Ways Of Studying The Brain Flashcards
What are the 4 ways of studying the brain?
. Post-mortem examinations
. fMRI (functional magnetic resonance imaging)
. EEG (Electroencephalogram)
. ERP (Event-related potentials)
Why are post-mortem examinations used?
To establish the underlying neurobiology of a particular behaviour by correlating structural abnormalities/damage to behaviour.
Why might researchers examine post-mortem brains?
To match abnormalities with behavioural changes present compared to control individuals with neurotypical (healthy) brains
Who is an early example of post-mortem examinations?
. Broca’s patient Tan
- damage to area of frontal lobe that interfered with speech production to the point that he could only say ‘Tan’, known as expressive aphasia
- locating the area of the brain that seems abnormal allowed researchers to propose the idea that damage to Broca’s area is linked to expressive/Broca’s aphasias
How are post-mortem examinations carried out?
. Brains are precisely cut after a treatment to provide a firmer texture of the brain that is easier to examine
. Unique and unhealthy individuals brains’ are usually what are interested in
What are other uses of post-mortem examinations?
. Establish link between psychiatric disorders and underlying abnormalities in the brain
Eg., Cotter et al (2011) used post-mortem examinations of depressed patients and found that they had a reduced number of glial cells in their frontal cortex
What is spatial resolution in scanning techniques?
The level of accuracy in identifying the exact location of where the brain has its highest activation or in what structure of the brain an abnormality is (how close you can get to the true exact location of the desired site of brain activity)
What is temporal resolution in brain scanning techniques?
The accuracy of identifying the exact location of a brain activity within milliseconds (in a short amount of time)
How were post-mortem examinations helpful as a foundation before scanning techniques?
Allowed hypotheses to be created on the role of the brain in behaviour that can then be tested using scanning techniques
Explain how fMRI works?
Magnetic field and radio waves monitor flow of oxygenated blood to the brain by measuring the change in the energy released by haemoglobin to get a moving picture of the brain as it functions during specific tasks, and compared to baseline levels.
Explain how EEG’s work?
Use electrodes fixed to a participant’s scalp which detects neural activity below where they are placed
- differing numbers of electrodes can be used depending on the focus of the research
Explain how ERP’s work?
Uses same equipment as EEG’s but in response to stimulus introduced by the researcher
What is a post-mortem examination also called?
An autopsy
How is post-mortem examination an invasive way of studying the brain?
The body is ‘invaded’ by devices needed to cut thr brain open
What is the best case study to use as evaluation for the influence of post-mortem examinations?
Paul Barca and his patient Tan
- post-morten examination of Tan in 1861discovered a lesion in the left cerebral hemisphere caused by syphilis
- this led to more knowledge into localisation of function as Broca’s area was named
How have EEG’s been very useful in psychology?
- Helped to identify 5 stages of sleep as it assesses states of arousal and consciousness
- helped to explain why individuals who engage in meditation typically report that it produces a sense of calm peacefulness and relaxation by shedding light on states of consciousness associated with meditation
What research backed up the validity of the idea that meditation produces a sense of calm, showing the influence of EEG’s?
Cahn and Polich (2006) carried out a meta-analysis of studies using EEG during meditation
- findings:
. Various forms of meditation were associated with a reduction in alpha waves and an increase in theta waves. This change indicates increased relaxation with meditation
