ways of studying the brain

Question 1

fMRI - functional magnetic resonance imaging

Answer 1

• changes in brain activity measured while performing a task
• changes in blood flow in particular areas of the brain are measured, changes indicate increased neural activity in those areas
• as an area becomes more active it demands more oxygen resulting in increased blood flow to that area
• researchers able to produce maps showing which areas of the brain are involved in particular mental activity
• temporal resolution, 1-4 seconds
• spatial resolution, 1-2 mm
• doesnt use radiation, risk free
• doesnt provide direct measure of neural activity, measures change in blood flow

Question 2

ECG - electroencephalogram

Answer 2

• ECG measures electrical activity in the brain
• electrodes placed on scalp detect electrical charges resulting from activity of brain cells
• electrical signals from different electrodes graphed over a period of time
• temporal resolution, every millisecond
• spatial resolution, only detects activity in superficial/general areas of brain
• doesnt involve inserting electrodes directly into the brain, relatively risk free
• electrical activity is often detected in several areas can be difficult to pinpoint exact region of activity

Question 3

ERP - even related potential

Answer 3

• very small voltage changes in the brain triggered by specific events or stimuli
• target stimulus presented a number of times repeatedly
• neural activity linked to this stimulus will occur consistently
• ERP can be distinguished from general background electrical activity
• temporal resolution, every millisecond
• spacial resolution, only detects activity in superficial areas of the brain
• does not involve inserting electrodes directly into the brain, risk free
• enables the determination of how processing is affected by a specific experimental manipulation

Question 4

PM - post mortem

Answer 4

• used to establish the underlying neurobiology of a behaviour
• person may display dysfunctional behaviour while alive
• when person dies researchers examine brain to look for abnormalities not seen in normal control brains
• temporal resolution, only records permanent changes to brain present after death
• spatial resolution, specific areas of brain changed can be directly observed
• occurs after patient’s death cannot cause harm
• deficit a patient displays during their lifetime may not be linked to the deficit found in the brain