Psychology Biological Approach SAQs

Explain one technique used to study the brain in relation to behavior with reference to one study. (theory)

MRI is a neuroimaging technique that produces detailed images of brain structure. The participant lies inside a scanner with a strong magnetic field, which aligns the hydrogen protons in the brain’s water molecules. Radio-frequency pulses knock these protons out of alignment. As they return, they emit signals that differ between grey matter, white matter and cerebrospinal fluid, and a computer turns these differences into a high-resolution image. Researchers can then compare the size or volume of brain regions between groups, or relate it to a behavior such as navigation or memory. MRI is non-invasive and involves no ionizing radiation. Its main limitation is that structural MRI shows what the brain looks like, not what it is doing, so it can only show correlations between structure and behavior, not

Explain one technique used to study the brain in relation to behavior with reference to one study. (the study)

Magnetic Resonance Imaging (MRI), illustrated by Maguire et al. (2000)

Explain one technique used to study the brain in relation to behavior with reference to one study. (Aim)

Maguire et al. (2000) aimed to investigate whether the hippocampus, which is associated with spatial memory, differs in structure in people who have extensive spatial navigation experience. They also asked whether the amount of experience is related to the size of the hippocampus.

Explain one technique used to study the brain in relation to behavior with reference to one study. (participants and procedure)

The sample was 16 right-handed male licensed London taxi drivers, with an average of about 14 years of experience. They had passed “The Knowledge,” a demanding test of London’s roughly 25,000 streets. The control group was 50 healthy right-handed males who did not drive taxis. Structural MRI scans were taken of all participants, and the scans were analysed using voxel-based morphometry, which compares grey matter volume across the whole brain. The researchers also measured the number of years each driver had worked as a taxi driver.

Explain one technique used to study the brain in relation to behavior with reference to one study. (results and link)

• Taxi drivers had significantly greater grey matter volume in the posterior hippocampus than controls.

• Taxi drivers had smaller grey matter volume in the anterior hippocampus than controls.

• Among the taxi drivers, time spent as a taxi driver correlated positively with right posterior hippocampal volume and negatively with anterior hippocampal volume.

The posterior hippocampus appears to store a spatial representation of the environment, and extensive navigation experience is associated with changes in its structure. The correlation with years of experience suggests the brain adapts in response to the behavioral demands placed on it, supporting the idea of neuroplasticity. This shows how MRI can be used to link a specific brain region to a specific behavior, spatial navigation.

Explain one technique used to study the brain in relation to behavior with reference to one study. (evaluation)

MRI gave Maguire et al. detailed, objective, quantifiable data on brain structure, which strengthens the reliability of the findings. However, the study is correlational, so it cannot establish that navigation caused the hippocampal differences. Taxi drivers could have had larger posterior hippocampi to begin with, which may have helped them pass The Knowledge. The all-male sample also limits generalizability.

Explain localization of function, with reference to one study. (Theory)