ways of studying the brain

Question 1

Ways of studing brain

Answer 1

fMRI
ERP
EEG
Post Mortom

Question 2

fMRI

Answer 2

FUNCTIONAL MAGNETIC RESONANCE IMAGING

Measures blood flow in the brain when a person performs a task.

Neurons in the brain that are most active use the most energy.
Energy requires glucose and oxygen.

Oxygen is released for use by these active neurons at which point the haemoglobin (which carries the oxygen) becomes deoxygenated
Deoxygenated haemoglobin has a different magnetic quality from oxygenated haemoglobin.
An fMRI can detect these different magnetic qualities to create a dynamic 3d map of the brain.
Temporal resolution: fMRI images show activity approx. 1-4 seconds after it occurs.
Spatial resolution: fMRI images are thought to be accurate within 1-2mm

Question 3

EEG

Answer 3

ELECTROENCEPHALOGRAM (EEG)

• Measure electrical activity through electrodes attached to the scalp.
• Info is processed in the brain as electrical activity in the form of action potentials or nerve impulses.
• Small electrical charges are detected by the electrodes and graphed over a period, indicating the level of activity
  o 4 types of EEG patterns: alpha, beta, theta and delta waves
• How to detect which pattern it is
• Amplitude= intensity or size of the activity.
• Frequency= the speed or quantity of activity.
• Alpha waves- associated with light and sleep
• Theta and Delta waves are associated with deeper sleep
• EEG can be used to detect illnesses like epilepsy and sleep disorders

Question 4

ERP

Answer 4

EVENT RELATED POTENTIALS (ERP)

• Are similar equipment to EEG (Electrodes attached to the scalp.)
• Stimulus (picture/sound) is presented to a participant and the researcher looks for activity related to that stimulus.
• The stimulus is presented many times and an average response is graphed.
• Latency= the time interval between the presentation of the stimulus and the response

Question 5

Post mortem

Answer 5

• Researchers study the physical brain of a person who displayed a particular behaviour while they were alive.
• BROCA patient had lesion in the area of the brain which, he inferred, is important for speech production.
• Iverson examined the brains of deceased schizophrenic patients.
  Found higher concentration of dopamine (especially in the limbic system) compared to non-schizophrenic patients

Question 6

fMRI eval

Answer 6

Str: non invasive and doesnt expose brain to harmful radiation

Lim: overlooks the networked nature of brain activity
focuses on localised activity
Communication is most critical to brain function

Question 7

EEG eval

Answer 7

Str: provides a recording in real time rather than a still image
= accurately mesaure a particular task

Lim: Can only look superficially- cannot reveal what happens deeper in the brain eg hypothalamus
Too invasive for alive humans

Question 8

ERP eval

Answer 8

Str: Determine response to a particular stimulus

Lim: Small and difficult to pick out from other electrical activity in the brain- require a large number of trials to gather meaningful data
= limits on types of questions ERPs can acc answer

Question 9

PM eval

Answer 9

Str: More detailed examination= Application- Sz
Understanding origins of Sz w structural abnormalities of brain and changes in neurotransmitter systems

Lim: Factors: way they die, length of time between death and pm, drug treatments, age of death

Retrosepctive- cant follow up on research