Biological Approach Flashcards
Brain Imaging Techniques
MRI is a brain imaging technique that uses magnetic fields and radio waves
It produces detailed images of the brain’s structure
MRI can detect abnormalities such as tumors, bleeding, and nerve injury
It can also show changes in brain structure due to learning or environment
The person lies inside a tube-like machine during the scan and must remain still
MRI is safe and non-invasive, and does not expose the person to ionizing radiation
Psychologists use MRIs to study the relationship between the brain and behaviour
Study: Maguire et al (2000)
Aim: To examine whether structural changes could be detected in the brain of people with extensive experience of spatial navigation
Method: Structural MRI scans were obtained. 16 right-handed male London taxi drivers participated; all had been driving for more than 1.5 years. Scans of 50 healthy right-handed males who did not drive taxis were included for comparison. The mean age did not differ between the two groups.
Results: Increased grey matter was found in the brains of taxi drivers compared with members of the control group in the right and left hippocampi. The increased volume was found in the posterior hippocampus.
Conclusion: The results provide evidence for structural differences between the hippocampi of London taxi drivers and control participants, therefore suggesting that extensive practice with spatial navigation affects the hippocampus. This demonstrates that the brain can change in response to environmental demands.
Localisation
The theory of localisation of function suggests that specific cognitive functions are mediated by specific brain regions
The brain is made up of distinct areas responsible for specific functions, such as language, memory, and movement
This is backed by evidence from brain injury studies that have found that damage to the Broca’s area in the frontal lobe can cause damage to language- whilst damage to the hippocampus can reduce memory ability
The theory has been further researched by psychologists using MRIs
Study: Maguire et al (2000)
Aim: To examine whether structural changes could be detected in the brain of people with extensive experience of spatial navigation
Method: Structural MRI scans were obtained. 16 right-handed male London taxi drivers participated; all had been driving for more than 1.5 years. Scans of 50 healthy right-handed males who did not drive taxis were included for comparison. The mean age did not differ between the two groups.
Results: Increased grey matter was found in the brains of taxi drivers compared with members of the control group in the right and left hippocampi. The increased volume was found in the posterior hippocampus.
Conclusion: The results provide evidence for structural differences between the hippocampi of London taxi drivers and control participants, therefore suggesting that extensive practice with spatial navigation affects the hippocampus. This demonstrates that the brain can change in response to environmental demands.
Neuroplasticity
Neuroplasticity is the ability of the brain to reorganize itself and form new connections throughout life
It allows the brain to adapt to new situations and learn new things
Neuroplasticity is the result of changes in the strength of connections between neurons or the creation of new neurones
It can be influenced by various factors, including experience, learning, and environment.
This has been researched by researchers such as Draganski
Draganski et al (2004)
Aim: To investigate whether structural changes in the brain would occur in response to practicing a simple juggling routine.
Method: Experiment, mixed design.
Procedure: The sample was randomly divided into two groups: jugglers and non-jugglers. Jugglers spent three months learning a classic juggling routine with three balls followed by three months in which they were instructed to stop practicing. Participants in the control group never practices juggling. Three MRIs were performed on both groups- one before the start of the experiment, one after 3 months, one after 6 months.
Results: There were no differences in brain structure between jugglers and non-jugglers before the experiment. After 3 months, the jugglers had significantly more grey matter in the mid-temporal area of the cortex. These areas are known to be responsible for coordination of movement. After 6 months, the differences had decreased- however the jugglers still had more grey matter than in the first scan.
Conclusion: Grey matter grows in the brain in response to environmental demands, and shrinks in the absence of stimulation. This shows that there is a cause-and-effect relationship between learning and brain structure.
Neurotransmitters (excitatory)
Neurotransmitters are chemical messengers that are used to pass messages between neurons
An example of an excitatory NT is acetylcholine (ACH)
It has an important role in many cognitive processes such as learning, attention, cognition, and memory.
It is endogenous, meaning it originates in the body.
As it is an excitatory neurotransmitter- it has stimulating effects on the brain by increasing the likelihood of a neurone firing.
Antonova et al (2011)
Aim: To see how participants could create spatial memories whilst playing a VR game after being injected with scopolamine (an antagonist which has adverse effects on acetylcholine) or a placebo.
Procedure: The researchers used a sample of 20 healthy male adults. The study was a double-blind procedure.
Method: They were put into an fMRI where they were scanned whilst playing the “Arena task”, where participants navigate around an area with the goal of reaching a pole. After finding the pole, the screen would go blank for 30 seconds and when the area reappeared the participant was then at a different location, from which they had to navigate back to the pole. Before their behavior was observed, the participants were trained on how to play the game. The study lasted 6 trials, and participants returned a few weeks later and redid the test but they received the opposite treatment to the original study.
