SAQ's BIO The Brain and the Behaviour

Question 1

HM Procedure

Answer 1

• HM had epileptic seizures due to an accident with a bike he had at 7 years old, and underwent a treatment in 1953 that removed a part of his brain at age 27. His hippocampus, amygdala, and the adjacent temporal lobe were removed.
• psychological testing, MRI imaging, interviews with family

Question 1

HM Aim

Answer 1

to better understand the effects that the surgery had had on patient HM.

Question 2

HM Results

Answer 2

• he could not acquire new episodic knowledge (memory of events), or new semantic knowledge (general knowledge about the world). This suggests that the brain structures that were removed from his brain are important for the transfer of information from short-term to long-term memory.
• attacks reduced
• He was able to retain some motor skills exercises, showing the brain stores information in other parts of the brain as well.

Question 3

Maguire Taxi Study Aim

Answer 3

to see whether the brains of London taxi drivers would be somehow different as a result of their exceptional knowledge of the city

Question 4

Maguire Taxi Study Procedure

Answer 4

The brains of 16 right-handed male taxi drivers were MRI scanned and compared with the MRI scans of 50 right-handed males who did not drive taxis (the control group). In order to take part in the study, the participants had to have completed the “Knowledge” test and had their license for at least 1.5 years. The controls were taken from an MRI database. The sample included a range of ages so that age would not be a confounding variable.

Question 5

Maguire Taxi Study Findings

Answer 5

• the volume of the right posterior hippocampi correlated with the amount of time spent as a taxi driver.
• the posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects and the anterior hippocampi were significantly smaller
• No differences were observed in other parts of the brain

Question 6

Rogers and Kesner Aim

Answer 6

to determine the role of acetylcholine in the formation of spatial memory.

Question 7

Rogers and Kesner Procedure

Answer 7

Rogers & Kesner wanted to determine the role of acetylcholine in memory formation and retrieval. They had 30 rats acclimate to a Hebb-Williams maze by placing food in one of the corners. Once the rats were familiar with the maze - and no longer were afraid of the environment - the experiment could begin.

The rats were randomly allocated to one of two conditions. The rats were either injected with scopolamine or with a saline solution ten minutes before running the maze. Scopolamine blocks the acetylcholine receptor sites and thus inhibits any response. The saline solution was a placebo injection. This was done to make sure that the fact of getting an injection alone was not responsible for a change in memory. An injection could result in an increase in adrenaline which would be a confounding variable. The injections were made directly into the hippocampus.

Encoding of memory was assessed by the average number of errors made on the first five trials of Day 1 compared to the last five trials of Day 1, whereas the average number of errors made on the first five trials of Day 2 compared to the last five trials of Day 1 was used to assess retrieval.

Question 8

Rogers and Kesner Findings

Answer 8

The findings were that the scopolamine group took longer and made more mistakes in the learning of the maze - that is, there was a higher average number of mistakes made on the last five trials on Day 1. However, it did not appear to affect the retrieval of memories that had already been created. It appears that acetylcholine may play an important role in the consolidation of spatial memories.

Question 9

Draganski Aim

Answer 9

to see whether learning a new skill - in this case, juggling - would affect the brains of participants.

Question 10

Draganski Procedure

Answer 10

The participants for this study were 24 volunteers between the ages of 20 and 24. There were 21 females and 3 males. All participants were non-jugglers at the start of the study. Each participant had an MRI scan at the start of the study to serve as a base rate for grey matter and brain structure.

Participants were allocated to one of two conditions - the jugglers and the non-jugglers. Those that were in the juggling condition were taught a three-ball cascade juggling routine. They were asked to practice this routine and to notify the researchers when they had mastered it. At that point, the jugglers had a second MRI scan. After the scan, they were told not to juggle anymore and then a third and final scan was carried out three months later. The non-juggling group served as a control group for the duration of the study.

To analyze the MRI scans, the researchers used voxel-based morphometry [VBM] to determine if there were significant differences in neural density (grey matter) in the brains of jugglers vs. non-jugglers.

Question 11

Draganski Findings

Answer 11

From the baseline scans - taken before the study began - they found no significant regional differences in the grey matter between the two conditions. However, at the end of the first part of the study, the jugglers showed a significantly larger amount of grey matter in the mid-temporal area in both hemispheres - an area associated with visual memory. Three months after the participants stopped juggling - when many were no longer able to carry out the routine - the amount of grey matter in these parts of the brain had decreased.

Question 12

Explain one technique used to study the brain in relation to behaviour with reference to one study

Answer 12

“Before the advent of modern technology, psychologists had to rely on studying human behavior through case studies of patients with brain damage or autopsies to understand the brain. In modern times neuro-imaging technology has allowed psychologists to look at a living participant’s brain in a non-invasive way. One such example is the MRI (magnetic resonance imaging), which allows psychologists to look at the structure of the brain. By applying a very strong magnetic field to the brain, the MRI causes the protein spins in hydrogen atoms to align to the magnetic field polarization. Hydrogen is present across the brain as so much of the brain is made of water. A static image is created through a compilation of many different snapshots of the brain. It is possible to create either a 2D slice or a 3D model of the brain. This image indicates the structure of the brain, but it does not provide any indication of function.”

used MRI to understand how HM’s brain functions + changes he underwent

Question 13

Explain localisation of behaviour, with reference to one study

Answer 13

Definition: specific parts of the brain are responsible for specific behaviors.
For example
the hippocampus helps turn short-term memories into long-term memories and the amygdala plays an important role in the fear response.

Question 14

Explain one ethical consideraton in one study of the brain and behaviour

Answer 14

Anonymity - HM
Important: Respecting the ethical principles of research is crucial. Anonymity helps in safeguarding the privacy and confidentiality of participants, which is a fundamental ethical requirement in research.

