Biopyschology Paper 2 Flashcards
What is the nervous system?
A specialized network of cells that enables communication within the body, responsible for coordinating voluntary/involuntary processes like thought, movement and organ function
What does agnostic mean in relation to ANS?
Working in opposition to eachother
What happens to each of the organs in fight/flight mode?
Heart- Increased heart rate
Lungs- Increased intake of oxygen
Pupils- Dilated
Digestion- Slowed down
Saliva- Less saliva
What happens to each of the organs in rest and digest mode?
Heart-Normal rate
Lungs- Normal rate
Pupils- Contract
Digestion- More digestion
Saliva- Increased saliva
What is in the CNS?
Central Nervous System:
Brain- controls thought, perception and voluntary movement
Spinal cord- relays information between the brain and the rest of the body
What is the PNS?
Peripheral Nervous System:
-Transmits messaged to/from CNS to the rest of the body
What is the SNS?
Somatic Nervous System:
-Controls voluntary movements, motor neurones and sensory neurones to the CNS
What is the ANS?
Autonomic Nervous System:
-Manages involuntary processes like heart rate, digestion and transmits from/to the bodily organs
What is the Sympathetic NS?
Controls fight/flight
What is the Parasympathetic NS?
Controls rest/digest
What is a neuron?
Specialised nerve cells that form the basic building blocks of the nervous system, communicating information through electrical or chemical signals
Describe the parts of a neuron
Dendrites- receive signals from other neurons
Cell body- nucleus, controls activities and provides energy
Cell membrane- protects cell
Axon-long fibre that transmits electrical signals away from cell body
Axon hillock- Generates impulses in the neuron
Nodes of ranvier- electrical impulses jumps from node to node to speed up transmittion
Myelin sheath- insulates axon and increases speed
Axon terminal- signals are transmitted to next cell via synaptic transmittion, containing neurotransmitters
Schwann cell- produces myelin sheath
What is the structure and function of a sensory neuron?
Structure- Long dendrites, short axon and cell body in middle
Function- Carries info from sensory organs to CNS like heat or pressure
What is the structure and function of a relay neurone?
Structure- Short dendrites, short axon, lack of myelin sheath as less speed is needed
Function- Found only in CNS, connects motor and sensory neurones
What is the structure and function of a motor neurone?
Structure- Short dendrites, long axonss, cell bodies in CNS, spinal cord
Function- Transmits signals from CNS to effectors enabling movement
How can the reflex arc be remembered?
Sausage Roll Sausage Roll M E
What is synaptic transmittion?
A process by which neighbouring neurons send messages. A signal is released from the presynaptic and received by receptors at the postsynaptic
What kind of signals are ones within a neuron?
Electrical
What kind of signals are ones between neurons?
Chemical
What are synaptic vesicles?
Holds neurotransmitters which are released when an electric impulse reaches the presynaptic terminal
What are neurotransmitters?
Brain chemicals that relay signals across neurons via the synapse which are excitatory or inhibitory
What is excitation?
Increased positive charge of the postsynaptic neuron which increases the chance of the electrical signal being passed on
What is the higher chance of an electrical signal being passed on called?
Depolarisation
What is inhibition?
Increased negative charge of the postsynaptic neuron which decreases the likelihood of passing on the electrical impulse
What is the lower chance of an electrical signal being passed on called?
Hyperpolarization
What are examples of excitation and inhibition as chemicals?
Excitation- Adrenaline
Inhibition- Seretonin
What is summation?
The process where the effects of multiple excitatory and inhibitory signals received by a neuron are integrated to determine whether the neuron will fire an action potential
Where does summation occur?
Axon hillock
Outline the process of synaptic transmission
- The electrical signal reaches axon terminal
2.Vesicles in pre-synaptic membrane is triggered, releasing neurotransmitters via diffusion which turns into it into a chemical signal
3.Chemical locks into pre-synaptic receptor sites, found only in membrane of adjacent post-synaptic neuron which converts it back to an electrical impulse
4.Stimulation of post-synaptic reception results in excitation or inhibition via summation
5.If total effect is inhibitory, negative and less likely. If total effect is excitatory, positive and more likely
6.Enzymes are released to break down the excess neurotransmitters
6.Or, excess neurotransmitters are reabsorbed by the synaptic terminals
8.Vesicles are replenished with new/reused neurotransmitters
What is dopamine related to?
