🧠 Techniques Used to Study the Brain in Relation to Behaviour

📌 Definition Table

Term	Definition
Neuroimaging	The use of technology to view brain structure and activity non-invasively.
MRI (Magnetic Resonance Imaging)	Produces 3-D images of brain structure using magnetic fields and radio waves.
fMRI (Functional MRI)	Measures blood-oxygen levels (BOLD signal) to show brain activity during cognitive tasks.
PET (Positron Emission Tomography)	Uses a radioactive tracer to measure brain metabolism and activity.
EEG (Electroencephalogram)	Measures electrical activity across the brain’s surface using electrodes.
CT (Computed Tomography)	Combines X-ray images to show cross-sectional brain structure.
Spatial Resolution	The ability of a scan to identify precise brain locations.
Temporal Resolution	The accuracy of a scan in detecting timing of brain activity.
Triangulation	Using multiple techniques to validate findings and strengthen conclusions.

📌Core Concepts
Studying the brain is fundamental to understanding the biological basis of behaviour.
Modern neuroscience employs various techniques that allow researchers to link brain structure and activity to psychological processes such as memory, emotion, and decision-making.

Each method varies in resolution, invasiveness, cost, and ethical implications, and together they help provide converging evidence for theories such as localization of function and neuroplasticity.

Overview of Major Techniques

MRI (Magnetic Resonance Imaging)

• Uses strong magnetic fields and radio waves to produce high-resolution images of brain anatomy.
• Provides structural data — excellent spatial resolution, but no information on activity.
• Safe and non-invasive (no radiation).
• Commonly used in localization research (e.g., Maguire et al. 2000).

fMRI (Functional Magnetic Resonance Imaging)

• Builds on MRI technology by measuring changes in blood oxygenation (BOLD signal) as an indirect indicator of neural activity.
• Excellent spatial resolution, moderate temporal resolution.
• Used in studies examining memory, attention, and emotion (e.g., Antonova et al. 2011).

PET (Positron Emission Tomography)

• Participants ingest a radioactive glucose tracer.
• Scanner detects where glucose is metabolized — indicates active brain areas.
• Good for comparing brain activity across conditions; lower spatial and temporal resolution than fMRI.
• Invasive and expensive — used less often today.

EEG (Electroencephalogram)

• Electrodes placed on the scalp measure electrical activity generated by neuron firing.
• Excellent temporal resolution, poor spatial resolution.
• Useful for sleep, attention, and reaction-time studies.

CT (Computed Tomography)

• Uses X-rays to form cross-sectional images of brain structure.
• Useful for detecting brain injury or abnormalities but provides limited detail about soft tissue.

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📌Key Studies

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Maguire et al. (2000) – MRI

• Aim: Investigate whether taxi drivers’ spatial navigation experience altered brain structure.
• Method: MRI scans compared London taxi drivers to control participants.
• Findings: Posterior hippocampi were significantly larger in taxi drivers; correlated with years of experience.
• Conclusion: Spatial memory and navigation are localized to the hippocampus.
• Demonstrates: Localization + Structural imaging (MRI).

Antonova et al. (2011) – fMRI

• Aim: Examine acetylcholine’s role in memory.
• Method: Participants injected with scopolamine or placebo; performed spatial memory task in fMRI scanner.
• Findings: Scopolamine reduced hippocampal activation.
• Conclusion: Acetylcholine modulates hippocampal activity in memory encoding.
• Demonstrates: Neurotransmission + Functional imaging (fMRI).

Rosenzweig, Bennett & Diamond (1972) – Animal Research

• Rats placed in enriched vs. deprived environments.
• Post-mortem analysis showed thicker cortices in enriched group.
• Though not imaging, serves as historical evidence for neuroplasticity prior to modern scanning.

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⚖️ Evaluation of Techniques

Technique	Strengths	Limitations	Ethical Issues
MRI	High spatial resolution, non-invasive, reliable structural data	Expensive, movement can distort image, cannot infer causation	Minimal — requires consent and screening for metal implants
fMRI	Maps active brain areas in real time, no radiation	Poor temporal resolution, indirect measure of neural activity	Claustrophobia, motion restriction
PET	Measures metabolic activity, useful in clinical diagnosis	Invasive (radioactive tracer), expensive	Radiation exposure — limited use in minors
EEG	High temporal precision, inexpensive, non-invasive	Poor spatial localization	None significant beyond consent
CT	Detects structural damage quickly	Radiation exposure, low soft-tissue detail	Radiation — caution required