Discuss the use of brain imaging technologies in
investigating the relationships between biological
factors and behaviour.
Introduction
State what you are doing in the essay
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This essay will attempt to offer a balanced review of the use of brain imaging technologies in investigating the
relationships between biological factors and behaviour
State the different types of brain imaging technologies used at the BLA
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PET: Positron Emission Topography
MRI: Magnetic Resonance Imaging
fMRI: functional Magnetic Resonance Imaging
EEG: Electroencephalogram
CAT: Computerised Axial Tomography
Each method has its own advantages and disadvantages and are appropriate in varying situations
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Explain why Brain imaging technologies are used at the BLA
Brain imaging technologies are methods used in psychology to examine the human brain.
They are particularly useful in neuropsychology
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As it provides an opportunity to study the active brain
Allows researchers to see where specific brain processes take place
Enables researchers to study localisation of function (specific areas of the brain are responsible for different
functions) in a living human brain
It also provides correlations between brain activity and behaviour – though it does not necessarily detail a
cause-effect relationship.
State the brain imaging technology being discussed
o In the following essay, the brain imaging technologies that will be discussed are MRI and PET scans, which will
be investigated in terms of its role in investigating the correlations/relationships between biological factors and
behaviour.
Body
Biological Factor 1: Neuroplasticity; Brain Damage Brain Imaging Technology 1: MRI Scans
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Introduce the physiological process of neuroplasticity
The first brain imaging technology, MRI scans, will be firstly investigated in its relation to the biological process
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of neuroplasticity.
Describe the MRI brain imaging technology
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This technique uses magnetic fields and radio waves to produce 3D computer-generated images.
MRI scans involve people to remove all metal objects and clothing where they lie within an MRI machine.
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It can distinguish among different types of soft tissue and allows researchers to see structures within the brain.
Supporting Study: Maguire et al. (2000)
Introduce StudyConnection of study to question:
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An example of a study which utilizes MRI scans to investigate the relationships between biological factors and
behaviour is a study conducted by Maguire et al. (2000).
Aim:
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Maguire hypothesised that full licensed taxi drivers in London would have a different hippocampi structure in their
brains compared to “normal? people.
Methods:
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This was based on the knowledge that London taxi drivers must do a two-year training course where they end up
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being able to find their way around the city without a map.
MRI scans were used to scan the structure of their hippocampi, which were compared to already existing MRI scans
of healthy males who did not drive taxis.
Results:
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Taxi drivers? left and right hippocampi had a larger volume compared to the non-taxi drivers.
Some parts of the hippocampi were smaller in the taxi drivers.
Conclusions:
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Maguire concluded that there was probably a redistribution of grey matter in the hippocampi of taxi drivers due to
the regular use of the spatial memory skills required to remember roads; the neurons are stronger in areas of the
brain which are used most.
Connection of study to question
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By using an MRI, Maguire was able to observe the structures in the brain and find a correlation between
environmental enrichment on neuroplasticity, a physiological process occurring in the brain, particularly around the
hippocampi region which then affects behaviour in terms of memory.
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Maguire used MRI scans to investigate the structure of the hippocampi, which would not be able to be seen using
other technologies such as an EEG or a PET scan.
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Biological Factor: Brains areas, hippocampi
Behaviour: Remembering, Memory
Supporting Study 2: HM - Milner and Scoville (1957)
Introduce StudyConnection of study to question:
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Another study which utilizes MRI scans to investigate a physiological process is a study conducted by Milner and
Scoville (1957).
Background:
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HM suffered epileptic seizures after a head injury at age 9
Doctors performed surgery to stop seizures
Tissue from temporal lobe, and hippocampus was removed
HM suffered anterograde amnesia
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He could recall information from early life but could not form new memories
HM was studied using an MRI in 1997
Findings:
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The brain scan showed that there was damage to the hippocampus, amygdala, and areas close to the
hippocampus
Connection of study to question
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By using MRI scanning technology, researchers were able to investigate the effects of biological factors on
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behaviour and make a correlation between certain brain areas and memory and other behaviour.
MRI scans were used to see the structures of the brain to determine the extent of brain damage
The structures would not be able to be clearly seen using other technologies such as EEGs or CTs.