Pleasure, satisfaction, motivation, mood, memory, sleep
What is seretonin related to?
Mood, sleep, digestion, nausea
What is adrenaline related to?
Fight/flight response in stressful situations
What is the endocrine system?
A network of glands which secrete hormones into the bloodstream to regulate physiological processes
What are glands?
Specialised organs which secrete substances like hormones, enzymes and other fluids- examplea are pituitary, adrenal, thyroid
What are hormones?
Chemical messengers produced by endocrine glands and released into bloodstream to target organs and tissues with growth and metabolism
What are the different areas of the endocrine system?
Hypothalamus
Pituitary gland
Parathyroid gland
Adrenal gland
Pancreas
Testes
Thyroid gland
Ovaries
What is the hypothalamus?
Makes dopamine, control heart rate, blood pressure, temperature, controls pituatary gland, thirst and hunger
What is the pituatary gland?
Growth, sexual reproduction, metabolism, produces LH and FSH
What is the parathyroid gland?
Calcium levels
What is the adrenal gland?
Releases adrenaline, diverts blood to muscles/brain, blood pressure, metabolism and response to stress
What are the ovaries?
Produces eggs for fertilisation, menstrual cycle
What are the testes?
Makes sperm and testosterone
What is the pancreas?
Digests food with enzymes, makes insulin to control blood sugar levels
What is the thyroid gland?
Controls thyroxine and metabolic rate. It produces the hormone thyroxide which affects heart rate. It affects cells throughout the body, increasing metabolic rate, affecting growth rate
What are the hormones from the thyroid gland?
Hypothyroidism- too low, depression, slow movement, weight gain, tiredness
Hyperthyroidism- nervousness, anxiety, hyperactivity, weight loss, insomnia
What is oxytocin?
‘Love’ hormone, cuddle, bonding, helps with contractions and shrinking of the uterus, released during breastfeeding, involved in mother-child bonding process
How does the endocrine and ANS work together?
-A person enters a stressful/dangerous situaton
-The amygalda is activated, sending a distress signal to hypothalamus
-The hypothalamus activates SAM pathway to adrenal gland which changes resting state to sympathetic state
-SNS stimulates adrenal mendulla
-Adrenal mendulla secrets adrenaline and noradrenalline into the bloodstream
-Adrenaline causes physiological changes like increased oxygen rate, heart rate
How does the body respond to prolonged stress?
What is spatial resolution?
The smallest feature a scanner can detect. It allows pyschologists to distinguish different brain regions
What is temporal resolution?
Accuracy of scanner in time, how quickly it detects brain activity
What are functional scans?
Differences in brain function of different areas or overall
What are structural scans?
Assessing areas of damage/atypical brain regions
Describe a profile of fMRI’s.
-Detects change in blood oxygenation and flow due to neural activity, creating 3D activation brain maps
-Functional analysis/purpose
-High spatial resolution (1-2mm)
-Low temporal resolution (1-4 secs)
Describe a profile of EEG’s.
-Measures electrical activity in brain via electrodes that are fixed into the scalp, generating brainwaves which diagnose arrhythmic patters of activity related to diagnosis of disorders
-Functional analysis- provides overall indication of brain waves present
-Low spatial resolution
-High temporal resolution (1-10ms)
Describe a profile of ERP’s.
-Statistical averaging technique which measures a specific brain wave in relation to a specific activity/task/stimuli
-Functional analysis to produce info about brain waves
-Low spatial resolution
-High temporal resolution (1-10ms)
Describe a profile of post-mortems.
-Analysis of a person’s brain after death to assess areas of structural abnormalities which may impact behavioural or cognitiive factors
-Structural processes to asses areas of damage
-High spatial resolution as able to dissect
-Low temporal resolution as only one measurement is taken
What are the strengths and weaknesses of fMRI?
Strengths- Doesn’t rely on radiation which is more ethical
-High spatial resolution
-Helps plan safe surgeries and is used widely in research
Weaknesses- Expensive
-Impossible for causation on neural level
-Poor temporal resolution
What are the strengths and weaknesses of EEG?
