Psychology Exams > Biological Paper 1 SAQs > Flashcards
Biological Paper 1 SAQs Flashcards
Brain & Behaviour Ethics Study
Rogers & Kesner 2000s
Brain & Behaviour Method Study
Rogers & Kesner 2000s
Techniques used to study the brain Study
Maguire 2000s
Localisation of function Study
Maguire 2000s
Neuroplasticity Study
Maguire 2000s
Neurotransmitters Study
Rogers & Kesner 2000s
Hormones & Behaviour Ethics Study
Meaney 80s
Hormones & Behaviour Method Study
Meaney 80s
Hormones Study
Meaney 80s
Pheromones Study
Wedekind 90s
Genes & Behaviour Ethics Study
Van Oortmerssen & Bakker 80s
Genes & Behaviour Method Study
Van Oortmerssen & Bakker 80s
Genes Study
Gottesman & Shields 90s
Genetic similarity Study
Gottesman & Shields 90s
Evolutionary explanations Study
Wedekind 90s
Rogers & Kesner 2000s Ethical Consideration
Rogers & Kesner 2000s Neurotransmitters
Theory
- Neurotransmission is the transmission of nerve impulses/information between neurons at synapses.
- These nerve impulses are carried out by neurotransmitters (chemical messengers) released by neurons which transmit information/impulses between neurons by binding to receptors on the postsynaptic neuron
- Neurons are brain cells which transmit information
- Synapses are junctions where neurons communicate with one another
- Excitatory neurotransmitters increase the likelihood of postsynaptic neuron firing an action potential AKA receiving and starting a chain of neural of communication
- Inhibitory neurotransmitters decrease the likelihood …
- Agonists are substances which bind and activate receptor sites to amplify the effects of neurotransmitters
- Antagonists are substances which bind but do not activate receptor sites to reduce the effects of neurotransmitters.
Aim
- investigate the role of acetylcholine (excitatory neurotransmitter) in the formation & retrieval of spatial memory
Participants/Research
- 30 rats
Method
- rats acclimated to a maze
- then rats were randomly allocated into 2 groups:
- 1) injected with scopolamine—an antagonist which blocks reception of acetylcholine (expected to help form memories as there is a significant number of acetylcholine receptors in the hippocampus known for memory storage) by binding to postsynaptic neurons and preventing acetylcholine from increasing neural communication about spatial memory
- 2) injection with a placebo saline solution.
- After being injected the rats were repeatedly placed in the maze to locate food, and the number of errors made was measured
Results
- The scopolamine group made more errors thus taking longer to learn the maze—thus deficit in memory formation
Implications
- acetylcholine plays an important role in the formation of spatial memories, as it contributes to neural communication of spatial information
Rogers & Kesner 2000s Methodology
Maguire 2000s Techniques used to study the brain Theory
Theory
- fMRI (functional magnetic resonance imaging)
- brain scanning technique
- images the brain to identify regions which have changed in response to a behaviour
- correlates certain aspects of the brain to certain behaviours
- fMRI observes brain activity by detecting changes in blood flow
Maguire (2000) Localisation of Function
Theory
- localisation of function is the theory that certain parts of the brain correspond to certain functions implicating that the various, specific regions of the brain are responsible for particular human behaviours, emotions, and/or thoughts
Aim
- investigate the role of hippocampus in spatial memory
Participants/Research
- quasi experiment
- taxi drivers from london compared to control group
- all right-handed
Method
- MRI (magnetic resonance imaging) scan of participants brains
- analysed size of hippocampus w/ pixel counting
- & density/volume of w/ hippocampus VBM (voxel-based morphometry)
Results
- larger size & volume of post-interior hippocampus significantly larger correlated with amount of time spent as taxi driver
Implications
- post-interior hippocampus stores spatial information, as it grows to store more spatial information
Maguire 2000s Neuroplasticity
Theory
- Neuroplasticity is ability of brain to undergo plastic changes
- consists of development of neural networks via repetition (long-term potentiation) to increase strength of synaptic connections between neurons (AKA neural pathways) by activating neural pathways consistently
- Neurogenesis the creation of new neurons
- AND neural pruning, the deterioration of synaptic connections of unused neural networks to place resources into growing important, used neural networks
- Neuroplasticity spurs based off responses to environment, thus subject to change over time.
