Biopsychology Flashcards
What is the nervous system?
A highly specialised network of cells in the human body and is our primary internal communication system
What is the nervous system made up of?
Billions of neurons (nerve cells)
What are the 2 main functions of the nervous system?
- The control of behaviour
- The regulation of the body’s physiological functions
What are the two branches off of the nervous system?
The central nervous system and peripheral nervous system
Correctly draw the tree diagram of the breakdown of the nervous system
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Summarise the function of the brain
Recieves and processes sensory information, initiates responses, stores memories, generates thoughts and emotions
Summarise the role of the spinal cord
Passes signals between the brain and PNS. Also control reflex responses
What does the peripheral nervous system do?
It relays nerve impulses from the CNS (the brain and spinal cord) to the rest of the body and from the rest of the body to the brain
What are the divisions of the peripheral nervous system?
The somatic nervous system and the autonomic nervous system
What is the main function of the SNS?
Carries sensory information from sensory organs to the CNS and relays motor commands to muscles; controls voluntary movements
What type of neurons does the SNS control?
Sensory neurons and motor neurons
What is the ANS responsible for?
Responsible for functions that keep the body in a stable state (homeostasis)
What type of neurons are found within the ANS?
Preganglionic neuron and the postganglionic neuron
Summarise the role of the sympathetic nervous system
Prepares the body for action or stress - ‘fight or flight’
Summarise the role of the parasympathetic nervous system?
Calms the body and conserves energy - ‘rest or digest’
What are the similarities between the brain and the spinal cord?
Both control involuntary processes(e.g. the brain stem controls breathing and the spinal cord controls involuntary reflexes)
What are the differences between the brain and the spinal cord?
The brain provides conscious awareness and allows for higher order thinking, while the spinal cord allows for simple reflex responses. The brain consists of multiple regions responsible for different functions, whereas the spinal cord has one main function
Correctly label a neuron
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Provide the description and role of a sensory neuron
Sensory neurons are found in receptors such as the eyes, ears, tongue and skin, and carry nerve impulses to the spinal cord and brain. When these nerve impulses reach the brain, they are translated into ‘sensations’, such as vision, hearing, taste and touch. However, not all sensory neurons reach the brain, as some neurons stop at the spinal cord, allowing for quick reflex actions
Provide the description and role of a relay neuron
Relay neurons are found between sensory input and motor output/response. Relay neurons are found in the brain and spinal cord and allow sensory and motor neurons to communicate
Provide the description and role of motor neurons
Motor neurons are found in the central nervous system (CNS) and control muscle movements. When motor neurons are stimulated they release neurotransmitters that bind to the receptors on muscles to trigger a response, which lead to movement
Identify a sensory neuron, relay neuron and motor neuron
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Summarise the process of synaptic transmission
- Electrical impulses pass down the axon of the first neuron
- Vesicles containing neurotransmitters move towards the pre-synaptic membrane
- Vesicles fuse with the pre-synaptic membrane and release neurotransmitter into the synaptic cleft
- Neurotransmitters diffuse across the synapse and attach to receptors on the post synaptic membrane
- Activity in the receptors cause a change in the second neuron which increases or decreases the likelihood of an action potential in the second neuron
- Neurotransmitter molecules are reflected into the pre-synaptic neuron
- An electrical impulse is then triggered again and travels down to the end of the axon
Correctly label synaptic transmission
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What are neurotransmitters?
Neurotransmitters are chemicals that are released from the end of brain cells(neurons) and allow them to communicate with each other and relay messages to different areas/structures of the brain. As one neuron releases a neurotransmitter, receptors on other neurons pick up this message and ‘relay’ this to the next neuron
Explain the difference between excitatory & inhibitory neurotransmitters
Excitatory neurotransmitters have excitatory effects on the neuron. This means they increase the likelihood that the neuron will fire an action potential. Inhibitory neurotransmitters have inhibitory effects on the neuron. This means they decrease the likelihood that the neuron will fire an action
What is the role of adrenaline in the body?
Adrenaline triggers the body’s fight or flight response. This reaction causes air passages to dilate to provide the muscles with the oxygen they needs to either fight dangers or flee. Triggers blood vessels to contract and re-direct blood
What is the role of GABA in the body?
It blocks, or inhibits certain brain signals and decreases activity in your nervous system. When GABA attaches to a protein in your brain known as a GABA receptor, it produces a calming effect. This can help with feelings of anxiety, stress, and fear
What are hormones defined as?
A regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action
In the endocrine system effects on behaviour are caused by what?
Hormones
In the endocrine system their effects are what?
Slow but long lasting
In the nervous system effects on behaviour are caused by what?
Neurotransmitters
In the endocrine system their effects are what?
Quick but short lived
What are the 4 ways of studying the brain?
