Biological Psychology Flashcards
What is the CNS made up of?
The Brain, spinal cord and neurone cells
Describe the Peripheral Nervous System
Cranial nerves and spinal nerves
Describe the Autonomic Nervous System
Heart muscle, smooth muscle, glands
Describe the Somatic Nervous System
Voluntary skeletal muscles
Describe the Sympathetic Division
“Active and alert”
Automatic involuntary response to prepare the body for stressful or threatening situations
Describe the Parasympathetic Division
“Rest and digest”
What is the function of the Frontal lobe?
Higher order processing and decision making
What is the function of the parietal lobe?
Orientation, movement and sensation
What is the function of the cerebellum?
Controls fine motor skills, coordination and balance.
What is the function of the pre-frontal cortex?
Regulating emotions and social behaviour (lack of regulation can result in aggression)
What is the function of the temporal lobe?
Auditory processing
What is the function of the limbic system? (Hippocampus and Amygdala)
Controlling and regulating emotions.
The Amygdala is the centre for emotions
The hippocampus forms new memories based on past experiences
Describe the Corpus Callosum
Connects the left and right hemispheres. It ensures both sides of the brain can communicate by sending signals to each other.
Wernicke’s area
- Understanding speech
- Lower area of left frontal lobe
Broca’s Area
- Production of speech
- Upper temporal region of left hemisphere
Function of myelin sheath
White layer of insulating fat surrounding the axon, allowing the electrical signals to move more quickly
Function of schwann cells
Forms the myelin sheath
Function of the axon
Transfers electrical impulse signals from the cell body to the synapse
Function of the soma
The cell body which contains most of the cells organelles
Function of dendrites
Receives electrical impulses from neighbouring neurons
Define saltatory conduction
The propagation of action potentials along myelinated axons from one node of Ranvier to the next, increasing the speed of electrical transmission.
Describe GABA
- Inhibitor of messages
- Calming
- Low levels linked to epilepsy
Describe Norepinephrine/Noradrenaline
- Gives attention
- Prepares for fight/flight
- Can be given to treat ADHD
Describe Acetylcholine
- Memory
- Learning
Describe Dopamine
- Pleasure feelings
- Addiction
Describe Glutamate
- Cognitive function (memory and learning)
- Brain development
- Dangerous if there’s too much
Describe Serotonin
- Happiness and good mood
- Low levels give depression
Role and function of neuron
- Pass messages between neurons using neurotransmitters.
- Electrical impulses travelling down the axon trigger the release of the neurotransmitters from the terminal at the end of the axon.
- The neurotransmitters are then released into the synaptic gap, to be picked up by receptors on the dendrites of another neuron.
Difference between presynaptic and postsynaptic neuron
Presynaptic neuron sends the message, postsynaptic neuron receives the message.
Describe synaptic transmission (8)
- Action Potential (electrical impulse) arrives at presynaptic neurone.
- Calcium channels open, influx of Calcium ions into the presynaptic neurone.
- Causes vesicles carrying neurotransmitter to move to the presynaptic membrane and fuse with the cell membrane. Exocytosis of neurotransmitter into the synaptic cleft.
- Neurotransmitter diffuses across the synaptic cleft and binds to receptors on postsynaptic membrane.
- Ligand gated ion channels on postsynaptic membrane open.
- Influx of Na+ ions at postsynaptic membrane causes depolarisation.
- Action potential in postsynaptic membrane is stimulated.
- Neurotransmitter is broken down and reuptake back into synaptic vesicles occurs via receptors in presynaptic membrane.
What is an excitatory synapse?
Increases the activity of the post synaptic membrane by depolarisation due to the influx of Na+ ions, causing an action potential to be fired.
What is an inhibitory synapse?
Decreases activity of the post synaptic membrane by hyperpolarisation due to the influx of Cl- ions, causing no action potential to be fired.
How does reuptake work?
When the neurotransmitter is absorbed back into the presynaptic neuron to be reused.
It regulates the amount of neurotransmitter in the synapse and recycles the neurotransmitter so it has a useful function.
