The Biological Approach

Question 1

Brain Scanning Techniques: Structural imaging; MRI scans

Answer 1

An MRI scanner uses magnetic field and radio waves to map the activity of hydrogen molecules, which are present in different brain tissue to different degrees.

The image can either be viewed as a slice of the brain from any angle, or it can be used to create a three-dimensional image of the brain

The human body is mostly water. Water molecules contain hydrogen protons, which become aligned in a magnetic field. An MRI scanner applies a strong magnetic field which aligns the proton ‘spins’.

The scanner also produces a radio frequency current that creates a varying magnetic field. The protons absorb the energy from the magnetic field and flip their spins. When the field is turned off, the protons gradually return to their normal spin, a process called precession. The return process produces a radio signal that can be measured by receivers in the scanners and made into an image.

The MRI is a composite image of several images of the brain.

Question 2

MRI scans: Holistic evaluation

Answer 2

Strengths:

• it is non-invasive, with minimal potential harm to the participant
• the image has a high spatial resolution; this gives the researchers a good sense of the actual structure of the brain.

Weaknesses:

• the MRI only indicates structure; it doesn’t actually map what is happening in the brain
• MRI research is correlational in research, not allowing researchers to establish a clear cause and effect relationship

Question 3

Maguire et al. APFC (brain scanning techniques/ localisation of brain function/ neuroplasticity)

Answer 3

Aim:
The aim of the study was to investigate whether the brains of London taxi drivers would exhibit structural differences as a result of their extensive spatial navigation experience and exceptional knowledge of the city’s layout.

Procedure:
Sixteen right-handed male London taxi drivers, who had been licensed for at least 1.5 years and completed the “Knowledge” test, were compared with 50 right-handed male non-taxi drivers from an MRI database. The study used voxel-based morphometry (VBM) to measure grey matter density and pixel counting to assess the area of the hippocampus in MRI scans. This was a single-blind study, meaning the researcher analyzing the MRI data did not know whether the scan belonged to a taxi driver or a control participant.

Findings:

1. Pixel Counting: Taxi drivers had significantly larger posterior hippocampi and smaller anterior hippocampi compared to controls.
2. VBM: There was a positive correlation between the volume of the right posterior hippocampi and the number of years spent as a taxi driver. No significant differences were found in other brain regions.

Conclusion:
The study concluded that the hippocampus may undergo structural changes in response to the demands of spatial navigation. The posterior hippocampus appears to be involved in utilizing previously learned spatial information, while the anterior hippocampus may be more engaged in encoding new environmental layouts.

Question 4

Maguire et al. evaluation (brain scanning techniques)

Answer 4

Evaluation:

• Strengths:
  
  • The use of MRI scans allows for precise measurement of brain structure.
  • The single-blind design reduces researcher bias.
  • The study controls for age as a confounding variable.
• Limitations:
  
  • As a quasi-experiment, it cannot establish a cause-and-effect relationship.
  • The sample is gender-biased, limiting generalizability.
  • Some may argue that individuals with naturally larger hippocampi might be more inclined to become taxi drivers, although this is countered by the correlation with driving experience

Question 5

Maguire et al ethics

Answer 5

• • The study is ethically sound; MRI scanning is non-invasive, and participants gave informed consent.
  • The study maintained high standards of ethical research practices.

Question 6

Maguire et al: Link paragraph for use of MRI to investigate human behaviour

Answer 6

This study illustrates the utility of MRI technology in exploring the relationship between environmental demands and brain structure. MRI provides high-resolution images of the brain, enabling researchers to measure grey matter density and specific brain regions’ volumes, such as the hippocampus, with great accuracy. Through techniques like voxel-based morphometry and pixel counting, researchers can identify correlations between brain anatomy and behavioral variables, such as the extensive navigation experience of taxi drivers in this study. By revealing structural changes in the brain associated with specific experiences, MRI technology contributes significantly to our understanding of brain plasticity and the localization of function in human behavior.

Question 7

Localisation of brain function theory outline

Answer 7

Localisation of brain function refers to the theory that different parts of the brain are responsible for different aspects of human functioning, such as behaviours

This relates directly to the assumption of the biological approach that conditions, emotions and behaviours are products of the anatomy and physiology of our nervous and endocrine systems

Psychologists investigating localisation of brain function from the biological approach use brain-imaging techniques, brain surgeries and brain autopsies to investigate the correlation between brain processes and structures and human behaviour.

