Biological SAQ Questions Flashcards
Explain one technique used to study the brain in relation to behaviour with reference to one study.
Neuro-imaging technology – MRI (magnetic resonance imaging) allowed psychologists to look at the structure of the brain.
- By applying a strong magnetic force to the brain, it causes the protein spins in hydrogen atoms to align to the magnetic field polarisation. - Hydrogen is present across the brain as so much of the brain is made of water. - Through a compilation of multiple images of the brain, a static image is created - Possible to create 2D or 3D imaging - Indication of the structure of the brain – not necessarily the functions
Maguire:
- Study conducted used an MRI scan to look at neural plasticity and localisation of function in the brain - looked at MRI scans of right-handed male taxi drivers who had been driving for at least 1.5 years, compared to right-handed males who were not taxi drivers
(Results)
- found that the taxi drivers had larger posterior hippocampi than non-taxi drivers, but that they also had smaller anterior hippocampi - The MRI scan showed that only certain areas of the brain were impacted by being a taxi driver thus supporting the theory of localisation of function - postulated that the posterior hippocampus must play role in spatial memory - found through voxel-based morphology which measures the volume of the brain from the MRI scans that more grey matter in the hippocampus correlated with the number of years as a taxi driver thus supporting the theory of neuroplasticity, as the brain appeared to change as a response to external stimuli.
Maguire’s study shows how imaging techniques such as the MRI can be used to study the brain. the MRI allowed Maguire to look at this structure of the participants’ brains.
Explain localisation of function or behaviour, with reference to one study.
The theory of localisation refers to the idea that different parts of the brain are responsible for specific behaviours, or that certain functions are localised to certain areas in the brain.
Maguire:
Explain neuroplasticity with reference to one study.
Brain plasticity refers to 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. 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 neurones grow in numbers and connect with other neurones.
Maguire:
- Study conducted used an MRI scan to look at neural plasticity - looked at MRI scans of right-handed male taxi drivers who had been driving for at least 1.5 years, compared to right-handed males who were not taxi drivers - found that the taxi drivers had larger posterior hippocampi than non-taxi drivers, but that they also had smaller anterior hippocampi - found through voxel-based morphology which measures the volume of the brain from the MRI scans that more grey matter in the hippocampus correlated with the number of years as a taxi driver thus supporting the theory of neuroplasticity, as the brain appeared to change as a response to external stimuli.
Maguire argues that this demonstrates that the hippocampus may change in response to environmental demands. Maguire’s study showed that repeated use of the hippocampus in taxi drivers lead to changes in the brain - or neuroplasticity
Explain the effect of one neurotransmitter on human behaviour, with reference to one study.
One effect of one neurotransmitter on a behaviour is the effect of acetylcholine on memory.
-Acetylcholine seems to play a role in the encoding of spatial memories.
Antonova:
- Double-blind study: the participant group was made up only of males - Participants injected with either scopolamine – a drug that blocks acetylcholine receptor sites or a placebo - They were then asked to play a virtual reality game in which they had to remember how to get to a certain place in the game. Once they found where the “pole” was that they were looking for, they would be “put” at a new starting point and asked to find the pole again. - They were in an fMRI while carrying out the task so that brain activity could be observed.
(Results)
- The researchers found that when the participants were injected with scopolamine, they took longer to find the “pole” than did the group that received the placebo. - fMRI showed more activity in the hippocampus in the placebo group than in the scopolamine group.
The hippocampus is where STM is transferred to long-term memory; it is also where there are many acetylcholine receptor sites in the brain. This study seems to show that acetylcholine plays a key role in the encoding of spatial memory.
Explain one ethical consideration in one study of the brain and behaviour.
One ethical consideration in the biological approach is informed consent.
- Informed consent means that before someone agrees to participate in a study, the researcher must explain the purpose and procedure of the study. - In addition, the researcher must explain the person’s rights––including the right to withdraw and that all data will be kept anonymous. - Any potential negative effects of participation must be explained.
The biological approach has some special problems with regard to informed consent. First, the biological approach uses animals which cannot actually give consent. In addition, biological researchers often do studies of people who have mental illness or brain damage. It could be argued that these participants may not be able to understand what they are agreeing to. Finally, often biological research is rather complex and may not be understood by the average person, making “informed consent” difficult.