Define recreational drugs
Drugs that are taken without medical justification for their psychoactive effects, in the belief that occasional use is not habit-forming or addictive
What is an agonist
Drugs that occupy receptors and activate them
Dopamine Reward Pathway
The structures and neurons in the brain associated with the neurotransmitter dopamine to cause feelings of reward
What is an antagonist
Drugs that occupy receptors but do not activate them. Antagonists block receptor activation by agonists
Euphoria & Dysphoria
Euphoria = high, intense pleasurable feeling
Dysphoria = low, intense anxiety or dissatisfaction
Define desensitisation (recreational drugs)
A higher concentration or dosage of a drug is required to cause the same feeling due to a loss of response at the synaptic level
Describe the effect of nicotine
- Stimulant
- Mimics Acetylcholine
- It attaches to nicotine/acetylcholine receptors which excite the neuron, causing it to release dopamine
- Causes depolarisation initiating an action potential, increasing neurotransmission
Describe the effect of cocaine
- Cocaine attaches to the reuptake receptor, blocking it so that dopamine cannot be re-absorbed back into the neuron
- This means levels of dopamine keep building in the synaptic gap, causing euphoria
- Causes continual depolarisation and stimulating action potentials
Evaluate the effect of Cocaine
+ Lewis et al (2020) proved the highly addictive nature of cocaine, which has been associated with dopamine receptors
+ Studied male mice
- Cannot generalise the findings from animal models to human behaviour; rats are not representative because they have a less complex CNS and brain anatomy than humans
Describe the effect of alcohol
- Alcohol increases the inhibitory effect of GABA, causing it to remain bound to its receptor for longer
- The post-synaptic neuron hyperpolarises, decreasing action potentials and neuronal transmission and slowing down reactions
Evaluate the effect of alcohol
+ Valenzuela and Harries (1997) found that alcohol’s inhibitory effect on memory could be related to GABA systems
+ This explains why consumption of alcohol causes the CNS reflex responses to slow down, decreasing memory
- Biologically reductionist as it fails to account for individual differences, e.g. some people have different tolerances for alcohol
Describe the effect of cannabis
- THC Binds to cannabinoid receptors
- Gives less neuron activity, impacts memory making
- Stops GABAergic neurons from inhibiting dopamine, thus there is excess dopamine
- Sedative effects on the cerebellum, analgesic affects in the brain stem
Evaluate the effect of cannabis
+ Manzares (2006) proved that high doses of cannabis resulted in hallucinogenic effects, but low doses were useful to treat diseases involving acute and chronic pain relief
- Correlation does not mean causation: Allen & Stevens (1994( showed that 50% of neurotransmission did not cause a response in the postsynaptic neuron. Other factors may influence the role of neurotransmitters, like genetics.
Evaluate the strengths of the argument for the effect of recreational drugs on transmission
+ The rewarding effects of drugs are linked to the increased release of dopamine
+ Benowitz found that nicotine binds to nicotinic receptors in the brain to facilitate neurotransmitter release.
+This led to the development of new treatment options for tobacco addiction, showing how the neurobiological explanation of a recreational drug can be used for the benefit of human understanding.
Evaluate the credibility of the argument for the effect of recreational drugs on transmission
- Animals are not representative because they possess a less complex CNS and brain anatomy than humans.
- Assumptions are made that we can apply the findings of animals studies to humans, so cause and effect is not established.
- Empirical research of recreational drugs and neurotransmission are not entirely falsifiable, decreasing the credibility of this explanation.
Evaluate the other expanations of the argument for the effect of recreational drugs on transmission
- Addiction to recreational drugs is not caused by neurotransmission, but instead by genetics.
Studies of monozygotic twins showed that if one twin had an addiction, the other twin is more likely to have an addiction. - Studies have consistently found that monozygotic twins are more likely to both have an addiction than dizygotic twins, who only share 50% DNA.
Evaluate the debates of the argument for the effect of recreational drugs on transmission
- Reductionist, because it ignores the addict’s motivation
- Freud suggests that recreational drug use is driven by a desire to escape from past traumatic experiences and to seek pleasure as a means of coping with emotional pain.
- The neurobiological explanation remains reductionist, as they fail to account for individual differences, like personality, free will, and learning how to use recreational drugs in the environment.
Evaluate the applications of the argument for the effect of recreational drugs on transmission
+ The binding of THC in the cerebral cortex causes cognitive effects. In the cerebellum, it causes sedative effects and, in the brainstem, analgesic effects.
+ Neurobiological research of the effects of drugs can be applied to drug replacement therapy (DRT) which involves giving users a substitute that produces a similar effect but in a controlled way
+ Although cannabis has hallucinogenic effects in high dosages, lower dosages might be useful to treat diseases involving acute or chronic pain. This shows that neurobiological explanations have important application for society as medicinal treatments.