- neural networks grow in the brain through creating and breaking synaptic connections between neurons
Aim
- investigate the brain undergoing plastic changes due to increased navigational requirements
Participants/Research
- quasi experiment
- taxi drivers from london compared to control group
- all right-handed
Method
- MRI (magnetic resonance imaging) scan of participants brains
- analysed size of hippocampus w/ pixel counting
- & density/volume of w/ hippocampus VBM (voxel-based morphometry)
Results
- larger size & volume of post-interior hippocampus significantly larger correlated with amount of time spent as taxi driver suggesting neural growth
- smaller, more shaped anterior-hippocampus of experienced taxi-drivers suggesting neural pruning
Implications
- environmental pressures to learn navigation of London made the brain plastic to increase volume & size of post-interior hippocampus through neurogenesis and long-term potentiation
- as well as possible neural pruning in anterior-hippocampus to defer resources to developing the more important pathways in the post-interior hippocampus
Meaney 80s Ethical Considerations
Meaney 80s Methodology
Meaney 80s Hormones
Theory
- Hormones are chemical messengers released by glands in the endocrine system in the body, and circulate the bloodstream which slowly and gradually affect the body thus behaviour but for longer periods
- hormones have multiple functions and affect a wide range of aspects in the body
- Hormones also indirectly influence behaviour as they act as signals to switch on or off various genes which encode predispositions to behaviour
Aim
- investigate the effect of cortisol on memory
Participants/Research
- true
- Experimental condition: neglected rats (removed from mother, not giving warmth or proper handling)
- Control condition: normally handled rats
Method
- after rats reached maturation they would be repeatedly placed in a stressful situation they had to escape from
- researchers measured the route rats took to escape to determine whether they would escape more effectively as they formed memories of how to escape, and blood samples to measure hormones
Results
- neglected rats secreted more cortisol in response to stressful situation
- took more ineffective routes to escape at older ages due to accelerated hippocampal neuron loss demonstrated in autopsies—due to higher cortisol levels
- elevated cortisol levels without stressful stimulus at older ages
Implications
- prolonged stress of neglected rats caused cortisol levels to increase and remain high, then becoming their baseline without stressful stimulus
- The higher level cortisol caused to hippocampal neuron loss which causes reduced spatial memory abilities
Wedekind 90s Pheromones
Theory
- Pheromones are chemical substances released externally by an individual, for example through scent, which may influence the behaviour of other individuals which encounter the pheromones
Aim
- investigate the relationship between males’ body odour (encoded by MHC genes) as pheromones on female attraction
Participants/Research
- true
Method
- all participants had MHC genes identified
- males wore shirt for 2 days straight to excrete the pheromones on the shirt
- females smelt the males’ shirts/pheromones and ranked the desirability of the odour
Results
- females consistently preferred smell of pheromones with dissimilar MHC genes
Implications
- pheromones released in our scent, determined by genes, may play a role in attracting a genetically diverse mate as different pheromones produce a different desirability for different individuals depending on similarity of MHC genes
Van Oortmerssen & Bakker 80s Ethical Considerations
Wedekind 90s Evolutionary explanations
Theory
- based on assumption of: inheritability of traits, natural selection
- an evolutionary explanation of behaviour could be choosing mates based on genetic diversity to increase the survivability of one’s offspring
- this is evolutionarily advantageous because genetically diverse mates produce more adaptive, & healthy offspring thus better chance of surviving to the next generation & passing on genes
- thus humans which engaged in this behaviour were more likely to have survived and passed on this behaviour to their offspring thus implicating this goal may be an implicit driver of behaviour, as it’s evolutionarily advantageous
Aim
- investigate the role of dissimilar MHC genes expressed as scent in attracting a mate through desirability of scent
- this relates to evolutionary explanations of behaviour because if women implicitly prefer odour produced due to dissimilar MHC genes, then behaviour of attracting a mate may be based on genetic diversity as this is evolutionarily advantageous
Participants/Research
- true
Method
- all participants had MHC genes identified
- males wore shirt for 2 days straight to excrete the odour onto the shirt
- females smelt the males’ shirts and ranked the desirability of the odour
Results
- females consistently preferred smell of pheromones with dissimilar MHC genes
Implications
- the diversity of genes of a potential mate identified through desirability of scent may play a role in attracting a mate, as females preferred odour of dissimilar mates with regard to MHC genes
- attraction to dissimilar genes would increase genetic diversity of offspring to increase survivability and possibility to pass on ones genes, thus implicating an evolutionary factor influencing mate selection
Theory
- an evolutionary explanation of behaviour could be choosing mates based on genetic diversity to increase the survivability of one’s offspring
- this is evolutionarily advantageous become genetically diverse offspring has a better chance of surviving to the next generation and passing on genes
- thus humans which engaged in this behaviour were more likely to have survived and passed on this behaviour to their offspring thus implicating this goal may be an implicit driver of behaviour, as in the past this was evolutionarily advantageous
Van Oortmerssen and Bakker 80s Methodology
Gottesman & Shields 90s Genes
Theory
- Genes, made up of DNA, provide instructions for the structure, and function of the body and behaviour
- The extent to which a gene will result in a particular behaviour depends on: gene expression—whether or not a gene is switched on or off
- gene expression is determined by many things, including hormones which trigger a gene to be expressed/not expressed AKA gene regulation
- Genes may even be permanently switched off through methylation of DNA molecule due to developmental processes when growing up
Aim
- investigate the role of genes and developing schizophrenia
Participants/Research
- field survey
- monozygotic twins
- dizygotic twins (50% shared genes)
Method
- 1 of the twins from each pair already had SZ which they had found from hospital records
- then researchers interviewed other twin W/O SZ & obtained their hospital records to evaluate their likelihood of also developing SZ
Results
- MZ have 48% chance of developing SZ if other twin has SZ
- DZ twins have 17% chance
Implications
- concluded that genetic inheritance plays a role in developing SZ as the higher genetic similarity, the higher chance of developing SZ
Gottesman & Shields 90s Genetic similarity
Theory
- Genes, made up of DNA, provide instructions for the structure, and function of the body and behaviour
- genome refers to all the genes of an individual.
- Genetic similarity refers to the genetic relatedness of two or more individuals. The higher genetic similarity, the higher the relatedness.
Aim
- investigate the role of genetic influences in developing schizophrenia
Participants/Research
- field survey
- monozygotic twins (highest genetic similarity)
- dizygotic twins (50% shared genes)
Method
- 1 of the twins from each pair already had SZ which they had found from hospital records
- then researchers interviewed other twin W/O SZ & obtained their hospital records to evaluate their likelihood of also developing SZ
Results
- Higher genetic similarity - MZ have 48% chance of developing SZ if other twin has SZ
- DZ twins have 17% chance
Implications
- concluded that genetic inheritance plays a role in developing SZ as the higher genetic similarity, the higher chance of developing SZ
