Biopsychology

Question 1

The Central Nervous System

Answer 1

the CNS has 2 main functions:
control of behaviour
regulation of the body’s physiological processes.
to do this, the brain must receive messages from the senses and must be able to send messages to the muscles and glands of the body. this involves the spinal cord and the nerve cells that are attached to the brain and run the length of the spinal column.

Question 2

The Central Nervous System: Describe the spinal cord

Answer 2

the function is to relay information between the brain and the rest of the body. this allows the brain to monitor processes such as digestion and breathing and also coordinate the voluntary muscles. the spinal cord is connected to the rest of the body by nerves that connect to muscles and glands. e.g. spinal nerve which branches off from the thoracic region of the back carries messages to and from the chest and abdominal region.
the spinal cord also contains circuits of nerve cells that enable us to perform simple reflexes without the involvement of the brain e.g. pulling a hand away from the hot oven.
damage to the spinal cord prevents the brain from relaying messages therefore below the damage site will stop working.

Question 3

The Central Nervous System: describe the Brain

Answer 3

The brain can be divided into 4 parts:
cerebrum
cerebellum
diencephalon
brain stem

Question 4

The Central Nervous System: describe the
4 parts of the brain

Answer 4

cerebrum: this is the largest area of the brain and is divided into 4 lobes. e.g. frontal lobe= thought and speech production. occipital lobe= processing of visual images. the cerebrum is split down the middle into 2 hemispheres. each hemisphere has specific functions and they communicate with each other via the corpus callosum.
cerebellum: this coordinates motor skills and balance, coordinating the muscles to allow for precise movements. abnormalities in this area can cause issues with speech and motor problems.
diencephalon: this lies at the top of the brain stem. within this area is the thalamus and the hypothalamus. the thalamus is a relay station for nerve impulses coming from the sense routing them to appropriate parts of the brain where they can be processed. the hypothalamus has a number of functions such as the regulation of body temperature, hunger, and thirst. it also acts as a link to the endocrine system that releases hormones from the pituitary glands.
brain stem: this is responsible for regulating automatic functions such as breathing, heartbeat, and swallowing. motor and sensory neurons travel through the brain stem allowing impulses to pass between the brain and spinal cord.

Question 5

what is the Peripheral Nervous System?

Answer 5

the nervous system outside of the CNS make up the peripheral nervous system. this system relays nerve impulses from the CNS to the rest of the body and back to the CNS. there are 2 main divisions: somatic and autonomic nervous systems.

Question 6

The Peripheral Nervous System: what is the Somatic Nervous System?

Answer 6

this is made up of 12 cranial nerves (emerge from the underside of the brain) and 31 pairs of spinal nerves (these emerge from the spinal cord). these nerves have both sensory and motor neurons.
sensory = relays message TO the CNS
motor = relays information FROM the CNS.

Question 7

The Peripheral Nervous System: describe the autonomic nervous system

Answer 7

the body carries out some functions that we are unaware of such as heart beat and digestion. this system is essential as these functions would not work properly if we had to think about them. the ANS has 2 parts: sympathetic and parasympathetic. these both regulate the same organs but have opposite effects. the sympathetic nervous system is associated with the neurotransmitter noradrenaline and the sympathetic nervous system is associated with acetylcholine.

Question 8

The Peripheral Nervous System: describe the Sympathetic Nervous System

Answer 8

this system helps us deal with emergencies. the neurons travel to virtually every organ and gland, preparing them for rapid action.
Stress response: pupils dilate which means increased light and better vision, increased heart beat and blood rate, and low saliva which means we have a dry mouth.

Question 9

The Peripheral Nervous System: describe the Parasympathetic Nervous System

Answer 9

The SNS pushes an individual into action, and the PNS relaxes them once the danger has passed. the SNS causes your heart rate to increase, and your BP to increase, whereas the PNS causes them both to be reduced. Another benefit is the SNS inhibits digestion whereas the PNS allows the process to start again. it is sometimes referred to as the body’s rest and digestion system.

Question 10

explain the structure and function of neurons

Answer 10

neurons are cells that are specialized to carry neural information throughout the body. there are 3 types of neurons: sensory, relay, or motor. they typically consist of a cell body, Dendrites and an axon.

Question 11

the structure and function of neurons:
explain the function and structure of Dendrites

Answer 11

Dendrites at one end of the neuron receive signal from other neurons or sensory neurons. these are connected to the cell body, the control center. from the cell body the impulse is carried along the axon when it terminates at the axon terminal.
many neurons have an insulating layer (myelin sheath) which allows impulses to be transmitted more rapidly down the neuron.

Question 12

the structure and function of neurons: what is the function and structure of action potentials?

Answer 12

neurons must transmit information both within the neuron and from one neuron to the next. The dendrites receive information from sensory neurons or other neurons. this information passes down the cell body, once it has arrived at the axon it travels in an electrical signal called action potential.