Strengths- Sleep studies/epilepsy studies
-Non-invasive
-Ethical as no radiation is involved
-Cheaper than fMRI
Weaknesses- Low spatial resolution detecting information from a generalised area of thousands of neurons
-Uncomfortable
What are the strengths and weaknesses of ERP?
Strengths- High temporal resolution
Specific measurement of processing changes with stimulus
-Non-invasive
-Cheaper than fMRI
Weaknesses- Not possible to eliminate extraneous variables
-Low spatial resolution
-Uncomfortable
What are the strengths and weaknesses of post mortems?
Strengths- Vital in understanding the brain with Wernicke
-High spatial resolution as deeper regions can be examined
Weaknesses- Invasive
-Lack of causation as changes may occur after death
-Ethical issues with consent and specific permission
What is diffusion tractography?
A type of MRI application that visualizes the anisotropic diffusion of water molecules along fiber bundles in the brain
What is localisation?
Different functions are localised in specific areas of the brain
What is lateralisation?
Certain activities and behaviours are controlled by one hemisphere rather than another
What and where is the frontal lobe?
Front of the brain
Responsible for thought, movement, memory and social skills
What and where is the temporal lobe?
Behind the ears
Auditory area- analyses speech based information
What and where is the occipital lobe?
Back of the brain
Visually processing area- distance, depth, perception, colour
What and where is the parietal lobe?
In between the somatosensory lobe and occipital lobe (right upper back)
Sensory perception and integration like hearing, taste, sight, touch and smell
Where and what is the somatosensory cortex?
Parietal lobe
Sensory information from the skin like heat or pressure is presented
Where and what is the auditory cortex?
Temporal lobe
Ability to perceive sound
Where and what is the motor cortex?
Frontal lobe
Planning, controlling and executing voluntary movement
Where and what is the visual cortex?
Occipital lobe
Receives, integrates and processes visual information from retinas
What is Broca’s area and what is damage to it?
Small area in left frontal lobe responsible for speech production
Broca’s aphasia- Slow speech, lack of fluency
What is Wernicke’s area and what is damage to it?
Left temporal lobe responsible for language comprehension
Wernicke’s aphasia- Neologism
What evidence supports localisation and why?
Buckner and Petersen (1996)- episodic and semantic memories are in different hemispheres of the brain/prefrontal cortex
Phineas Gage- Personality changed after direct link to frontal lobe
Broca’s study of Tan- Visual damage to Broca’s area related to speech production
What evidence denies localisation and why?
Dougherty et al. (2002)- Neurosurgey for OCD (cingulotomy) was 30% successful for participants after 32 weeks
What is contralateral?
In relation to the opposite side of the body where the structure/condition occurs
What is ipsilateral?
Belonging/occuring on the same side of the body
What functions are not lateralised?
Movement, senses and vision- Motor/somatosensory areas
Describe sensorimotory processing.
Motor actions are controlateral which means the activity of right side of the body is controlled by the left hemisphere and the activity of left side of the body is controlled by the right hemisphere.
Describe visual processing.
Visual actions is both controlateral and ipsilateral as each eye gets light from the left field of vision but it goes to the right cortex. This allows for vision to understand depth and perception through the optical chiasm.
What is split brain research?
Severing the corpus callosum between the hemispheres as a surgical procedure used for epileptic inidvdiuals to reduce fits. The brain may experience excessive electrical activity between hemispheres and the split brain shows how the hemispheres can function without communication.
What was the aim of Sperry’s experiment?
To study how the seperated hemispheres deal with speech and vision
What was the sample and method of Sperry’s experiment?
11 people were shown an image projected to a participants right field of vision and the same/different image was projected on the left field of vision
What conclusions were made from Sperrys’s experiment?
The RH processes information where the language centre isn’t which means speech was not used to describe the image, although they could draw with their left hand the picture seen. The LH processes information where the language centre is which means speech could be used to describe the image. Vision is both contralateral and ipsilateral.
What was the Kim Peek case study?
He had damage to his cerebellum and corpus callosum was missing. He had an incredible memory and could read two pages of a book at once.
