Biological Approach SAQ
Brain and behaviour
Discuss one or more techniques used to study the brain in relation to
behaviour + localization of behaviour
Maguire
Localization
Theory - localization is the theory that specific parts of the brain have specific functions that are
related to specific behaviour
- behaviour may involve several different parts of the brain
- specific parts of the brain may have specific functions, they work with other parts of the
brain to create behaviour.
MRI scan
The MRI gives a three-dimensional picture of the brain structures. An MRI scanner uses a
magnetic field and radio waves to map the activity of hydrogen molecules, which are present in
different brain tissue to different degrees. The image can either be viewed as a slice of the brain
from any angle, or it can be used to create a three-dimensional image of the brain.
Aim + Hyp To see whether the brains of London taxi drivers would be somehow different as a result of their
knowledge of the city and hours they spend navigating the streets of London
Procedure Participants: 16 right-handed male London taxi drivers.
1. Taxi drivers were compared with the MRI scans of 50 right-handed males who did not
drive taxi
2. The participants had to completed knowledge test and have their licence for at least 1.5
years
3. Controls were taken from MRI database
4. Sample included a range of ages (so it won’t be confounding)
5. The researchers were looking to see if there was a relationship between the number of
years of driving a taxi and one’s brain anatomy.
6. Singly-blind study, the researcher did not know whether the scan is for driver or control
7. Data from MRI measured using voxel-based morphometry (VBM) -- measure density of
grey matter in the brain. Pixel counting -- counting pixels in the image calculate area of
hippocampus
Results
Two key findings
1. Pixel counting revealed that posterior hippocampus for taxi drivers were significant;y
larger relative to those of control subjects and the anterior hippocampus of taxi drivers
were significantly larger relative to those of control subjects and anterior hippocampus
, were significantly smaller.
2. VBM showed that the volume of the right posterior hippocampus correlated with the
amount of time spent as a taxi driver
3. No differences were observed in other parts of the brain.
Neuroplasticity + formation of neural network + neural pruning
Draganski
Neuroplasticity theory
● neuroplasticity is the brain’s ability to reorganise itself by forming new
neural connections
● allow neurons in the brain to compensate for injury or to respond to
changes in the environment
● every time we learn something new or fire continually from stimulation
in the environment, the neurons sprout new dendrites
● the increase number of synapses available for the behaviour
Neural network formation theory
● the process by which neural networks are formed is called
neuroplasticity
● when a neuron is stimulated, an action potential travels down the axon
● neural networks are created when a neuron or set of neurons are
repeatedly stimulated
● the repeated firing of the neurons, called long term potentiation , results
in gene expression which causes the neurons to sprout new dendrites-
known as dendritic branching
● this increases number of synapses available for the behaviour
● the branching neurons in the brain is called grey matter
Neural pruning theory
● neuroplasticity is the process which our brain adapt to changes in the
environment
● One of the ways that our brains change is through the creation of neural
networks. This happens because of long-term potentiation, the repeated
firing of neurons
● leads to increase in dendritic branching which leads to increase in the
number of synapses
● neural pruning is a decrease in number of synapse as a result of the
removal of dendritic branches
● pruning can be the result of neuron cell death
● the exact mechanisms of neural pruning is not yet fully understood
Aim + hyp to see whether learning a new sill would have an effect on the brains of
Brain and behaviour
Discuss one or more techniques used to study the brain in relation to
behaviour + localization of behaviour
Maguire
Localization
Theory - localization is the theory that specific parts of the brain have specific functions that are
related to specific behaviour
- behaviour may involve several different parts of the brain
- specific parts of the brain may have specific functions, they work with other parts of the
brain to create behaviour.
MRI scan
The MRI gives a three-dimensional picture of the brain structures. An MRI scanner uses a
magnetic field and radio waves to map the activity of hydrogen molecules, which are present in
different brain tissue to different degrees. The image can either be viewed as a slice of the brain
from any angle, or it can be used to create a three-dimensional image of the brain.
Aim + Hyp To see whether the brains of London taxi drivers would be somehow different as a result of their
knowledge of the city and hours they spend navigating the streets of London
Procedure Participants: 16 right-handed male London taxi drivers.
1. Taxi drivers were compared with the MRI scans of 50 right-handed males who did not
drive taxi
2. The participants had to completed knowledge test and have their licence for at least 1.5
years
3. Controls were taken from MRI database
4. Sample included a range of ages (so it won’t be confounding)
5. The researchers were looking to see if there was a relationship between the number of
years of driving a taxi and one’s brain anatomy.
6. Singly-blind study, the researcher did not know whether the scan is for driver or control
7. Data from MRI measured using voxel-based morphometry (VBM) -- measure density of
grey matter in the brain. Pixel counting -- counting pixels in the image calculate area of
hippocampus
Results
Two key findings
1. Pixel counting revealed that posterior hippocampus for taxi drivers were significant;y
larger relative to those of control subjects and the anterior hippocampus of taxi drivers
were significantly larger relative to those of control subjects and anterior hippocampus
, were significantly smaller.
2. VBM showed that the volume of the right posterior hippocampus correlated with the
amount of time spent as a taxi driver
3. No differences were observed in other parts of the brain.
Neuroplasticity + formation of neural network + neural pruning
Draganski
Neuroplasticity theory
● neuroplasticity is the brain’s ability to reorganise itself by forming new
neural connections
● allow neurons in the brain to compensate for injury or to respond to
changes in the environment
● every time we learn something new or fire continually from stimulation
in the environment, the neurons sprout new dendrites
● the increase number of synapses available for the behaviour
Neural network formation theory
● the process by which neural networks are formed is called
neuroplasticity
● when a neuron is stimulated, an action potential travels down the axon
● neural networks are created when a neuron or set of neurons are
repeatedly stimulated
● the repeated firing of the neurons, called long term potentiation , results
in gene expression which causes the neurons to sprout new dendrites-
known as dendritic branching
● this increases number of synapses available for the behaviour
● the branching neurons in the brain is called grey matter
Neural pruning theory
● neuroplasticity is the process which our brain adapt to changes in the
environment
● One of the ways that our brains change is through the creation of neural
networks. This happens because of long-term potentiation, the repeated
firing of neurons
● leads to increase in dendritic branching which leads to increase in the
number of synapses
● neural pruning is a decrease in number of synapse as a result of the
removal of dendritic branches
● pruning can be the result of neuron cell death
● the exact mechanisms of neural pruning is not yet fully understood
Aim + hyp to see whether learning a new sill would have an effect on the brains of