Question 8

Draganski et al. (localisation of brain function/ neuroplasticity)

Answer 8

Aim

The aim of the study was to investigate whether learning a new skill, specifically juggling, would have an impact on the brain structure of the participants.

Procedure

1. Participants: 24 volunteers aged 20-24 (21 females, 3 males), all non-jugglers at the start.
2. Baseline MRI: All participants underwent an initial MRI scan to measure grey matter and brain structure.
3. Condition Assignment: Participants were divided into two groups - jugglers and non-jugglers (control group).
4. Juggling Training: The juggling group learned a three-ball cascade routine and practiced until mastery. Upon mastering, they had a second MRI scan.
5. Post-Juggling Phase: After the second scan, jugglers were instructed to stop juggling. A third MRI scan was conducted three months later.
6. Control Group: The non-jugglers did not learn juggling and served as a control group throughout the study.

Findings

• Baseline Comparison: Initial MRI scans showed no significant differences in grey matter between jugglers and non-jugglers.
• Post-Learning: After mastering juggling, jugglers exhibited a significant increase in grey matter in the mid-temporal area of both hemispheres, linked to visual memory.
• After Cessation: Three months after stopping juggling, the jugglers showed a decrease in grey matter in the same brain regions.
• Control Group: There were no changes in grey matter in the control group throughout the study.

Conclusion

Learning to juggle led to an increase in grey matter in the mid-temporal areas of the brain, suggesting that juggling primarily enhances visual memory areas rather than procedural memory regions like the cerebellum or basal ganglia. This increase in grey matter diminished after participants stopped practicing juggling. The study demonstrates the brain’s plasticity in response to acquiring new skills and the reversibility of these changes upon discontinuation of the activity.

Question 9

Draganski et al evaluation (localisation of brain function/ neuroplasticity)

Answer 9

Strengths

1. Clear Aim and Focus: The study has a specific aim to investigate structural brain changes resulting from learning a new skill, making the research question straightforward and focused.
2. Controlled Design: By including a control group of non-jugglers, the study effectively controls for variables that might otherwise influence changes in grey matter, such as age or environment, helping to isolate the effects of learning to juggle.
3. Longitudinal Approach: The study not only measured changes immediately after learning but also after a three-month cessation period, allowing researchers to observe both the increase and potential reversal of grey matter changes, which highlights the plasticity and adaptability of the brain.
4. Objective Measures: MRI scans provide objective, quantifiable data on grey matter volume, which enhances the study’s validity and reduces potential biases associated with self-reported data.

Limitations

1. Small Sample Size: With only 24 participants, the study’s sample size is relatively small. This may limit the generalizability of the findings, as small sample sizes increase the risk of sampling error.
2. Gender Imbalance: The participant group is predominantly female (21 females, 3 males), which may affect the results if there are gender-specific differences in neuroplasticity or grey matter response to learning.
3. Limited Skill and Practice Time Control: While participants practiced juggling until they mastered the skill, variations in time taken to achieve mastery or differences in individual practice routines could introduce variability in the results. Additionally, the study does not specify whether other factors (like sleep or lifestyle) were monitored, which could also influence grey matter changes.
4. Absence of Other Neuroanatomical Regions: The study found changes in grey matter in the mid-temporal areas related to visual memory but did not observe changes in other areas associated with motor skills (e.g., cerebellum or basal ganglia). However, more extensive regions may be involved in complex motor tasks, and limiting the study to grey matter alone may overlook other relevant changes.

Implications and Future Research Directions

1. Skill-Based Neuroplasticity: This study supports the idea that learning new skills, even briefly, can lead to structural changes in the brain. Future research could investigate whether other complex skills, such as learning a musical instrument or language, result in similar patterns of grey matter increase and reduction post-cessation.
2. Long-Term Effects of Continuous Practice: While the study looked at grey matter changes three months after cessation, it would be insightful to examine the effects of continuous, long-term juggling practice to see if these structural changes stabilize or further increase.
3. Diversity in Participants: Including a larger, more balanced sample size and controlling for potential confounding variables, such as participants’ physical activity or lifestyle, would strengthen the study’s applicability to a broader population.
4. Exploration of Other Brain Regions and Techniques: Including scans or analysis techniques that measure changes in other brain areas, such as white matter or regions directly linked to motor skills, could yield a more comprehensive understanding of how learning juggling—or similar skills—affects the brain.