Name studies which approved of laterlisation and why?
Rogers et al- Chicks not lateralised couldn’t attend to two visual tasks simultaneously whereas laterlised chicks could
Gazzaniga- Presented stimuli to each hemisphere seperately and at the same time. He worked with Sperry- the right/left hemispheres were found to be independent
What are the strengths of split brain research?
-Enabled discoveries of lateralisation of function- we may not be as aware of how each hemisphere works without it
-Scientific experiments in lab conditions which increases replicability
What are the weaknesses of split brain research?
-Lack of control groups
-Rare, unique case studies
-Participant variables- how long had their brain been split for?
-Artificial as they would be able to see irl with both eyes
-Oversimplifies lateralisation
What is neural plasticity?
The ability for the brain to change and adapt its structure as a result of experience or new learning
What is functional recovery?
The way certain abilities of the brain may be moved or redistrbuted rather than lost during brain damage or trauma
What is synaptic pruning?
Rarely-used connections are deleted whereas frequently-used connections are strengthened as we age
What is spontaneous recovery?
Process of functional recovery is very quick then slows down over time
What are the strutural changes of functional recovery?
Axonal sprouting, reformation of blood vessels, denervation supersensitivity, recruitment of homologous areas
What is axonal sprouting?
The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
What is the reformation of blood vessels?
Facilities the growth of new neural pathways
What is denervation supersensitivity?
Similar areas become aroused of higher levels to compensate for ones that are lost. This can lead to oversensitivity like messages of pain
What is synaptic pruning?
Process where rarely-used connections are deleted whereas frequently-used connections are strengthened
Summarise Maguire’s study on neural plasticity
Taxi driver study:
-Used a matched control group to compare
-Hippocampus associated with spatial and navigation skills
-Taxi drivers have more volume grey matter in hippocampus
-The longer the taxi drivers have had the job, the more pronounced the structural difference (positive correlation)
Summarise Draganski’s research
Medical students before/after revision:
-Learning-induced changes in the posterior hippocampus and parietal cortex
-Intensive study causes structural changes
Summarise Kuhn’s et al research
Video games study:
-Super Marios 30 minutes daily for 2 months which led to an increase of grey matter in hippocampus
-Memory/co-ordination skills increased
Summarise Davidson’s et al research
Tibetan monks study:
-Higher gamma wave activity (neural co-ordination) for meditators than non-meditators
-Meditation can leave lasting changes on brain function
What are examples of functional recovery?
Epileptical Jody- had right hemisphere removed and she walked normally after
Echolocation Daniel- used echolocation (sounds to aid sight) - Thater et al (2011)- echolocation activates blind peoples visual parts of their brain
Outline Tajiri et als study (2013)
Stem cells were provided to rats after brain trauma which led to neuron-like cell development suggesting brain damage can be prepared
Outline Elbert et als study (2014)
Neural reorganisation capacity is greater in children than adults as adults have reduced generative abilities
Outline Banjerjee et al.’s study (2014)
Treated stroke patients with stem cells (100% recovery rate compared to typical 4% rate). However, it is limited by its small sample size and lack of control group
What is a circadian rhythm?
24 hour rhythms such as the sleep/wake cycle and core body temperature
What is an infradian rhythm?
Rhythms taking longer than 24 hours such as the menstrual cycle
What is an ultradian rhythm?
Shorter cycles that occur multiple times in 24 hours
What are endogenous pacemakers?
The body’s internal clock like the superchiasmatic nerve (SCN)- a tiny bundle of nerve cells in the hypothalamus in each hemisphere which is connected to the optic nerve, receiving light
What are exogenous zeitgebers?
External changes in the environment that reset our biological clocks such as social cues and light
Explain the cycle of the core body temperature
Lowest at early hours of the morning (36 degrees at 4.30am) for alertness and highest in early evening (38 degrees at 6pm) for tiredness
Explain light as an exogenous zeitgeber
Light can reset the SCN. Ganglion cells in the retina detect light sensitivity and brightness, sending information to the optic nerve then the superchiasmatic nuclei.
What is Bolvin et al. (1996)’s study on shift work and mistakes?
