Ways of studying the brain: scanning techniques, including functional magnetic resonance imaging (fRI); electroencephalogram (EEGs) and event-related potentials (ERPs); postmortem examinations.

What is fMRI?

• fMRI stands for functional magnetic resonance imaging.
• Brain scanning technique that measures blood flow and oxygenation in the brain.
• Detects changes in oxygenated blood linked to neural activity.

What is the Function of fMRI?

• Produces detailed 3D images of brain activity.
• Used to identify localisation of function in the brain.

What is the BOLD Signal?

• BOLD stands for Blood Oxygen Level Dependent signal.
• fMRI measures changes in oxygenated blood flow in active brain areas.

What is EEG?

• EEG stands for electroencephalogram.
• Measures electrical activity in the brain using electrodes attached to the scalp.

What is the Function of EEG?

• Detects brainwave patterns and electrical activity over time.
• Often used in sleep research and epilepsy studies.

What are ERPs?

• ERPs stand for event-related potentials.
• Specific brain responses linked to particular stimuli or events.
• Derived from EEG recordings.

What is the Function of ERPs?

• Measures brain activity related to cognitive processing.
• Allows researchers to investigate responses to specific stimuli or tasks.

What are Post-Mortem Examinations?

• Examination of the brain after death.
• Used to investigate relationships between brain structure and behaviour.

What is the Function of Post-Mortem Examinations?

• Allows detailed examination of damaged or unusual brain areas.
• Helped identify localisation of language areas such as Broca’s and Wernicke’s areas.

Difference Between Spatial Resolution and Temporal Resolution

• Spatial resolution refers to accuracy of locating brain activity.
• Temporal resolution refers to accuracy of timing brain activity.

Compare fMRI and EEG

• fMRI has high spatial resolution but low temporal resolution.
• EEG has high temporal resolution but poor spatial resolution.
• fMRI measures blood flow whereas EEG measures electrical activity.

Compare EEG and ERPs

• EEG measures general electrical activity in the brain.
• ERPs measure specific responses to stimuli or events.
• ERPs are derived from EEG recordings.

Compare fMRI and Post-Mortem Examinations

• fMRI studies living brains and measures ongoing activity.
• Post-mortem examinations study brains after death.
• Post-mortems allow more detailed physical examination.

fMRI AO3 — High Spatial Resolution

• fMRI has high spatial resolution.
• Can accurately identify which brain areas are active during behaviour.
• Improves understanding of localisation of function.

fMRI AO3 — Non-Invasive

• fMRI is non-invasive because it does not require surgery or penetration of the body.
• Reduces risk of physical harm to participants.

fMRI AO3 — Low Temporal Resolution

• fMRI has low temporal resolution.
• Cannot accurately measure the timing of brain activity because blood flow changes occur slowly.

fMRI AO3 — Indirect Measure

• fMRI measures blood flow rather than neural activity directly.
• Brain activity is inferred from oxygenated blood levels.

fMRI AO3 — Expensive

• fMRI machines are expensive to buy and maintain.
• Limits availability and number of participants studied.

EEG AO3 — High Temporal Resolution

• EEG measures brain activity in real time.
• Allows researchers to accurately study timing of neural activity.

EEG AO3 — Non-Invasive

• EEG uses electrodes attached to the scalp.
• Does not physically penetrate the brain or body.

EEG AO3 — Useful for Sleep Research

• EEG can identify different brainwave patterns during sleep.
• Useful for studying sleep stages and disorders such as epilepsy.

EEG AO3 — Poor Spatial Resolution

• EEG cannot accurately identify the exact brain area responsible for activity.
• Brain signals recorded from scalp are less precise.

ERP AO3 — High Temporal Resolution

• ERPs can accurately measure timing of cognitive processing.
• Useful for studying responses to specific stimuli.

ERP AO3 — Cognitive Processing Research

• ERPs allow researchers to investigate mental processes linked to particular events or tasks.
• Useful in cognitive neuroscience research.

ERP AO3 — Background Noise Problem

• EEG recordings contain unrelated brain activity.
• Difficult to isolate the exact response to a stimulus.

ERP AO3 — Requires Repeated Trials

• Many repeated presentations of a stimulus are needed.
• Helps average out background activity and improve reliability.

Post-Mortem AO3 — Detailed Examination

• Post-mortem examinations allow detailed physical study of brain structures.
• Useful for identifying damaged brain regions.

Post-Mortem AO3 — Useful for Rare Disorders

• Allows study of unusual or rare brain abnormalities.
• Contributed to understanding of localisation of language.

Post-Mortem AO3 — Cannot Establish Cause and Effect

• Difficult to know whether brain abnormalities caused behaviour or developed afterwards.
• Limits conclusions about causation.

Post-Mortem AO3 — Ethical Issues

• Some post-mortem examinations may occur without full informed consent.
• Raises ethical concerns about use of human tissue.

Post-Mortem AO3 — Retrospective Information

• Researchers rely on information collected before death.
• Historical information may be incomplete or unreliable.