Transcript Technology in brain research

Technology in
brain research
Brain-imaging technologies
Invasive techniques
• Instead of invasive techniques such as ablation
(removing) and lesioning (scarring), which
raise serious ethical concerns due to:
• damage cannot be reversed
• Causing pain
• Potential harm unknown
• One can use…
Brain Scanning Techniques
• EEG (electroencephalogram)
• PET (positron emission topography)
• FMRI (functional magnetic resonance imaging)
EEG (electroencephalogram)
• The EEG registers patterns of voltage change in
the brain
• Help the researchers in the Study of sleep,
emotions and epilepsy
• Weaknesses are:
1. provide only limited information
2. cannot reveal what is happening in the deeper
brain regions
3. Cannot show the actual functioning of the brain
PET (positron emission topography)
• Monitors glucose metabolism in the brain (using
up energy)
• The patient is injected with a harmless dose of
radioactive glucose
• The scans produce coloured maps of brain
activity
• Used to: diagnose abnormalities like tumours,
Alzheimer’s, schizophrenia, compare sex
differences
• Greatest advantage is: can record ongoing activity
in the brain, such as thinking
FMRI (functional magnetic resonance
imaging)
• Provides three-dimensional pictures of the
brain structures, using magnetic fields and
radio waves
• Shows actual brain activity
• Higher resolution than PET scans and easier to
carry out
• The most frequently used today
Evaluation of brain scans
• Weakness: not a natural environment, low ecological
validity
• The use of colours may exaggerate the different activities of
the brain
• Brain activates for various reasons – parts can be “lighted”
but not necessarily used in the response
• …“we know that it is not possible to definitively determine
whether a person is anxious or feeling connected simply by
looking at activity in a particular brain region.”
• …“a one-to-one mapping between a brain region and a
mental state is not possible.” Michael Shermer © 2008 SCIENTIFIC
AMERICAN
Section A markbands
SAQ app. 250 words/20 min
Marks Level descriptor
• 0
The answer does not reach a standard described by the descriptors below.
• 1 to 3
There is an attempt to answer the question, but knowledge and
understanding is limited, often inaccurate, or of marginal relevance to the
question.
• 4 to 6
The question is partially answered. Knowledge and understanding is accurate
but limited. Either the command term is not effectively addressed or the
response is not sufficiently explicit in answering the question.
• 7 to 8
The question is answered in a focused and effective manner and meets the
demands of the command term. The response is supported by appropriate
and accurate knowledge and understanding of research.
Command terms with definitions handout
Three parts-test on Thursday
Be ready on Thursday to answer two SAQs from
this chapter (will be graded):
1. The effect of cognition on physiology
2. The localization of function of the brain
Could be asked to explain or examine and to
know a study as reference
3. A multiple choice test on the whole chapter