Findings: It was found that when participants were injected with scopolamine they demonstrated a big reduction in the activation of the hippocampus than when they were injected with the placebo.
Conclusion: Scopolamine has a significant effect on one’s spatial memory ability- because of the way it reduced levels of acetylcholine.
Hormones
The endocrine system is a system of ductless glands that secrete hormones into the blood. Their role is to regulate bodily functions.
Hormones are chemical messengers that are secreted into the blood and are transported to specific target organs / tissues - where there are target receptors.
An example of a hormone is cortisol. It is associated with processes such as metabolism, and the immune system as well as many cognitive processes.
Psychologists theorise that it can have adverse effects on cognitive functions such as memory.
Newcomer et al (1999)
Aim: To determine whether cortisol has adverse effects on cognitive functions- such as memory
Method: Three groups of participants were given tablets that contained different amounts of cortisol. Group 1 consumed a tablet that contained 100mg of cortisol (a high amount- expected to be seen in the blood of someone in a major stress event). The second group took a tablet containing 40mg of cortisol (a low amount- expected to be seen in the blood of someone in a minor stress event). The last group took a placebo tablet. This was the control group. All participants were asked to listen to and then recall parts of a passage, to test their verbal declarative memory.
Findings: Newcomer et al found that high levels of the stress hormone, cortisol, interferes with verbal declarative memory- for example the group that took 100mg performed the work.
Conclusion: They decided that it does in fact have adverse effects on a persons verbal declarative memory.
Phermonones
Unlike hormones, which act inside of the body, pheromones act outside of the body, at species level.
They are sometimes referred to as exogenous hormones.
Most species of mammals produce them and there is evidence that humans do too- which pheromones supposedly playing a role in human behaviour such as mating behaviour or mother-baby bonding behaviour.
However none of these studies have been conclusive. One study that took place in order to investigate the effects of pheromones on behaviour was a study conducted by Zhou et al.
Zhou et al (2014)
Aim: to investigate the effects of the pheromones AND and EST- two pheromones that are associated with human attraction and perception.
Method: There were 4 groups of participants. Hetero men, hetero women, homo men, homo women. These groups viewed a walking human shape knows as ‘point light marker’. The gender of the human shape was ambiguous. Participants had to say whether they thought the human shape was male or female. At the same time, participants were made smell either a male pheremone (AND) or a female pheremone (EST).
Results: Zhou et al. found that participants responded to the pheromones of the gender that they were attracted to, and perceived the ‘point light marker’ respectively- for example, straight women and gay men smelled AND and perceived the point light marker as a man.
Conclusion: Zhou et al. concluded that human pheromones do exist and they have an effect on human behaviour- perhaps alerting people of possible mating opportunities.
Genes
Genetic information is contained in chromosomes. Each human has 23 pairs of chromosomes.
Genes contain biological instructions to form protein molecules from amino acids.
Psychologists have taken an interest in how genetics may affect behaviour, because of the fact that genetics affect so many other aspects of our life.
One study that investigates genes, and specifically their effects on behaviour, is a study by Caspi et al
Caspi et al (2003)
Aim: To investigate the role of the 5HTT gene in developing depression in réponse to stressful life events
Method: It was a longitudinal field study with 1037 children. Participants were divided into three groups (two short alleles, one short one long allele, both long alleles). They were assessed longitudinally between ages 3 and 26. A ‘life history calendar’ was used to assess stressful life events and an interview to asses symptoms of depression.
Results: Participants who had one or two short alleles reacted to stressful life events with more symptoms of depression. FOr example, participants who had a major stressful life event at age 21 tended to develop depression by 26 if they carried a short allele of 5HTT
Conclusion: 5HTT gene is responsible for modulating an individuals vulnerability to stress
Genetic Similarity
Psycholgists theorize that genetics play a large role in determining the way we act, and our overall psychological characteristics. For example, whether we suffer from Major Depressive Disorder or not.
In order to investigate these theories, they use kinship studies to compare the behaviours of family members and their psychological similarities.
One kinship study that investigates genes, is a twin study that investigates twins and the way their twinship investigates whether or not they suffer from depression.
It is a study conducted by McGuffin et al (1996).
McGuffin et al (1996)
Aim: To estimate the contribution of genes and shared family environment to the tendency of having major depressive disorder, and to examine the influence of characteristics of one twin suffering from the disorder on the likelihood of the other also suffering.
Method: 177 sets of same sex twins in which at least 1 twin suffered from MDD from the Maudsley Hospital Register were used for this study. Diagnostic assessments and interviews were carried out on 69 of the original twins and 75 co twins. The researcher was blind to whether a twin was MZ or DZ- (one twin was interviewed by one researcher and the other was interviewed by another).