Question 10

Maguire et al link paragraph (localisation of brain function)

Answer 10

Link to Localisation of Brain Function

This study’s findings contribute to the understanding of brain function localization by highlighting how specific brain regions adapt structurally in response to skill learning. The increase in grey matter in the mid-temporal regions, associated with visual memory, supports the idea that certain brain areas specialize in specific types of processing—in this case, visual and spatial memory needed for juggling. The absence of structural changes in other regions, such as the cerebellum or basal ganglia (areas traditionally associated with procedural memory and motor coordination), suggests that mastering juggling engages visual memory and perception more than motor skills, reinforcing the theory of functional localization. This insight aligns with previous research showing that distinct brain regions are responsible for particular cognitive functions, and it demonstrates how localized brain plasticity can occur in response to targeted learning experiences.

Question 11

Maguire localisation of brain function link paragraph

Answer 11

This study provides insight into the localization of brain function, specifically within the hippocampus. The findings suggest that different regions of the hippocampus have distinct roles: the posterior hippocampus is involved in retrieving and using previously learned spatial information, while the anterior hippocampus may be more crucial for encoding new spatial information. This distinction aligns with the theory of localized brain functions, where specific brain areas are responsible for particular cognitive processes. By demonstrating structural differences in the hippocampi of taxi drivers, who rely heavily on spatial navigation skills, the study underscores how environmental demands can shape and potentially localize brain function.

Question 12

Localisation of brain function holistic evaluation

Answer 12

Localisation research is often limited to very specific behaviours.

Most of the research is of two types; animal research, where there can be a direct manipulation of the IV. Or correlational research, such as many of the quasi experiments that are done. The correlational nature of the research may lead to drawing indirect conclusions.

Question 13

Neuroplasticity (neural networks and synaptic pruning)

Answer 13

Neuroplasticity is the term used to describe the changes in neural pathways and synapses due to changes in behaviour, environment, thinking, emotions, as well as changing from bodily injury.

• It is fundamentally the ability of the brain to change through the making and breaking of synaptic connections between neurons. It occurs on different scales from synaptic plasticity to cortical remapping
• Synaptic plasticity is neuroplasticity occurring on the level of a separate neuron, construction of new synaptic connections (neural networks) and elimination of the ones that are not used (synaptic pruning)
• Cortical remapping is when neurons remap to new areas of the brain

Neuroplasticity is the brain’s ability to reorganise itself by forming new neural connections. It allows neurons in the brain to compensate for injury or to respond to changes in the environment.

Neural networks

• The process by which neural networks are formed is called neuroplasticity. This is known as synaptic plasticity
• When a neuron is stimulated, an action potential 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

Synaptic pruning

Another way that our brain can change is through synaptic pruning- which is a decrease in the number of synapses as a result of removing dendritic branches

Synaptic pruning refers to the process by which extra neurons and synaptic connections are eliminated in order to increase the efficiency of neuronal transmissions

Synaptic pruning is a natural process that occurs in the brain between early childhood and adulthood. During synaptic pruning, the brain eliminates extra synapses. Synaptic pruning is our body’s way of maintaining more efficient brain function as we get older and learn new complex information.

• pruning can be the result of neuronal cell death, hormones such as cortisol or the lack of use of a neural pathway
• The exact mechanism of synaptic pruning is not yet fully understood.

Question 14

Draganski link to neural networks

Answer 14

Link to Neural Networks

This study underscores the role of neural networks in skill acquisition by showing that learning juggling engages specific regions within the brain’s network of interconnected neurons. The increase in grey matter within the mid-temporal area suggests that neural networks in this region strengthen and adapt in response to the visual and spatial demands of juggling. By stimulating connections that support visual memory, learning to juggle appears to enhance the efficiency and density of neural pathways involved in processing movement and spatial information, reflecting the brain’s ability to reorganize and reinforce networks based on experience.

Question 15

Draganski et al link to synaptic pruning

Answer 15

Link to Synaptic Pruning

The findings also relate to synaptic pruning, the process by which unused neural connections are reduced to increase efficiency in the brain. The decrease in grey matter observed three months after participants stopped juggling suggests that, once a skill is no longer practiced, the brain may prune or reduce the synaptic density in regions previously adapted for that skill. This pruning helps the brain allocate resources to more active networks, illustrating how experience-dependent changes in the brain can be reversible and emphasizing the importance of continued practice to maintain structural changes.