Question 13

what are Sensory Neurons?

Answer 13

these carry nerve impulses from the sensory receptors e.g. receptors for vision, taste and touch to the spinal cord and the brain. these receptors are found in a number of locations: eyes, ears, tongue, and skin. Neurons convert information from these receptors to neural impulses. when these impulses reach the brain they are translated into sensations such as visual input, heat and pain.
not all sensory information travels as far as the brain. some neurons terminate at the spinal cord, this allows the reflex actions to occur quickly.

Question 14

what are Relay Neurons?

Answer 14

these neurons lie within the brain and the spinal cord. they arent sensory or motor but lie between sensory input and motor output. relay neurons allow sensory and motor neurons to communicate with each other.

Question 15

what are Motor Neurons?

Answer 15

these are the neurons located in the CNS that project their axons outside the CNS and directly or indirectly control muscles. Motor neurons form synapses with muscles and control their contractions. when stimulated, the neuron releases neurotransmitters that bind to receptors on the muscle and trigger a response which leads to muscle movement. when the axon of the motor neuron fires, the muscle contracts. the strength of the contraction bases on the rate of firing of the axons of motor neurons that control it. muscle relaxation is caused by inhibition of the motor neuron.

Question 16

what is Synaptic Transmission?

Answer 16

this is how neurons pass messages on from one neuron to the next.
once an action potential has arrived at the end of an axon it need to be transferred to another neuron or tissue. to do this, it must cross a gap between the presynaptic neuron to the postsynaptic neuron.
the physical gap is known as the synaptic gap. at the end of the axon are a number of sacs which are known as synaptic vesicles. these vesicles contain chemical messages that assist int he transfer of the action potential. as the action potential reaches these synaptic vesicles it causes them to release their contents: this process is called exocytosis.
the released neurotransmitters diffuse across the gap between the pre/post synaptic cell where it binds to specialized receptors on the surface of the cell. Once they have been activated, they produce an excitatory or inhibitory effect.
this whole process takes a fraction of a second. these effects are stopped due to a process of ‘re-uptake’. this is when neurotransmitters are taken up again by the presynaptic neuron, it is stored and available for later.
the quicker the presynaptic neuron take up the transmitters means the shorter effects for the post-synaptic neuron.

Question 17

what are neurotransmitters?

Answer 17

chemical messengers that carry signals across the synaptic gap. they can be described as excitatory or inhibitory.

Question 18

Neurotransmitters: excitatory

Answer 18

nor adrenaline and acetycholine are the nervous systems on switches. these increase the likelihood of an excitatory signal being sent to the post synaptic cell, and so are more likely to fire.
Excitatory neurotransmitters bind with post synaptic receptors which leads to an electrical change on the membrane of the cell = EPSP (excitatory post synaptic potential) which makes them fire

Question 19

Neurotransmitters: Inhibitory

Answer 19

serotonin and GABA are the switches off. they decrease the likelihood of a neuron firing. these calm the body and induce sleep. the inhibitory neurotransmitters bind with post synaptic receptor (IPSP) which means they are less likely to fire.
nerve cells receive EPSP and IPSP at the same time. the likelihood of a cell firing is therefore determined by adding up the excitatory and the inhibiting input. This calculation will determine whether the cell will fire.

Question 20

Neurotransmitters: how can the strength of EPSP be increased?

Answer 20

1, Spatial summation: large number of EPSP are generated at many different synapses on the same post synaptic neuron at the same time.
2. Temporal summation: large number of EPSPs are generated by the same synapse by a series of high frequency action potentials on a post synaptic neuron.

Question 21

MAJOR ENDOCRINE GLANDS:
Gland, hormone produced, and effect of hormone

Answer 21

• Pineal gland , produces melatonin , and affects reproductive development and daily physiological cycles.
• Pituitary gland , produces anti-diuretic hormone and gonadotrophins , controls growth of bones and muscles, increases transposition of water in kidneys, and controls development of ovaries and testes.
• thyroid gland , produces thyroxine , and controls the rate of metabolism
• adrenal gland , produces adrenaline , and prepares the body for emergencies such as increased heart rate, raises blood sugar levels
• pancreas , produces insulin and glucagon , it converts excess glucose into glycogen in liver and other way around
• ovaries , produce oestrogen and progesterone , and controls ovulation and secondary sexual characteristics, prepares the uterus living for receiving an embryo
• testes , produces testosterone , controls sperm production and secondary sexual characteristics

Question 22

what are Endocrine glands?

Answer 22

These produce and secrete hormones. These are chemical substances that regulate the activity of cells of organs. The major glands include pituitary, adrenal, and the reproductive organs. Each gland produces a different hormone. This system is regulated by feedback
1. Signal is sent from the hypothalamus to the pituitary gland telling it to release a hormone
2. Pituitary gland secretes a stimulating hormone into the blood stream
3. Hormone signals to the target gland to secrete its hormone
4. Levels of hormones rise in the blood stream
5. Hypothalamus then shuts down the secreting hormone
6. Pituitary gland shuts down production of the hormone
7. Stabilisation for hormones

Question 23

what are Hormones?