Results: The study found that the concordance rate of mdd for MZ twins was 46% and for DZ it was 20%.
Conclusion: This shows that there is a habitability factor for mdd. McGuffin concluded that there is a strong genetic component to the likeliness of suffering from major depressive disorder.
Evolution
Evolution is the process by which plants and animals develop by descent, with modification, from earlier existing forms. These changes happen at the genetic level as organisms’ genes change and combine in different ways through reproduction and are passed down the generations.
A lot of psychologists believe in the idea of heritability- which is the theory that our personality and behaviour are partly inherited, for example mate selection and mating behaviour.
Scientists believe that inherently, females choose mates for their ability to support children, and males inherently choose mates for their ability to have children.
A study that investigates this is a study by Clarke & Hatfield.
Clarke and Hatfield (1978 & 1982)
This study conducted by Clarke and Hatfield took place in 1989, and aimed to investigate the differences in choosiness shown by males and females when approached by a stranger offering sex.
The study was carried out in two different years- 1978 and 1982. Both dates involved using an opportunity sample of 48 female and 48 male Florida Uni students.
5 female and 4 male confederates hung around the campus and had to approach lone members of the opposite sex, who they found attractive, and explain that they find the student attractive and then ask either if they wanted to go out that night, or come over tonight, or go to bed with them tonight.
Clarke and Hatfield found that the request for a date was met with around 50% agreement from both men and women. The request to go to the confederates apartment produced agreement of 69% from men, but 0-6% from women. The request for sex was met by the agreement of 69%-75% of the men, but 0& of the women.
They concluded that women do seem to have increased choosiness when it comes to their sexual behaviour, whereas men seem to be less bothered by a possibly risky sexual encounter.
This links to the evolutionary theory that men are less picky because of their inherent need to find as many mates as possible and produce offspring.
GLO: RM used to study brain and behavior
One research method used to study brain and behaviour with a biological approach is a lab experiment.
Lab experiments allow the investigator to control the environment to determine if a change in the IV causes a change in the DV.
In order to be confident that a cause and effect relationship does exist, all other variables are controlled as best as possible. These outside variables are called extraneous variables. A
n example of a lab experiment which explores the relationship between brain and behaviour is a study conducted by Draganski et al.
Draganski et al (2004)
Aim: To investigate whether structural changes in the brain would occur in response to practicing a simple juggling routine.
Method: Experiment, mixed design.
Procedure: The sample was randomly divided into two groups: jugglers and non-jugglers. Jugglers spent three months learning a classic juggling routine with three balls followed by three months in which they were instructed to stop practicing. Participants in the control group never practices juggling. Three MRIs were performed on both groups- one before the start of the experiment, one after 3 months, one after 6 months.
Results: There were no differences in brain structure between jugglers and non-jugglers before the experiment. After 3 months, the jugglers had significantly more grey matter in the mid-temporal area of the cortex. These areas are known to be responsible for coordination of movement. After 6 months, the differences had decreased- however the jugglers still had more grey matter than in the first scan.
Conclusion: Grey matter grows in the brain in response to environmental demands, and shrinks in the absence of stimulation. This shows that there is a cause-and-effect relationship between learning and brain structure.
GLO: EC used in the study of brain and behavior
One ethical consideration that is relevant to a study into brain and behavior is Informed Consent.
It is important that researchers receive informed consent from participants to ensure that the experiment is ethical.
Informed consent involves ensuring that participants are willing to take part and have their results used / published by a researcher.
One of example of a study in which informed consent was used was a study conducted by Draganski et al.
Draganski et al (2004):
Aim: To investigate whether structural changes in the brain would occur in response to practicing a simple juggling routine.
Method: Experiment, mixed design.
Procedure: The sample was randomly divided into two groups: jugglers and non-jugglers. Jugglers spent three months learning a classic juggling routine with three balls followed by three months in which they were instructed to stop practicing. Participants in the control group never practices juggling. Three MRIs were performed on both groups- one before the start of the experiment, one after 3 months, one after 6 months.
Results: There were no differences in brain structure between jugglers and non-jugglers before the experiment. After 3 months, the jugglers had significantly more grey matter in the mid-temporal area of the cortex. These areas are known to be responsible for coordination of movement. After 6 months, the differences had decreased- however the jugglers still had more grey matter than in the first scan.
Conclusion: Grey matter grows in the brain in response to environmental demands, and shrinks in the absence of stimulation. This shows that there is a cause-and-effect relationship between learning and brain structure.
GLO: RM used to study hormones/pheromones
The research method used in one study investigating the effect of hormones on behaviour is a lab experiment.