Question 16

Draganski link to neuroplasiticity

Answer 16

Link to Synaptic Plasticity

This study provides insight into synaptic plasticity, the brain’s ability to form and strengthen synaptic connections in response to learning and experience. The observed increase in grey matter within the mid-temporal regions after learning juggling reflects synaptic plasticity, where repeated practice strengthens synaptic connections within areas involved in visual memory and spatial processing. The reduction in grey matter after participants ceased juggling further highlights the dynamic nature of synaptic plasticity, showing that synaptic strength and density can diminish when a skill is no longer in use, demonstrating the brain’s adaptability to changing behavioral demands.

Question 17

Maguire link to neuroplasticity

Answer 17

This study illustrates the concept of neuroplasticity, the brain’s ability to reorganize itself by forming new neural connections in response to learning or environmental demands. The significant structural differences observed in the hippocampi of taxi drivers, specifically the enlargement of the posterior hippocampus and the reduction in the size of the anterior hippocampus, suggest that the brain can adapt to the cognitive demands of navigating complex environments. This adaptation is further supported by the positive correlation between the volume of the right posterior hippocampus and the number of years spent driving a taxi. These findings highlight how prolonged engagement in a specific cognitive activity, such as spatial navigation, can lead to measurable changes in brain structure, thereby demonstrating the brain’s capacity for neuroplasticity.

Question 18

Neuroplasticity Holistic Evaluation

Answer 18

An application of the knowledge that neuroplasticity takes place as the brain changes in response to disorders like depression and anxiety is to look at ways in which these changes could be interrupted, and maybe even reversed, in an effort to heal the brain and therefore decrease symptoms.

• Neuroplasticity can be observed at multiple scales, from microscopic changes in individual neurons, to larger-scale changes such as cortical remapping in response to injury.
• The behaviour of the brain cannot however be observed live
• Research is generally correlational in nature
• Some research is also prospective in nature which allows the researcher to observe changes over time; However, these studies are often low in internal validity as it is not possible to control for extraneous variables.
• Animal research tends to be more highly controlled, but this is difficult to generalise to humans. Although the physiological processes are the same, there are differences in the level of cognitive complexity between people and animals.

Question 19

Neurotransmitters theory outline

Answer 19

The Neuron is the basic unit in the nervous system. It is a specialised cell that receives and transmits electrochemical nerve impulses. Over three-quarters of all Neurons are found in the brain and there are three main types:

1. sensory carrying information from the sense organs to the central nervous systems
2. Motor carrying information from the central nervous system to the muscles and glands
3. Relay- the most numerous and they connect neurons to other neurons and coordinate the activities of motor and sensory neurons

Neurotransmitters are chemicals that carry the electrical impulses between neurones in the brain and body. They act within the synapse.

Neurotransmitters are released from the terminal buttons. They fit into receptor sites on the post-synaptic membrane. Some stay in the synapse and many are eventually re-uptaken by the original neuron.

Synaptic Transmission

Action potential from presynaptic neuron stimulates fusion of vesicles with neurotransmitters to presynaptic membrane. Chemical neurotransmitters diffuse across the synaptic cleft and are detected by receptors in the postsynaptic neuron

Summation; the neurotransmitters are excited and increase the electric potential in the postsynaptic neuron. So that a threshold for new action potential forms

The chemical neurotransmitters are reabsorbed and placed into vesicles.

Question 20

Excitatory and inhibitory neurotransmission

Answer 20

Neurotransmission can either be excitatory or inhibitory- they can either instruct the receiving neuron to fire or not to fire. The effect of a synapse is determined by its neurotransmitter content and the properties of the receptors present in the postsynaptic membrane.

It is the action of the particular neurotransmitter in the terminal button which makes a synapse either excitatory or inhibitory.

• Excitatory neurotransmitters: Increase the likelihood of a neuron firing. excitatory neurotransmitters include acetylcholine
• Inhibitory neurotransmitters: Decrease the likelihood of a neuron firing. Inhibitory neurotransmitters include GABA

Acetylcholine is usually excitatory but can be inhibitory depending on the neuron receptor site; serotonin is both excitatory and inhibitory.