- Post mortem examinations
- Functional Magnetic Resonance Imaging (fMRI)
- Electroencephalogram (EEG)
- Event-related potential (ERPs)
Give a description of fMRI
A brain scanner which measures increased blood flow to brain sites when individuals are asked to perform cognitive/physical tasks. Increased blood flow indicates demand for oxygen in that area. This produces 30 images showing which parts of the brain are involved in a particular mental process, important for understanding of localisation.
Give a strength of fMRI
Non invasive - no insertion of instruments unlike PET and no exposure to radiation- beneficial to the economy as there is no recovery time as people don’t have to be off work
Give 2 weaknesses of fMRI
- fMRI only measures blood flow - it cannot home in on the activity of individual neurons therefore it’s hard to tell exactly what brain activity is being represented in the screen
- Expensive and it can only capture a clear image if the person stays still
Describe post mortem examinations
Brains from dead individuals who displayed cognitive abnormalities whilst alive can be dissected to check for structural abnormalities/damage
Give 2 strengths of post mortem examinations
- Deep structures of the brain can be investigated after death - PM is more appropriate than EEG or ERP when examining any brain structure other than the neocortex
- Highly applicable - Broca and Wernickle both relied on post mortem studies in establishing links between language, brain and behaviour
Give 2 weaknesses of post mortem examinations
- Ethical issues
2. The issue of causation
Describe EEG
Measures electrical activity in the brain using electrodes attached to the scalp, and measures how electrical activity in the brain varies over time/in different ways
What are the 4 basic brain wave patterns?
- Alpha
- Beta
- Delta
- Theta
What is occurring during beta
The individual is awake and slightly aroused or in REM
What is occurring during delta
Deep sleep
What is occurring during theta
Light sleep
Give 2 strengths of EEG’s
- Medical applications in diagnosing disorders such as epilepsy and alzheimer’s
- Non-invasive - no insertion of instruments unlike PET and no exposure to radiation
What can EEG readings detect?
Epilepsy and Alzheimers
Give 2 weaknesses of EEG’s
- Only monitor electrical activity in outer layers of the brain, therefore, cannot reveal electrical activity in deeper brain sites
- Not highly accurate - cannot distinguish differences in activity between 2 closely adjacent areas
Describe ERP’s
Electrodes are attached to the scalp to measure small voltages of electrical activity when a stimulus is presented. Because these small voltages are difficult to pick out from other electrical signals in the brain, the stimulus need to be repeatedly presented, and only signals which occur every time the stimulus is presented will be considered an ERP for that stimulus
Give 2 strengths of ERP’s
- ERPs provide a continuous measure of neural activity in response to a stimulus. Therefore, changes to the stimulus can be directly recorded
- Non invasive
Give 2 weaknesses of ERP’s
- Only monitor electrical activity in outer layers of the brain
- Lack of standardisation in methodology between studies
What is localisation?
The theory that specific areas of the brain are associated with particular physical and physiological functions
How is the left and right hemisphere connected?
By a bundle of fibres called the corpus callosum
What does the corpus callosum do?
Enables messages to enter the right hemisphere to be conveyed to the left hemisphere and vice versa
What are the 4 divisions of each hemisphere?
- The frontal lobe
- The parietal lobe
- The temporal lobe
- The occipital lobe
What is hemispheric lateralisation?
Refers to the brain understanding that one side controls the opposite side of the body and processes information in the opposite visual field, and that each hemisphere is responsible for different functions
What is the function of the motor cortex?
Involved in the planning, controlling and execution of voluntary movement
What is the function of the somatosensory cortex?
Responsible for processing somatic sensations. These sensations arise from receptors positioned throughout the body that are responsible for detecting touch, proprioception, nociception and temperature
What is the function of the visual cortex?
To receive, segment, and integrate visual information
What is contralateral?
The brain is contralateral, meaning the left hemisphere controls the right side of the body and vice versa
What is the function of the auditory cortex?
Plays a critical role in our ability to perceive sound. It is thought to be integral to our perception of the fundamental aspects of an auditory stimulus, like the pitch of the sound
What is the function of the Wernicke’s area?
Involved in language processing/comprehension
What is the function of the Broca’s area?
Utilised in speech production, and regulates breathing patterns whilst speaking
What mostly occurs in the left hemisphere?
Language processing
What mostly occurs in the right hemisphere?
- Recognising emotion
2. Spatial relationships
What are the two main language processing areas?
Broca’s area and Wernicke’s area
Write a brief summary of Broca’s study of Tan
Tan could understand spoken language but was unable to produce any coherent words and could only say ‘tan’. After Tan’s death, Broca conducted a post mortem examination on Tan’s brain and discovered that he had a lesion in the left frontal lobe. This led Broca to conclude that this area was responsible for speech production. People with damage to this area experience Broca’s aphasia, which results in slow and inarticulate speech
Write a brief summary of the case study of HM
Molaison allowed surgeons to remove a thumb sized section of tissue from each side of his brain. It was an experimental procedure that he and his surgeons hoped would quell the seizure wracking his brain, and it worked. The seizures abated, but afterwards Molaison was left with permanent amnesia. He could remember some things, but he was unable to form new memories.
