Brain and behaviour Flashcards
What is localisation?
Localisation of function refers to the fact that different parts of the brain are responsible for specific functions and cognitive processes. The brain is split into 2 hemispheres (left and right) and 4 lobes (temporal, parietal, frontal and occipital). The frontal lobe is responsible for functions such as memory. The occipital is responsible for vision, parietal for functions such as language functions, and higher thinking/sense, and temporal for functions such as hearing and perception. Within the 2 hemispheres, hemispheric lateralisation occurs, in which the left and right side of the brain are specialised to attend to different information. For example, in psychological research, the limbic system is a major focus for its role in memory and emotion, while the hippocampus is responsible for the transfer of short to long term memory.
Genes and behaviour study + RM
Brunner et al - case study
pheromones study + rm
lundstrom and olsen - lab exp
genetic
genetic similarities studies and rm
kendler (twin)/weismann (kinship) - correlation
hormones study + rm
kiecolt and glaser - quasi
HM method
Partial medial temporal lobe resection, removing brain tissue from anterior 2/3 of the hippocampus. Later realising may have destroyed the uncus & amygdala. Used a variety of methods including MRI to explore his deficits post-surgery, and also other methods such lab experiments, interviews, general observation.
HM conclusion
The H.M. Study is evidence for the theory of localization, due to its demonstration that damage to the hippocampus, uncus, and amygdala resulted in total anterograde amnesia and partial retrograde amnesia. Scoville and Milner’s reduction of one’s ability to form and store memories as a function of the limbic system suggests the behaviour as localized to a particular region of the brain. Moreover, Scoville & Milner case study on H.M evidences the localization of short and long-term memory storage as a function of the hippocampus.
HM results
Had anterograde amnesia, losing his ability to form new memories. Post-surgery, couldn’t remember that he had eaten a meal 30 minutes prior, or moving houses. Also been diagnosed with retrograde amnesia, however, his childhood memory was still intact, and intelligence remained above average.
HM aim
HM was an individual who suffered from epileptic seizures, and as a result, underwent a successful experimental surgery which removed 8cm of his brain tissue, including his hippocampus. Milner & Scoville aimed to study his brain in order to gain understanding of the localisation of the hippocampus.
Neuroplasticity K&U
Neuroplasticity refers to the brains ability to change it own structure following changes within the body or external environment. It describes the brain’s tendency to adapt (functionally and physically) due to experience and new learning). The reason for these changes can be genetic (normal pre programmed development of brain) or environmental (e.g. Injury or learning new skills). During infancy, a lot of synapse connections peak with a massive growth by the age of 2-3 years old. When aging, the rarely used connections are deleted, while the frequently used ones are strengthened due to high levels of stimulation or numerous learning opportunities. Long term potentiation refers to the synapses becoming stronger through repeated use, which can then lead to a greater level of response on the post synaptic membrane. Over time, this then leads to neural arborisation, which leads to protein synthesis and gene expression that will be the building blocks used for dendritic branching. Every time we learn something new, those neurons are connected, creating a new trace in the brain called dendritic branching. This consist of the dendrites of the neurons growing in numbers and connecting with other neurons. However, synaptic (neural) pruning may occur when a synapse is not used, or under stimulated. This means that it will go through synaptic pruning, which is the way for the brain to remove synapses that are no longer needed, making functioning of the neural networks more efficient. All of these neurons are part of the a region of the brain referred to as ‘grey matter,’ which home to neural cell bodies, axon terminals, and dendrites, as well as all nerve synapses.
Draganski aim
To see whether learning a new skill - in this case, juggling - would have an effect on the brains of participants.
draganski method
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.
draganski results
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 grey areas had decreased. In the non-juggling sample, there was no change in the brain over the duration of the study in the non-juggling sample.
draganski conclusion
Grey matter grows in brain in response to environmental demands (learning and shrinks in the absence of stimulation (lack of practice). This shows that there is a cause and effect relationship between learning and brain structure.
neural pruning K&U
Neuroplasticity refers to the brains ability to change it own structure following changes within the body or external environment. It describes the brain’s tendency to adapt (functionally and physically) due to experience and new learning), for genetic reasons (e.g. Normal pre-programmed brain development), or environmental (e.g. Injury/learning new skills). During infancy (and by the age of 2-
3 years old), a lot of synapse connections peak with a massive growth. When aging, the rarely used connections are deleted, while the frequently used ones are strengthened due to high levels of stimulation or numerous learning opportunities (neural networks). Long term potentiation refers to the synapses becoming stronger through repeated use, which can then lead to a greater level of response on the post synaptic membrane. Every time we learn something new, those neurons are connected, creating a new trace in the brain called dendritic branching. This consist of the dendrites of the neurons growing in numbers and connecting with other neurons. However, synaptic (neural) pruning may occur when a synapse is not used, or under stimulated, which is the way for the brain to remove synapses that are no longer needed, making functioning of the neural networks more efficient.
neural networks K&U
Neuroplasticity refers to the brains ability to change it own structure following changes within the body or external environment. It describes the brain’s tendency to adapt (functionally and physically) due to experience and new learning), for genetic reasons (e.g. Normal pre-programmed brain development), or environmental (e.g. Injury/learning new skills). This process of learning is possible through the formation of neural networks. These are a series of connected neurons which allow information to travel throughout the body. In the brain, these networks are formed from dendritic branching – dendrites coming together and connecting to form synaptic connections – which occurs when we learn something new. Frequently used synaptic connections, either from frequent stimulation or numerous learning opportunities, are strengthened by a process known as long-term potentiation. This refers to how the synapses becoming stronger through repeated use, which can then lead to a greater level of response on the post synaptic membrane.
add neurotransmitters to beginning of all (agonist/excitatory)
antonova aim
To determine how blocking the acetylcholine receptors with scopolamine affects spatial memory.
antonova method
The participants were 20 healthy male adults, with a mean age of 28. All participants received training about how to use VR set up and rules before partaking in the task. A double-blind procedure was used and participants were randomly allocated to one of two conditions. Group 1 were injected with scopolamine and group 2 with a placebo. Both groups injected with the respective substances 70-90 minutes before taking part in the experimental tasks. Participants were put into a FMRI while playing the “arena task.” This was a complex virtual reality game in which the participants can create spatial memories. There goal was to navigate and reach a pole. After reaching the pole, the screen went blank for 30 seconds. During this time, participants were told to actively rehearse their route to the pole. When the area reappeared, they were at a new starting point, and using their spatial memory, participants were tasked to get back to the pole. Brain activity was measured for 6 trials. Participants returned 3-4 weeks later and redid the test. This time, they received the opposite treatment, meaning if they got placebo the first time, the got scopolamine this time and vice versa. Thus, the study used a repeated measures design.
antonova results
Participants injected with scopolamine showed significant reduction in the activation of the hippocampus when compared to those injected with placebo. It appears that AcH could play a key role in the encoding of spatial memories in humans as well as rats.
antonova conclusion
In conclusion, while there was a higher rate of error in the scopolamine group, it was not a significant difference. Difference in the activity in the hippocampus, however, is significant. This means that the task as designed may not have been the best for showing performance differences; without the use of the fMRI, there would be no way to know