It is important to understand how neurotransmitters work in order to understand drug treatments. Drugs can replicate the shape of the neurotransmitter and then occupy the receptor site on the dendrites

Sometimes, the neurotransmitter or drug may be excitatory- that is, they activate the neuron- like stepping on a gas pedal. Sometimes the neurotransmitter or drug may be inhibitory- that is, it prevents a neuron from firing.

Question 21

Antonova et al. APFC (neurotransmitters)

Answer 21

Antagonist (use of scoplolamine)

Agonist (Acetylcholine)

Excitatory (Acetylcholine)

Aim

The aim of this study was to investigate the role of acetylcholine in the encoding of spatial memories in humans by examining the effects of scopolamine, an acetylcholine receptor antagonist, on hippocampal activation during a spatial memory task.

Participants

The study involved a sample of twenty healthy male adults with a mean age of 28 years. The participants were randomly allocated to either the scopolamine or placebo condition in a double-blind, repeated measures design.

Method

The participants were injected with either scopolamine or a placebo 70-90 minutes before performing the experimental task. The task involved playing the “Arena task,” a virtual reality game designed to assess spatial memory. Participants had to navigate to a pole in the arena, with a blank screen interval during which they rehearsed the pole’s location before starting from a new point in the arena. Brain activity was measured using fMRI across six trials. Participants underwent training to ensure they were familiar with the game controls and rules. They returned 3-4 weeks later to perform the test again, receiving the opposite treatment from the initial session.

Findings

The study found that scopolamine significantly reduced hippocampal activation compared to the placebo. This suggests that acetylcholine is critical for encoding spatial memories. Despite the higher error rate in the scopolamine group, it was not significantly different from the placebo group, indicating that the fMRI was crucial in detecting the biological differences in hippocampal activity.

Conclusions

The study concluded that acetylcholine plays a key role in the encoding of spatial memories in humans, similar to findings in animal studies. The significant reduction in hippocampal activation under scopolamine indicates that acetylcholine is essential for effective spatial memory encoding.

Question 22

Antonova et al evaluation

Answer 22

The repeated measures design minimised participant variability, and the counter-balancing controlled for practice effects. The double-blind procedure reduced researcher bias. However, some participants reported stress from the unfamiliar drug injection or the fMRI environment, which could impact hippocampal function. The small sample size necessitates replication to confirm reliability.

Question 23

Antonova link to neurotransmitters effects on human behaviour

Answer 23

This study highlights the critical role neurotransmitters play in human behavior, specifically in memory and learning. Acetylcholine, an important neurotransmitter involved in attention and memory, was shown to be essential for spatial memory encoding in the hippocampus. The reduction in hippocampal activation with scopolamine administration demonstrates how manipulating neurotransmitter systems can directly affect cognitive functions. This aligns with broader research indicating that neurotransmitters influence a range of behaviors and cognitive processes, including learning, memory, and attention. Understanding these mechanisms can provide insights into neuropsychiatric conditions and guide the development of targeted treatments.

Question 24

Porges et al. APFC

Answer 24

Aim

This study aimed to examine the relationship between GABA concentrations in the frontal and posterior midline cerebral regions and cognitive function in older adults, specifically assessing if higher GABA levels correlate with better cognitive performance and whether GABA declines with age.

Participants and Method

The study involved 94 healthy older adults (mean age 73). GABA concentrations were measured using MEGA-PRESS 1H-MRS, and cognitive performance was assessed via the Montreal Cognitive Assessment (MoCA). Age, education, and brain atrophy were controlled for in the analysis.

Findings

Higher frontal GABA concentrations were linked to better cognitive performance, even after accounting for age and other factors. Additionally, GABA levels in both the frontal and posterior regions declined with age, indicating that GABA changes may contribute to cognitive aging.

Conclusion

The study suggests that cognitive function in older adults is influenced by GABA concentrations in the frontal cortex, with age-related declines in GABA potentially underlying cognitive aging. Proton MRS is highlighted as a valuable tool for studying neurochemical influences on age-related cognitive changes.

