Brain-imaging techniques
IB Psychology· Biological approach· 14 min read
1. Core concept
Brain-imaging techniques let researchers see the working brain without surgery. fMRI tracks blood-oxygen changes as a proxy for neural activity (good spatial detail); PET uses a radioactive tracer; EEG records electrical activity with excellent timing but poor location. They are used to link functions to regions and to compare groups. Crucially they show correlation — this area is active while X happens — not proof that the area causes X, and the artificial scanner setting can lower ecological validity.
2. Key studies
IB Psychology answers must be supported by named studies. Learn these to cite as evidence:
Saxe & Kanwisher (2003)
fMRI showed the temporo-parietal junction (TPJ) activated when people reasoned about others' beliefs. — Imaging links a social-cognitive function (theory of mind) to a specific region.
Sharot et al. (2007)
People closer to the 9/11 attacks showed selective amygdala activation when recalling the event. — Imaging supplies a biological correlate of emotionally-charged 'flashbulb' memory.
3. Evaluation (AO3)
Strength — objective, non-invasive map — Gives a replicable spatial picture of activity that self-report cannot, safely and in living participants.
Limitation — correlational & artificial — Activity co-occurring with a task is not proof the region causes it; lying still in a scanner is low in ecological validity, and fMRI has poor temporal resolution.
4. Scope
5. Common Pitfalls
Wrong move:
A scan shows the area that 'causes' or is solely 'for' the behaviour.
Why:
A frequently penalised misconception in IB Psychology exams.
Correct move:
Imaging shows co-occurring activity — a correlation. Causal claims need converging lesion or stimulation evidence.
Going deeper
- Localization of functionimaging is the main evidence base for localization of function (BIO_7).