Biological Approach - Paper 1 Flashcards
Technology in Research
MRIs: Images from an MRI machine show cross-sections, or “slices” of the brain. The images from an MRI allow researchers to see the structure of the brain, i.e. what it looks like
- Example: For example, if someone has a brain tumour growing inside their skull, the MRI will show this. Similarly, if people are missing parts of their brain, this will show up as an empty black space in the MRI images.
fMRIs: A type of noninvasive brain imaging technology that detects brain activity by measuring changes in blood flow. An fMRI can reveal what part of the brain is active during specific functions, such as lifting your arm or even just thinking about something. Researchers and physicians can use this information to better understand, diagnose, monitor, and treat various conditions.
Technology in Research
STUDY 1: Passamonti et al
STUDY 2: Radke et al
STUDY 3: Sapolsky et al
Localization of Brain Function
Localization of brain function: Localisation of function is the idea that certain functions (e.g. language, memory, etc.) have certain locations or areas within the brain. This idea has been supported by recent neuroimaging studies, but was also examined much earlier, typically using case studies.
Localization of Brain Function
STUDY 1: Grafman et al
STUDY 2: Feinstein et al (SM)
STUDY 3: Ahs et al
Neuroplasticity
Neuroplasticity: It is defined as the ability of the nervous system to change its activity in response to intrinsic or extrinsic stimuli by reorganizing its structure, functions, or connections after injuries, such as a stroke or traumatic brain injury (TBI).
What is neuroplasticity?
Neuroplasticity is the ability of the brain to be moulded and shaped, the ability of the brain to form new neural pathways as a result of repeated experiences.
How does it happen?
Sensory stimulation can be picked up through sensory organs (eg. eyes), which can stimulate different areas of the brain as they interpret the stimulation, which can cause the different areas of the brain to interact with each other. This develops neural connections in the brain, allowing for improved structure and function.
What behaviours/environments influence neuroplasticity?
Environments with increased sensory stimulation (like pictures, toys, etc) allow for an increase in neural activity, which can increase neuroplasticity.
HOW does neuroplasticity change the brain and hence behaviour? (what happens in your brain and body)
As the brain develops greater neural connections between areas of the brain when one performs a certain task (eg. counting), the person can improve in that certain area, as well as other tasks involving the same areas.
Neuroplasticity
Study 1: Luby et al
Study 2: Sapolsky et al
Study 3: Rosenzweig and Bennet
Neurotransmission
Neurotransmitters: A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell.
Serotonin: Serotonin is a neurotransmitter, a chemical messenger that allows signals to be passed from one neuron to the next. Serotonin is released by a neuron into the synapse, the space between two neurons. Next, it attaches to receptor sites on the second neuron, allowing the electrical signal to be passed on. Finally, serotonin is either reabsorbed back into the first neuron, or is broken down by other chemicals in the synapse. Serotonin is believed to play an important role in regulating mood, sleep, and emotion.
Neurotransmission
STUDY 1: Passamonti et al
STUDY 2: Moore et al
STUDY 3: Pucilowski et al
Hormones
Hormones: Hormones are chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions. Hormones are secreted from the endocrine glands in the body. There are many types of hormones that act on different aspects of bodily functions and processes. Some of these include:
Development and growth
Metabolism of food items
Sexual function and reproductive growth and health
Cognitive function and mood
Maintenance of body temperature and thirst
Testosterone: One example of a hormone is testosterone. Testosterone is a sex hormone produced in both males and females. Testosterone is linked to behaviors of aggression and competition, causing people to be more competitive, more likely to take risks, seek higher positions within a social hierarchy, and are more likely to respond with aggression. Testosterone can either increase competitiveness in a field of passion, or increase behaviors of aggression and violence.
Hormones
STUDY 1: Radke et al
STUDY 2: Albert et al
STUDY 3: Sapolsky et al
Pheromones
Pheromones: Pheromones: chemical substances secreted by individual, smelled via olfactory system, affects behavior → attraction and formation of relationships
Example of androstadienone, which is linked to romantic attraction
Pheromones
STUDY 1: Cornwell et al
STUDY 2: Saxton et al
STUDY 3: Zhou et al
Genetics
Heritability: the extent to which a behavior can be attributed to genetics
Genetics studies often involve using twins because of the fact that fraternal/dizygotic twins have 50% of DNA in common and identical/monozygotic twins share 100% of DNA
By comparing similarities between the identical and fraternal twins, researchers can determine the heritability of certain behaviors
This idea is the basis of behavioural genetics. Behavioural geneticists study the inheritance of patterns of behaviour by investigating how much of people’s behaviour is determined by the genes they inherited from their parents and how much is caused by their environment, such as their education or their upbringing.
Genetics
STUDY 1: Raine and Baker
STUDY 2: Caspi et al
STUDY 3: Meyer-Lindenberg
Genetic Similarities
Heritability: the extent to which a behavior can be attributed to genetics
Genetics studies often involve using twins because of the fact that fraternal/dizygotic twins have 50% of DNA in common and identical/monozygotic twins share 100% of DNA
By comparing similarities between the identical and fraternal twins, researchers can determine the heritability of certain behaviors
This idea is the basis of behavioural genetics. Behavioural geneticists study the inheritance of patterns of behaviour by investigating how much of people’s behaviour is determined by the genes they inherited from their parents and how much is caused by their environment, such as their education or their upbringing.