Question 25

Porges et al evaluation

Answer 25

• Highly standardised procedure; and standardised way to test levels of GABA
• Can be used to create medications for dementia; and to treat cognitive decline
• Study is purely correlational as the researcher cannot alter neurotransmitter levels
• Aim to look at older people so it is fairly generalisable

Question 26

Porges et al. link to neurotransmitters role on behaviour

Answer 26

This study underscores the critical role of neurotransmitters, specifically GABA, in regulating cognitive function and behavior. GABA is the principal inhibitory neurotransmitter in the brain, essential for maintaining neuronal excitability and preventing overstimulation. The decline in GABA concentrations with age, as demonstrated in this study, highlights a potential mechanism for age-related cognitive decline. This aligns with broader research on neurotransmitters, which shows that they are pivotal in modulating various aspects of human behavior, including mood, attention, and perception. The ability of GABA to influence cognitive performance in older adults reinforces the importance of maintaining neurotransmitter balance for optimal brain function and suggests potential avenues for therapeutic interventions aimed at mitigating cognitive decline through modulation of neurotransmitter systems.

Question 27

Neurotransmitters holistic evaluation

Answer 27

Holistic evaluation:

• Much of the research on humans is correlational in nature. This means that we cannot establish a cause-and-effect relationship. For example, in the case of depression, bidirectional ambiguity is a problem. We do not know if a deficit of dopamine and serotonin causes depression or whether these deficits are a result of depression.
• The argument that neurotransmitters are the cause of behaviour is reductionist. Although a reductionist argument may be good in the study of memory since such arguments could potentially lead to positive strategies for helping people with memory impairment, explaining a complex behaviour like falling in love as a “neurochemical cocktail” could be considered an over simplification of human behaviour.
• Research on neurotransmission can only be done indirectly.
• Reliance on fMRI technology means that the limitations of such techniques are relevant to the evaluation of many studies of neurotransmission.
• One of the key strengths of neurotransmission theories is that they have led to successful treatments for certain behaviours. Successful drug treatments have been developed for psychological disorders.
• There is experimental research that supports the role of neurotransmitters in behaviour.
  These experiments can be replicated to establish reliability.
  However, many of these studies are on animals. This means that we cannot guarantee that the neurotransmitter plays the same role in human behaviour.

Useful applications

• The findings from research into neurotransmitters could have a useful application for those with Alzheimer’s disease as drugs which block Acetylcholine in the brain could be used to decrease the amount of acetylcholine during sleep so aid memory consolidation.
  Neurotransmitters are made up of amino acids from the food we eat, and knowing this can encourage a healthy diet high in amino acids, although be aware that not all of these find their way into the brain across the blood-brain barrier. However some do, and an understanding of the links between diet and mental as well as physical health is improving every day.

Future direction

• More and more research is exploring interactions between genes, neurotransmission, environment and behaviour to give us a holistic picture of brain functions and correlations between all of these factors and human behaviour.

Question 28

Hormones theory outline

Answer 28

The endocrine system

• Works alongside the CNS to control vital functions in the body using the sympathetic/ parasympathetic nervous system
• The endocrine system differs from the nervous system in that its chemical signals are slower-moving and longer-lasting
• The nervous system regulates relatively rapid processes, whereas hormones regulate long-term ongoing processes, such as growth, metabolism, digestion and reproduction
• CNS and endocrine systems are interdependent- they interact and influence each other.
• Hormones and glands help the endocrine system to do its job
• Some chemicals can be both hormones and neurotransmitters (e.g. adrenaline)

Glands and Hormones

• Glands produce hormones
• Hormones act as chemical messengers within the body, telling it to perform specific physical and mental functions by travelling through the bloodstream
• Most hormones affect cells in several organs throughout the body leading to powerful responses
• Hormones do not cause behaviour, rather they alter the probability of a behaviour occurring- so they influence behaviour

What are hormones and how do they work?

• Hormones are another class of chemicals that affect behaviour
• Unlike neurotransmitters, hormones are not released by the terminal buttons of a neuron; instead, they are secreted by glands in the endocrine system
• So epinephrine (adrenaline) is released by the adrenal gland into the bloodstream as a hormone whereas norepinephrine (noradrenaline) is released by neurons in the brain as a neurotransmitter.
• Hormones are released directly into the bloodstream; as a result, they take longer to produce changes in behaviour than neurotransmitters. However they also produce effects that last a lot longer than an action potential.
• Hormones can only produce reactions in certain cells- known as target cells- that have an appropriate receptor site for the hormone. When hormone binds to the target cell, it either increases or decreases its function

What impact do they have on behaviour?