HM by Milner:
- HM had severe amnesia as a result of an operation which was done to stop epileptic seizures - HM had both retrograde amnesia (he couldn’t remember what happened before the operation) and he had anterograde amnesia (he couldn’t create new memories) - Milner carried out a case study and found that the hippocampus plays a key role in the transfer of episodic and semantic memories from short-term to long-term memory. - As HM could not remember giving consent, this study is ethically problematic. - HM was asked to give consent throughout the experiment, but it is not clear that he really understood what was happening or who Milner actually was. - Originally consent was given by HM’s mother and then later by his caretakers. - HM may not have been able to take advantage of his right to withdraw either because he did not understand or he forgot.
Informed consent is important so that researchers do not take advantage of participants. Many of the types of participants used in biological research make obtaining informed consent difficult.
Explain the use of one research method in one study of the brain and behaviour.
One research method used in the study of the brain and behaviour is a quasi-experiment design.
- A quasi-experiment is designed a lot like a true experiment except that in the quasi-experimental design, the participants are not randomly assigned to experimental groups. - Quasi-experiments are employed when the researcher is interested in independent variables that cannot be randomly assigned. Usually this happens when the independent variable in question is something that is an innate characteristic of the participants involved.
Maguire:
- London drivers have to spend years memorising the streets of London, as such, the aim of the study was to see whether the brains of London taxi drivers would be somehow different as a result of their exceptional knowledge of the city and the many hours that they spend behind the wheel navigating the streets of London. - Quasi-experiment design was used as researchers were looking to see if there was a relationship between the number of years of driving a taxi and the anatomy of one's brain. - Study conducted used an MRI scan to look at neural plasticity and localisation of function in the brain - looked at MRI scans of right-handed male taxi drivers who had been driving for at least 1.5 years, compared to right-handed males who were not taxi drivers - found that the taxi drivers had larger posterior hippocampi than non-taxi drivers, but that they also had smaller anterior hippocampi
As the researchers wanted to find correlation between brain changes in taxi-drivers compared to the control, the independent variable, taxi-drivers (IV) could not be manipulated, thus a quasi-experiment study had to be used. From the use of a quasi-experiment, the researchers could find a correlation between being a taxi-driver and posterior hippocampi size.
Explain the role of one antagonist with reference to one study.
An antagonist is any substance that fits into a receptor site on the post-synaptic neuron, inhibiting the neuron. This means that the neurone will not fire and therefore a behaviour will not happen.
- Acetylcholine is a neurotransmitter that plays a role in the formation of memories. It is not possible for researchers to directly observe the role of neurotransmitters, so one of the ways that they attempt to understand the role of different neurotransmitters is by giving animals or human participants an antagonist. - They want to see what happens when acetylcholine receptors are blocked and the neurones are "not allowed" to fire. - Participants injected with either scopolamine – a drug that blocks acetylcholine receptor sites or a placebo - They were then asked to play a virtual reality game in which they had to remember how to get to a certain place in the game. Once they found where the “pole” was that they were looking for, they would be “put” at a new starting point and asked to find the pole again. - They were in an fMRI while carrying out the task so that brain activity could be observed.
(Results)
- The researchers found that when the participants were injected with scopolamine, they took longer to find the “pole” than did the group that received the placebo. - fMRI showed more activity in the hippocampus in the placebo group than in the scopolamine group.
By using an antagonist, blocking AcH receptor sites, researchers are better able to understand the role of the neurotransmitter in the formation of memory.
Explain the formation of neural networks with the use of one study.
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 the 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. The branching of neurons in the brain is called grey matter. Dendritic branching as a result of stimulation in the environment is seen in….
Maguire:
- Study conducted used an MRI scan to look at neural plasticity - looked at MRI scans of right-handed male taxi drivers who had been driving for at least 1.5 years, compared to right-handed males who were not taxi drivers - found that the taxi drivers had larger posterior hippocampi than non-taxi drivers, but that they also had smaller anterior hippocampi - found through voxel-based morphology which measures the volume of the brain from the MRI scans that more grey matter in the hippocampus correlated with the number of years as a taxi driver
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 greater neural network.
Explain neural pruning, with reference to one study.
Draganski
Explain the role of one agonist with reference to one study.
Antonova
Explain the role of inhibitory or excitatory synapses in one behaviour with reference to one study.
Antonova
Explain the effect of one hormone on human behaviour with reference to one study.
McGaugh & Cahill
Explain one effect of one potential pheromone in human behaviour with reference to one study.
Zhou
Explain the use of one research method in one study of hormones or pheromones
McGaugh & Cahill
Explain the role of one gene in one behaviour with reference to one study.
Caspi et al
