How to answer a Describe SAQ (DP IB Psychology)

Describe one technique for studying the brain, using relevant research to support your answer. [9 marks]

Commentary

MRI (magnetic resonance imaging) is a non-invasive test used to diagnose medical conditions and to measure grey matter in specific brain structures. MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed three-dimensional images of the brain. The researcher compares the size and distributions of the bright and dark areas on the scan to detect brain structure anomalies e.g., injury, stroke, dementia.

Maguire (2000) used MRI to compare the brains of London black-cab taxi drivers (16 participants) and non-taxi drivers (50 pre-existing matched scans). The resulting scans were analysed by a blind expert using voxel-based morphometry (VBM) to measure grey matter volume in brain structures. Pixel-counting was also used to calculate hippocampal volume: pixels were counted on photographic ‘slices’ made through the brain using an MRI scan. Pixels were counted for the

anterior, posterior and body of the hippocampus.

Maguire found increased grey matter in the posterior hippocampus of taxi drivers and increased grey matter in the anterior hippocampus of non-taxi drivers. The use of MRI enabled her to conclude that years of experience had enhanced the spatial navigation skills of taxi drivers, which in turn had led to neuroplasticity in the posterior hippocampus. Such a conclusion was only possible due to the use of MRI as it measures brain structure in specific regions.

The technique is identified immediately and described using some detail.

Relevant research focused on the study's use of the technique. Other study details that are not relevant to the question should not be included.

The findings are outlined with reference to the relevance of the technique used in the study.

The conclusion links back to the question and the use of the technique.

Word Count: 222 words

[9 marks]