• Like neurotransmitters, hormones affect a wide range of behaviour
• There are at least fifty different types of hormones
• Some hormones act as neurotransmitters, which means they work in the brain by targeting receptor sites on the neuron’s synaptic cleft , even though the chemical is not stored in the terminal buttons, but is secreted by an endocrine gland.

The pituitary gland is the major endocrine gland- it controls the release of hormones from all other endocrine glands in the body

The main glands:

• Pituitary gland- secretes many hormones, some of which affect other glands
• Thyroid gland (affects metabolism among other things)
• Parathyroids (help regulate level of calcium in the blood)
• Adrenal glands (help trigger fight-or-flight response in the blood)
• Pancreas (regulates the level of sugar in the blood)
• Testis (secretes male sex hormones)
• Ovary (secretes female sex hormones)

Question 29

Key hormones:

Answer 29

Adrenaline- Secreted by the adrenal glands; responsible for arousal and the “fight or flight” response. Plays a role in emotional memory formation.

Cortisol- Secreted by the adrenal glands; helps control blood sugar levels and regulates metabolism, reduces inflammation and assists with memory formation (recall of information)

Melatonin- Secreted by the pineal gland; signals the relaxation and lower body temperature that help with restful sleep.

Neuropeptide Y- Produced by the hypothalamus; acts as a neurotransmitter in the brain. Stimulates food intake, reduces anxiety and stress, reduces pain perception, affects the circadian rhythm. Higher levels of NPY appear to be linked to higher levels of resilience

Oxytocin- Produced by the hypothalamus and secreted by the pituitary gland. When it affects the brain, it acts as a neurotransmitter. Plays a role in mother-child attachment; believed to play a role in social bonding and trust between people.

Testosterone- Produced by the testes; plays a facilitative role in aggressive behaviour that is, it doesn’t cause aggression, but higher levels of testosterone result in higher levels of aggression.

Question 30

Hormones and memory

Answer 30

• Adrenaline; heightens all senses and thought processes
  
  • signals release of glucose
  • Releases instant energy stored in muscles; so you have a quick burst when required (ATP reserves)
• Adrenaline: Activates the sympathetic nervous system, appears to play a role in the creation of flashbulb memory
• Cortisol: Cortisol is produced in the adrenal glands (inside the kidneys). Its functions are to increase the amount of glucose in the blood and to increase metabolism of fats, proteins and carbohydrates. It provides energy that is an important part of the “Fight or flight” response.
• It is also related to immune system functioning
• High levels, as well as having health risks, are linked to poorer performance on retrieval tasks of memory, although slightly elevated on cortisol can, over the short term, improve learning and processing information. Cortisol seems to play a role in hippocampal impairment - that is, cortisol appears to interfere with the consolidation of memory
• We know that long-term exposure to cortisol leads to hippocampal eutrophication as result of hippocampal cell death.

Question 31

McGaugh and Cahill (hormones) APFC

Answer 31

Aim:
The aim of McGaugh and Cahill’s study was to investigate the role of emotion in the creation of memories.

Procedure:
Participants were divided into two groups and shown 12 slides accompanied by different stories. One group heard a mundane story about a hospital visit, while the other group heard an emotionally arousing story involving a car accident and surgery. Two weeks later, their memory of the stories was tested through a recognition task. In a follow-up study, participants were injected with either a beta-blocker (propranolol) or a placebo before hearing the stories to inhibit amygdala activation.

Findings:
The original study found that participants who heard the emotionally arousing story had better recall of specific details than those who heard the mundane story. In the follow-up study, participants given the beta-blocker did not show better recall than those who heard the mundane story, suggesting that the amygdala’s activation is crucial for memory formation in emotionally charged situations.

Conclusion:
The study concluded that the amygdala and more specifically the stress hormone cortisol plays a significant role in the creation of memories linked to emotional arousal. The administration of beta-blockers, which inhibit the amygdala, and hormones such as cortisol, demonstrated that blocking cortisol prevents the emotional enhancement of memory.

Question 32

McGaugh and Cahill Evaluation

Answer 32

• Strengths: The ability to block adrenaline and test its effects experimentally establishes a cause-and-effect relationship between adrenaline, amygdala activation, and memory formation. The study’s findings have practical applications, such as in the treatment of PTSD.
• Weaknesses: The highly controlled and artificial nature of the study raises concerns about ecological validity. The recognition task’s limited options might not fully test memory accuracy, though significant differences in recall suggest internal validity. The standardised procedure allows for easy replication and reliability testing.