Describe a CT/CAT scan
- Multiple X-ray radiation beams are passed at different angles rotating around the head to create a detailed cross-sectional image of the brain produced by a computer.
- It uses X-ray beams to view soft tissue, not just bones. X-ray beams are reduced in strength (attenuated) according to the density of the tissues in their path.
What are the advantages of a CT/CAT scan?
- Short procedure
- Identifies brain structures like tumors and lesions
- Non-invasive
What are the disadvantages of a CT/CAT scan?
- Low resolution
- Black & white, still images
- Only tell you about the structure of the brain
- Uses radiation which could be harmful in high doses as it can cause cancer
- Do not provide information on how brain activity functions, e.g. synaptic transmission
- Cannot be used for information processing
Describe an fMRI scan (Functional Magnetic Resonance Imaging)
- Involves exposure to radio waves and a magnetic field
- Images the water molecules in the body
- Monitors the uptake of oxygen by the cells in different brain regions. Active areas iof the brain consume more oxygen and can be visualised in an fMRI image. Active regions in the brain have enhanced blood flow and an increase in Oxyhaemoglobin
- This results in ‘lighting up’ of active brain regions on fMRI images when participants conducts cognitive tasks
Advantages of an fMRI
- Brain tissue and anatomical structure is recorded, a map of activation showing information and blood flow in neurones is recorded
- Safer than CT scanning because it doesn’t use X-rays
- Non-invasive because it doesn’t involve the injection of radioactive material like PET scans
Disadvantages of an fMRI
- Longer procedure (30 minutes)
- Not suitable for people with a cardiac pacemaker or metal surgical implant due to exposure to magnetic fields which can cause physical disruption to heart or organs
- Does not provide information on how actual receptors function in synaptic neurotransmission
- Patients who are claustrophobic may find the scanning unnerving, which could cause demand characteristics if this causes changes in brain activity
Describe a PET scan
Positron emission tomography
* PET scans are nuclear medicines involving the injection of a radioactive tracer into the patient
* FDG fluorodeoxyglucose travels in the bloodstream to active regions of the brain as the glucose is used up in respiration by neurone cells
* As glucose is used up, the radioactive tracer breaks down emitting positrons which radiate gamma rays
* Gamma rays are detected by scanner and active regions of the brain are identified
Advantages of a PET scan
- Brain activity can be investigated when a participant is conducting a cognitive task, including synaptic transmission and receptors
- Safer than CT scanning, as no exposure to X-rays
- Abnormal functioning of brain areas can be visualised, allowing scientists to identify and predict the impact on patients
Disadvantages of a PET scan
- Invasive procedure, involving the injection of radioactive glucose tracer
- Duration of the scan is 2-4 hours
- Can only be used once a year due to the danger of radioactive isotopes
Evaluate the strengths for the claim that there are brain structures that relate to aggression
+ Pardini found that over a 20 year period, 56 males consistently behaved aggressively. He took fMRI scans and found a strong correlation between aggression and amygdala volumes.
Evaluate the credibility of the claim that there are brain structures that relate to aggression
- Studies usually find links between brain structure and aggression, rather than clearly establishing cause and effect
- It’s more ethical to do correlational research rather than experiments, but it means that it’s impossible to establish whether a particular structure or function is a cause or effect of aggressive behaviour
Evaluate the applications for using brain structures to explain aggressive behaviours
+ If the nativist viewpoint is correct, then aggression is a biological predisposition and cannot be avoided.
+ It may be possible to identify people with extreme aggression at an early age (genetic screening, hormone testing, etc.). These individuals could be kept away from jobs or roles where they might present a danger to the public (e.g. working with children), and may be directed into other jobs like the Armed Forces, or contact sports.
+ Higher job satisfaction and productivity
Evaluate the other explanations for using the brain structures to explain aggressive behaviours
- There are many studies supporting the idea that aggression is a learned behaviour. Bandura’s “Bobo Doll” studies show that children imitate the aggressive behaviours they see in role models.
- Classical and Operant Conditioning both offer explanations for aggressive behaviour.
Evaluate the generalisability for using the brain structures to explain aggressive behaviours
- Animal studies: animals do not have the same pre-frontal cortex as humans and may not be capable of planning or self-awareness.
- Animals also express their behaviour through dominance or submission. It is possible that researchers are confusing dominant behaviour with aggressive behaviour. This would be a validity problem with the animal model if one sort of behaviour is being mistaken for another.