRI is expensive and requires participants to remain very still, reducing accessibility and ecological validity.
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👉 Download Examiner FeedbackEEG (Electroencephalogram) involves electrodes placed on the scalp to measure electrical activity from populations of neurons. The major strength of EEG is its very high temporal resolution (milliseconds), allowing researchers to track brain activity in real time and link responses to specific stimuli. This makes EEG particularly valuable for studying processes such as epilepsy, sleep, and event-related potentials (ERPs). However, EEG has low spatial resolution; the activity recorded reflects thousands of neurons, and the precise source of signals cannot be pinpointed. This means conclusions about localisation are less accurate than fMRI. Nevertheless, EEG is relatively inexpensive, non-invasive, and widely used in both research and clinical contexts, making it a practical and ethically sound technique.
Post-mortem examinations involve analysis of the brain after death, often comparing abnormalities with behaviour shown in life. A classic example is Broca’s work with patient Tan, who could not produce speech and was found to have damage to the left frontal lobe. Post-mortems allow for highly detailed anatomical examination not possible with other techniques, providing insights into brain structure and pathology at a microscopic level. However, they cannot show brain activity in real time, and cause-and-effect inferences are limited: abnormalities found may not be linked to observed behaviours, and changes could be due to unrelated factors such as disease or medication. Ethical concerns can also arise, though these are less significant than with living participants since consent is typically obtained before death.
In synthesis, each technique offers unique contributions. fMRI is powerful for localisation with precise spatial maps, EEG is strong in identifying rapid neural processes in real time, and post-mortems provide anatomical detail unavailable elsewhere. The most effective method depends on the research question: for example, EEG is ideal for studying fast responses, fMRI for mapping functions, and post-mortems for linking structural damage to behaviour. A comprehensive understanding of the brain often requires combining these approaches, as no single method is sufficient alone.