Question 15

Explain the use of one research method in one study of the brain and the behaviour

Answer 15

Labratory Experiment, Rogers and Kesner

• researchers to establish a causal relationship between two variables - the independent and the dependent variable
• Experiments are based on hypothesis testing - that is, making a measurable and testable hypothesis and then seeing if the results of the study are statistically significant so that they can reject the null hypothesis
• In addition, an experiment must contain at least one group that receives a treatment (the manipulation of an independent variable), and a control group does not receive the treatment. In a true experiment, participants are randomly allocated to conditions.
• highly standardized procedure so the study can be replicated by other researchers -> reliability of results can be further tested
• try to control extraneous variables and randomly allocate participants to conditions, which increases the internal validity, allowing for a cause-and-effect relationship to be established

Question 16

Explain neuroplasticity, with reference to one study

Answer 16

Definition: the brain’s ability to rearrange the connections between its neurons - that is, the changes that occur in the structure of the brain as a result of learning or experience.
- High levels of stimulation and numerous learning opportunities lead to an increase in the density of neural connections.
- This means that the brain of an expert musician should have a thicker area in the cortex related to mastery of music when compared to the brain of a non-musician.
- Every time we learn something new, the neurons connect to create a new trace in the brain.
- This is called dendritic branching because the dendrites of the neurons grow in numbers and connect with other neurons.
- Study shows that the taxi driver have larger hippocampi because of their big amount of knowledge with the city

Question 17

Explain the effect of one neurotransmitter on human behaviour, with reference to one study

Answer 17

Neurotransmission is the process where neurons communicate with other neurons. This is done when the presynaptic neuron releases chemicals called neurotransmitters to cross the gap between two neurons called the synapse. These neurotransmitters then bind to specific receptor sites on the postsynaptic neuron creating an electrical signal called the action potential. If these receptor sites are blocked by another chemical the postsynaptic neuron will not be able to create an action potential, inhibiting the process of neurotransmission. This is a common way of studying the effects of neurotransmission, blocking the receptor sites of a specific neurotransmitter and then noting behavioral changes.

acetylcholine in the formation of spatial memory.

Question 18

Explain the role of one antagonist with reference to one study

Answer 18

An antagonist is any substance that fits into a receptor site on the post-synaptic neuron, inhibiting the neuron. This means that the neuron will not fire, and therefore a behaviour will not happen. An example of an antagonist commonly used in memory research is scopolamine. - Rogers and Kesner

Question 19

Explain the formation of neural networks with the use of one study

Answer 19

The process by which neural networks are formed is called neuroplasticity. When a neuron is stimulated, an action potential (an electrical charge) travels down the axon. Neural networks are created when a neuron or set of neurons are repeatedly stimulated. This repeated firing of neurons, called long-term potentiation, results in gene expression which causes the neurons to sprout new dendrites — known as dendritic branching. This increases the number of synapses available for the behaviour. Dentric branching as a result of stimulation in the environment is seen in a study by Maguire.

• Their brains were larger from the start
  Maguire argued that this demonstrates the plasticity of the hippocampus in response to environmental demands. She argued that the posterior hippocampus stores a spatial representation of the environment and that in the London taxi drivers, the volume of the posterior hippocampus expanded because of their high reliance on navigation skills and spatial memories. By repeatedly firing the neurons required to remember the spatial layout of the City of London, the number of synapses was increased, creating a general neural network.

Question 20

Explain neural pruning/neural plasticity with reference to one study

Answer 20

• When you learn something new, your neural networks will extend
• When you stop learning, the brain will prune
• This shows that when learning a new skill, new neural networks were created. However, when the behaviour stopped and those neurons were no longer activated, the neurons were pruned. Researchers hypothesize that neural pruning is a way to increase the efficiency of the brain.

Question 21

Explain the role of one agonist with reference to one study

Answer 21

Neurotransmission is the process where neurons communicate with other neurons. This is done when the presynaptic neuron releases chemicals called neurotransmitters to cross the gap between two neurons called the synapse. These neurotransmitters then bind to specific receptor sites on the postsynaptic neuron, creating an electrical signal called the action potential. If these receptor sites are blocked by another chemical, the postsynaptic neuron will not be able to create an action potential, inhibiting the process of neurotransmission. This is a common way of studying the effects of neurotransmission, blocking the receptor sites of a specific neurotransmitter and then noting behavioural changes.
An agonist is any chemical that binds to a receptor site on a post-synaptic neuron, causing the neuron to fire. Neurotransmitters are endogenous agonist — the brains natural chemical that bind to receptor sits, leading to an action potential. Acetylcholine (endogenous agnoist)

Question 22

Explain the role of inhibitory or excitatory synapses in one behaviour with reference to one study

Answer 22

Neurotransmitters play an important role in human behaviour. They are released from the terminal buttons of a neuron and then travel across a synapse where they attach to receptor sites on the postsynaptic membrane.
Some neurotransmitters are seen as more excitatory — that is, they make the target neuron more likely to “fire” an action potential. A neurotransmitter can sometimes have either an excitatory or an inhibitory effect, depending on the receptor sites that it binds to. One example of how a neurotransmitter binds to excitatory receptor sites is the role of acetylcholine in the formation of spatial memories.

Question 23

Maguire Taxi Study Conclusion

Answer 23

this demonstrates that the hippocampus may change in response to environmental demands. The study also shows that the posterior hippocampus is involved when previously learned spatial information is used as it was larger in the taxi drivers, whereas the anterior hippocampal region may be more involved during the encoding of new environmental layouts as it was larger in the non taxi drivers.