Lab experiments allow the investigator to control the environment to determine if a change in the IV causes a change in the DV.
In order to be confident that a cause and effect relationship does exist, all other variables are controlled as best as possible. These outside variables are called extraneous variables.
An example of a lab experiment which was used to investigate hormones and behaviour is a study conducted by Newcomer et al.
Newcomer et al (1999):
Aim: To determine whether cortisol has adverse effects on cognitive functions- such as memory
Method: Three groups of participants were given tablets that contained different amounts of cortisol. Group 1 consumed a tablet that contained 100mg of cortisol (a high amount- expected to be seen in the blood of someone in a major stress event). The second group took a tablet containing 40mg of cortisol (a low amount- expected to be seen in the blood of someone in a minor stress event). The last group took a placebo tablet. This was the control group. All participants were asked to listen to and then recall parts of a passage, to test their verbal declarative memory.
Findings: Newcomer et al found that high levels of the stress hormone, cortisol, interferes with verbal declarative memory- for example the group that took 100mg performed the work.
Conclusion: They decided that it does in fact have adverse effects on a persons verbal declarative memory.
GLO: EC used in the study of hormones/pheromones
One ethical consideration that is relevant to a study about hormones and behaviour is protection from harm.
Protection from harm ensures that participants in experiments don’t leave the experiment in a worse mental state to how they joined.
For example, in a study conducted by Newcomer et al, certain participants were given high levels of cortisol that in turn caused them high levels of stress.
If participants had pre-existing mental instability, making them endure high levels of stress for the study could lead to them leading in a worse psychological state to how they joined the study.
Newcomer et al (1999):
Aim: To determine whether cortisol has adverse effects on cognitive functions- such as memory
Method: Three groups of participants were given tablets that contained different amounts of cortisol. Group 1 consumed a tablet that contained 100mg of cortisol (a high amount- expected to be seen in the blood of someone in a major stress event). The second group took a tablet containing 40mg of cortisol (a low amount- expected to be seen in the blood of someone in a minor stress event). The last group took a placebo tablet. This was the control group. All participants were asked to listen to and then recall parts of a passage, to test their verbal declarative memory.
Findings: Newcomer et al found that high levels of the stress hormone, cortisol, interferes with verbal declarative memory- for example the group that took 100mg performed the work.
Conclusion: They decided that it does in fact have adverse effects on a persons verbal declarative memory.
GLO: RM used to study genetics and behaviour
One research method relevant to one study using a biological approach to understanding genetics and behaviour is a Quasi-experiment.
Quasi experiments often take place in natural conditions, however in quasi experiments, participants are not randomly allocated to groups because the groups already exist, for example, gender, age, ethnicity, sexuality.
The researcher does not always have full control over the IV since it is naturally occurring, and therefore it is harder to prove causation in quasi experiments.
An example of a quasi experiment to study the relationship between genes and behaviour is a study conducted by Caspi et al.
Caspi et al (2003):
Aim: To investigate the role of the 5HTT gene in developing depression in réponse to stressful life events
Method: It was a longitudinal field study with 1037 children. Participants were divided into three groups (two short alleles, one short one long allele, both long alleles). They were assessed longitudinally between ages 3 and 26. A ‘life history calendar’ was used to assess stressful life events and an interview to asses symptoms of depression.
Results: Participants who had one or two short alleles reacted to stressful life events with more symptoms of depression. FOr example, participants who had a major stressful life event at age 21 tended to develop depression by 26 if they carried a short allele of 5HTT
Conclusion: 5HTT gene is responsible for modulating an individuals vulnerability to stress
GLO: EC used in the study of genetics and behaviour
One ethical consideration that is relevant to a study into understanding genetics and behaviour is confidentiality.
Confidentiality is important for this, as studies into genetics reveal information that is sensitive- e.g in the study conducted by Caspi et al, it was found whether participants had two short alleles or not- indicating whether or not they had more depressive symptoms.
In this case, it is important that these results were kept confidential, because knowing whether someone has two short alleles or not has negative implications.
Caspi et al (2003):
Aim: To investigate the role of the 5HTT gene in developing depression in réponse to stressful life events
Method: It was a longitudinal field study with 1037 children. Participants were divided into three groups (two short alleles, one short one long allele, both long alleles). They were assessed longitudinally between ages 3 and 26. A ‘life history calendar’ was used to assess stressful life events and an interview to asses symptoms of depression.
Results: Participants who had one or two short alleles reacted to stressful life events with more symptoms of depression. FOr example, participants who had a major stressful life event at age 21 tended to develop depression by 26 if they carried a short allele of 5HTT
Conclusion: 5HTT gene is responsible for modulating an individuals vulnerability to stress