Night worker engaged in shift work experience a period of reduced construction around 6am meaning accidents were more common
What is Knutson (2003)’s study on shift work and poor health?
Shift workers are 3x more likely to develop heart disease than people who work more typical sleep patterns. This shows the economic implictions in real-life
What is Bonten et al (2015)’s study on medicines?
Rise and fall of heart rate, digestion, and hormone levels have led to chronotherapeutics like how aspirin is most effective taken last thing at night for heart attacks
What do Wolfson and Carskadon suggest?
School should start a couple of hours later to fit the teenage chronotype.
What did Decoursey et al (2000)’s study show?
He destroyed SCN connections in the brains of 30 chimpunks and their sleep/wake cycle disappeared, dying from predators.
Explain melatonin levels in association to circadian rhythms
Melatonin levels fall during daylight hours and begin to rise as daylight increases. Levels peak during darkness and night hours
What is Siffre’s cave study?
Conducted a case study in 1973 where he spent two months in a cave without light. His circadian rhythm was 24-25 hours which meant it had gained in length and exogenous zeitgebers have control
What are limitations of Siffres 1963 study?
His case study is not generalisable to all due to individual differences, lacking population validity. It was also not peer reviewed
What is the menstrual cycle as an infradian rhythm?
-Occurs every 28 days
-Rising oestrogen levels cause an egg to be released from an ovary
-Egg travels down the oviduct to the womb
-Rising progesterone levels thicken the lining of the womb
-If the egg is not fertilised, it is shed
What is SAD as an infradian rhythm?
-Seasonal Affective Disorder impacts specifically during winter months when days are darker and longer
-More melatonin is secreted leading to higher levels of depression
-Serotonin is implicated in the sleep wake cycle so disrupted levels of this neurotransmitter is likely to lead to imbalances in mood
What does McClintock and Stern’s 1998 study on the menstrual cycle show?
-29 women in the study gave sample of pheromones from the armpits of women to inhale and samples were taken throughout the usual menstrual cycle
-68% of participants found their menstrual cycle had aligned with that of the pad donor
-Research concluded synching of the menstrual cycle has evolutionary advantages like how all women in one tribe if fallen pregnant at the same time can help with child care
What does Rosen et al’s 1990 study about SAD show?
-A large scale survey of adults who lived in multiple states in the US
-Measured prevalence rates of winter SAD and summer SAD- winter SAD rates were higher the more northern the state was
-No correlation between northern/southern states and summer SAD
-Research concluded that living with more longer, darker days in a more northern latitude leads to a higher likelihood in developing SAD
What are strengths and weaknesses of McClintock and Stern’s 1998 study?
-Longitudinal field study which means changes over time could be tracked which increases validity
-Compromised by extraneous variables like the women’s diet and exercise- it wasn’t controlled
What are strengths and weaknesses of Rosen et al’s study?
-Large scale study, large sample with good reliability. Standardised questionnaire which increases replicability
-Lacks explanatory power as there may be other reasons for SAD like life events and the extent/quality of SAD is not documented
What are the ultradian rhythm stages of sleep?
Stage 1/2- Light sleep, slow alpha waves, theta waves show a deeper sleep, sleep spindles occur in stage 2
Stage 3/4- delta waves of deep sleep, greater amplitude, takes longer to wake up
Stage 5- REM sleep, dreaming occurs, rapid eye movement as eyeballs are active and brain activity speeds up
-75-80% of sleep time is in NREM
What is Dement and Kleitman’s 1957 study on REM sleep and dreams?
-A sample of 5 participants studied intensively
-In a sleep lab with no alcohol or caffeine before experiment
-EEG machine used to track brain waves
-Woken at specific intervals to ask if they were dreaming
-Positive correlation between REM sleep and dreaming
-Vertical eye movements linked with dreams of ladders, climbers whereas horizontal eye movements linked to people throwing things at eachother
What are strengths and limitations of Dement and Kleitman’s 1957 study?
Strength- Well controlled eliminating confounding variables like caffeine and alcohol intake which increases reliability. Replications have supported findings which increases validity
Weaknesses- 5 participants decreases generalisability and external validity. Temporal validity as in the 1950s, the use of digital technology did not exist which may now interfere with ultradian rhythms