Question 33

McGaugh and Cahill Hormones Link Paragraph

Answer 33

This study by McGaugh and Cahill links to the role of hormones in human behavior by demonstrating that stress hormones like adrenaline/ cortisol play a crucial role in enhancing memory during emotionally significant events. The activation of the amygdala by adrenaline highlights how hormonal responses to stress can influence cognitive processes such as memory. The research shows that hormonal modulation can either enhance or inhibit memory formation, as evidenced by the administration of beta-blockers that prevent amygdala activation and, consequently, emotional memory enhancement. This underscores the significant impact hormones have on memory, particularly in emotionally charged situations, and provides insights into therapeutic interventions for conditions like PTSD.

Question 34

Newcomer et al (hormones) APFC

Answer 34

Aim

The aim of the study was to investigate whether high levels of the stress hormone cortisol interfere with verbal declarative memory.

Procedure

The study involved participants who were employees or students at the Washington University Medical Center. After a clinical interview to screen out participants with certain conditions, the remaining participants were matched for age and gender and randomly assigned to one of three conditions:

1. High cortisol condition: Participants took a tablet containing 160 mg of cortisol daily for four days, simulating cortisol levels found during major stress events.
2. Low cortisol condition: Participants took a tablet containing 40 mg of cortisol daily, simulating cortisol levels during minor stress events.
3. Placebo condition: Participants took a placebo tablet with no active ingredients.

Participants were given a different prose passage each day and were tested on their ability to recall the passage. The memory tests were conducted before taking cortisol, one day after starting the tablets, four days after starting the tablets, and six days after stopping the tablets.

Findings

The study found that participants in the high cortisol condition showed the worst performance in verbal declarative memory tasks compared to the low cortisol and placebo groups. There was no significant difference in memory performance between the low cortisol and placebo groups. Importantly, after stopping the cortisol tablets, the performance of participants in the high cortisol group returned to normal, indicating that the effect was temporary.

Conclusion

The study concluded that high levels of cortisol impair verbal declarative memory. The results demonstrate a clear link between cortisol levels and memory performance, suggesting that high stress can negatively impact cognitive function. However, the effects are reversible, as memory performance returned to baseline after cortisol administration was stopped.

Question 35

Newcomer et al evaluation

Answer 35

• Strengths:
  
  • The experimental design allowed for the establishment of a cause-and-effect relationship between cortisol levels and memory performance.
  • Baseline testing ensured that individual differences did not confound the results.
  • Counterbalancing the use of different prose passages controlled for potential text difficulty as a confounding variable.
• Weaknesses:
  
  • The study’s ecological validity may be limited, as memorizing prose passages is not an everyday memory task.
  • The study did not control for external stressors in participants’ lives during the experiment, which could have influenced the results.
  • Ethical concerns arise from the administration of cortisol, which temporarily impaired participants’ memory.

Question 36

Newcomer et al (hormones) link paragraph

Answer 36

This study illustrates how hormones, specifically cortisol, can significantly influence human behavior by affecting cognitive functions like memory. Cortisol, a stress hormone, was shown to impair verbal declarative memory when present in high levels, simulating a major stress event. This finding highlights the broader impact of hormonal responses to stress on human cognition, demonstrating that elevated cortisol levels can disrupt memory processes. The study also underscores the temporary nature of this effect, as memory performance normalized after cortisol levels returned to baseline, suggesting that the influence of hormones on behavior can be dynamic and reversible.

Question 37

Hormones Holistic Evaluation

Answer 37

The benefit of measuring baseline hormone levels

• one consideration when conducting research into the effect of neurotransmitters and hormones on human behaviour is that there is no real measure of what is a normal level for most of these. There is quite a wide variation of levels that are within a ‘normal’ range. Measuring an individuals increase or decrease against their own basal level would increase. the validity of the findings.
• The reductionist (reducing a complex phenomena to its basic parts) nature of attributing complex human behaviour to a single hormone
• The indirect way in which hormones are often measured e.g. through the use of beta blockers
• The difficulty of measuring hormones in a naturalistic setting
• When research is not being done using an experimental method then correlations are drawn which may be based on assumptions.