Write a brief summary of the case study of Phineas Gage
A metre length pole went through his left cheek passing through his left eye and exiting his skull taking a portion of his brain with it. Incredibly, Gage survived. Gage experienced initial problems with his speech and lost sight in his left eye, however he recovered remarkably well with no marked effect on his functioning. However, psychologically he was a changed man, before the accident he was reported as calm and well mannered however following the event he showed hostile, rude behaviour and used vulgar language.
What is the law of equipotentiality?
Different areas of the cortex have similar capacities to process learning and therefore one area can take over functions if another area is damaged meaning that only large lesions affect learning.
What did Dannelie do?
Investigated a case of an Italian boy who had most of his left hemisphere removed by age 2 and a half to remove a tumour. With intensive therapy, his right hemisphere was able to take over almost all of the functioning that would normally have been done by the left
What is a split brain patient?
Split brain patients are those who have had the connection between the left and right hemisphere severed.
When a word was projected to the left visual field, what couldn’t the split brain patients do?
Identify the word, patients recorded it as ‘just a flash’ or didn’t notice it at all
If a word was projected to the right visual field, what could split brain patients do?
Participants could describe in speech/writing
Define plasciticy
The brain’s ability to change and adapt (functionally and physically) as a result of experience and new learning
What is synaptogenesis?
It is where new synapses are formed. This can occur throughout life but during infancy there’s an explosion of synaptic formation (known as exuberant synaptogenesis)
What is neurogenesis
Neurogenesis refers to when new neurons are grown. In infancy this is responsible for populating the growing brain with neurons, but also occurs in adulthood
What is synaptic pruning?
The process of synapse elimination that typically happens between early childhood or puberty. However, this has also been shown to occur to a lesser extent in adulthood
Who can be used as supporting evidence for plasticity
Kuhn et al
Maguire et al
What did Kuhn et al do?
Illustrated the potential benefits of playing super mario for 2 months playing at least 30 minutes per day. They found significant increases in areas of the brain (e.g the hippocampus, the cortex and the cerrebellum) responsible for key behaviours such as working memory, planning and motor performance. Therefore, it can be concluded that the complex cognitive demands involved in mastering a video game caused the formation of new synaptic connections in brain sites controlling spatial navigation, planning, decision making, etc.
What did Maguire et al do?
Studied the brains of London taxi drivers using an MRI and found significantly more grey matter in the posterior hippocampus than in the matched control group. This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. As part of their training, London cabbies must take a complex test called ‘the knowledge’, which assesses their recall of the city streets and possible routes. It is also noteworthy that the longer they had been doing the job, the more pronounced was the structural difference
What are the structural and functional changes that allow the brain to adapt to trauma?
- Neural regeneration
- Neuronal unmasking
- Neural reorganisation
What is neural regeneration?
This is also known as axon sprouting and occurs when new nerve endings grow and connect with undamaged areas. This can compensate for damaged areas and enable the recovery of previously lost functioning. This can be seen as a type of synapticgenesis
What is neuronal unmasking?
This occurs when ‘dormant synapses’ in the brain (neural connections which exist anatomically but have no function) are opened and become functional. This cam occur when a surrounding brain area becomes damaged, as the rate of input to these dormant synapses would increase opening up connections to regions of the brain that are not normally activated and allows the gradual development of new structures. This can be seen as a type of neurogenesis
What is neural reorganisation?
This occurs when the brain transfers functions from the damaged area to undamaged sections of the brain. For example, if Broca’s area in the left hemisphere was damaged then an area on the right hemisphere might take over. In extreme cases (and with intensive therapy) whole areas of the brain can take over the functions of damaged sections
Who can be used as supporting evidence for functional recovery after trauma?
Danelli
Schneider
What did Danelli do
Investigated a case of a boy who had most of his left hemisphere removed aged 2 and a half to remove a tumour. With intensive therapy, his right hemisphere was able to take over almost all of the functioning that would normally have been done by the left
What did Schneider do?
769 people who had suffered head injuries from road traffic accidents and falls were studied. They had all been treated in the emergency room in the hospital and followed a programme of rehabilitation. Their progress was monitored
What does the nucleus of a neuron do?
Contain all the genetic material of the cell
What do dendrites do?
Carry impulses from other neurons towards the cell body
What does the axon do?
Carries the impulses away from the cell body down the length of the neuron
What does myelin sheath do?
Protects the axon and speeds up the elctrical impulses
What do nodes of Ranvier do?
Speed up the transmission of the impulse by forcing it to ‘jump’ across gaps along the axon
What do terminal buttons do?
Communicate with the next neuron in the chain across a synaptic gap by using neurotransmitters
What is the nervous system made up of?
Neurons
What are the 7 parts of the structure of neutrons
- Terminal buttons
- Dendrites
- Nucleus
- Axon
- Cell body
- Myelin sheath
- Nodes of Ranvier