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Biological Factor 2: Localization of Function/Brain Damage Brain Imaging Technology 2:
PET Scans
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Introduce the cognitive process of language
The next biological factor which will be discussed with the brain imaging technology of PET Scans are brain
interactions and functions.
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Describe PET brain imaging technology
PET scans require patients to be injected with a radioactive glucose tracer which shows the areas where glucose
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is absorbed in the active brain.
More glucose metabolism means more brain activity.
PET scans show a coloured visual display of brain activity; where radioactive tracer is absorbed
 Red indicates areas with the most activity
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Blue indicates areas with the least activity
Supporting Study 3: Tierney et al (2001)
Introduce Study --> Connection of study to question:
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An example of a study which utilizes PET scans to investigate the result of brain damage is a study conducted by
Tierney et al. (2001).
Aim:
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To evaluate, using PET scans, the bilingual language compensation following early childhood brain damage
Background:
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37 year old man (known as MA) with normal speech functions who was participating in a normal speech study
It was discovered that he had a lesion in his left frontal lobe
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Probably as a result of encephalitis he suffered at the age of 6 weeks
He had no significant long-term, clinically consequences
Both his parents were deaf and he used sign language at home from a very young age.
Researchers were curious to know if this might have had something to do with his ability to speak despite the brain
damage (that should have prevented him from doing so.
Methods:
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Researchers compared MA to 12 control participants, who were fluent in sign language
PET scanning technologies were used while the participants produced narrative speech or signs
Results:
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MA's right hemisphere was more active than the controls' during the production of both speech and sign
language
Conclusion:
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Language function seems to have developed in the right hemisphere instead of the left hemisphere as an
adaptation following his early brain damage
Connection of study to outcome
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Tierney utilised PET scans to investigate the biological factors in MA and observe the areas of the brain (LOF) linked
to language and language acquisition.
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The ongoing activity in the brain would not be able to be seen using other technologies such as EEGs or MRIs.
Biological Factor: Damage to brain, specific areas
Behaviour: Language, language acquisition
Supporting Study 4: Raine et al. (1997)
Introduce StudyConnection of study to question:
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Another study which uses PET scans to investigate the result of brain damage on behaviour/personality is a wellknown study conducted by Raine et al. (1997).
Aims:
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The aim of the experiment was to discover (using PET scans) if murderers who pleaded not guilty by reason of
insanity (NGRI) show evidence of brain abnormalities.
Methods:
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41 participants (39 male, 2 female) NGRI’s (average age of 34.3)
41 participants (controls), selected based on sex, age and matched to a NGRI participant
Each participant was injected with a glucose tracer (bonds to glucose) (for PET scans)
o Glucose tracers tracks brain activity as the brain absorbs glucose (as energy)
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Radioactive glucose tracer emits positively charged particles called positrons, which are picked up by the scan
PET scans show colourful maps of brain activity; red = most active, blue = least active.
They had to perform tasks requiring them to detect target signals for 32 minutes
Results:
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NGRIs had less activity in the pre-frontal cortex
Linked to self-control and emotion
NGRIs had lower activity in the amygdala and medial temporal hippocampus
o Lack of inhibition of violent behaviour
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Fearlessness - Inappropriate emotional expression
Failure to learn consequences for violence
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Connection of study to outcome
Raine utilised PET scan technology to investigate relationships between biological factor in criminals (NGRI’s) and
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their behaviour.
Through Raine’s study, which involved PET scans, psychologists were able to determine a link between the
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amygdala (biological factor) and crime (behaviour).
Biological factor: damage to specific brain areas
Behaviour attributed/linked to: Criminal/unlawful acts
o Lack of inhibition of violent behaviour
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Fearlessness – inappropriate emotional expression
Failure to learn consequences for violence
Aggressive behaviour
Conclusion
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What is the significance of using brain scans? Answer the question
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In conclusion, brain imaging technologies are very useful in determining the relationship between biological
factors and behaviour
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Useful in different situations.
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All these methods have their own advantages and disadvantages, primarily involving invasiveness and levels of
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radioactivity.
However, all of these methods contribute to investigating the relationship between biological factors and
behaviour.