Answer 23

These are chemicals that circulate the blood stream and are carried into target sites. These hormones excite parts of the body. Even though hormones come into contact with a number of cells, they only have the ability to affect a number of target cells. These cells respond as they have a number of receptors for that hormone. When enough receptors sites are stimulated by the hormone this causes a physiological reaction on the target cells.
Timing of hormone release is vital for normal, functioning, too much or too little can cause dysfunction.

Question 24

what are Pituitary glands?

Answer 24

This gland produces hormones this then influences the release of hormones from other glands, thus regulating the body’s functions.
The pituitary is controlled by the hypothalamus. This part of the brain receivers information from main sources of the body about basic functioning. This helps the pituitary to regulate functioning. The pituitary produces hormones that travel in the blood stream to their target. These hormones then cause changes in physiological process or stimulate other glands to produce hormones.
High levels of hormones produced in other endocrine glands can stop the hypothalamus and pituitary prouducing more of their own hormones = negative feedback. This stops hormone levels rising too high.

Question 25

Hormones produced by the pituitary gland

Answer 25

The pituitary gland has two parts: anterior and posterior. These 2 parts release different hormones which target different parts of the body
ANTERIOR: produces ACTH which acts as a response to stress, which stimulates the adrenal gland to produce cortisol. It also produces LH (luteinising hormone) and FSH (follicle stimulating hormone). These stimulate the ovaries to produce oestrogen and progesterone in females, and in males they stimulate testosterone and sperm.
POSTERIOR: releases oxytocin which stimulates the contraction of the uterus during childbirth. Elabd et al (2014) stated research with mice shows the levels of oxytocin decline with and is essential for healthy maintenance and repair of the body.

Question 26

what are The adrenal glands?

Answer 26

The adrenal glands sit on top of the kidneys, it is seperated into two parts. The outer parts of each gland is the adrenal cortex and the inner area is the adrenal medulla. These areas have different functions. The main difference is that hormones in the adrenal cortex are necessary for life whereas the adrenal medulla is not.
ADRENAL CORTEX: produces cortisol which regulates and supports a variety of important body functions including cardiovascular and anti-inflammatory functions. Cortisol is produced as a response to stress. If the cortisol level is low, they will have low BP, poor immune functioning and an inability to deal with stress. The adrenal cortex also produces aldosterone which is responsible for maintaining blood volume and blood pressure.
ADRENAL MEDULLA: releases adrenaline and noradrenaline which produce the body for fight or flight. Adrenalin helps the body respond to a stressful situation. Noradrenaline constricts the blood vessels causing BP to increase.

Question 27

what is Fight or flight?

Answer 27

-Amygdala associates sensory signals with emotions such as fear and anger. It sends a distress signal to hypothalamus.
-SNS prepares body for rapid action
-PNS dampens the stress response when the threat is passed
-adrenal medulla releases adrenaline into the blood stream which leads to increased heart rate and release of blood sugar
-adrenal cortex releases stress hormones including cortisol
-the feedback system cortisol levels are monitored so that CRH & ACTH production is inhibited if cortisol levels are too high
-pituitary gland releases ACTH into the blood stream which goes to its target sites
- hypothalamus responds to continued threat and releases CRH into bloodstreams

Question 28

Fight or flight: describe the response to sudden stressors - acute

Answer 28

The SNS is triggered, which prepares the body for fight or flight. The SNS sends messages to the adrenal medulla which repsonds by releasing the hormone adrenaline into the blood stream. Adrenaline circulates the body and causes physiological changes e.g. HR increases, pushing blood to the muscles, BP increases, and breathing increases to take in as much oxygen as possible. Adrenaline causes the release of blood sugar and fats into the blood stream which supply energy to parts of the body associated with fight or flight.
When the threat has passes, the PNS dampens down the stress response. The PNS reduces the HR and BP, and starts digestion off again.

Question 29

Fight or flight: describe the response to chronic stressors

Answer 29

If the brain continues to perceive something as threatening, a second system starts. As the initial sure of adrenaline subsides, the hypothalamus activates the HPA axis.
H=Hypothalamus
The hypothalamus releases the chemical messenger CRH (corticotrophin-releasing hormone) this is released into the blood stream.
P=pituitary gland
CRH causes the pituitary gland to produce and release ACTH (adrencorticotrophic hormone), this is transported into the bloodstream to its target site, the adrenal gland.
A=adrenal cortex
ACTH stimulates the adrenal cortex to release stress related hormones such as cortisol. This gives the body a quick burst of energy and lowers sensitivity to pain. Other side effects can be negative such as impaired cognitive impairment and a lowered immune response.

Question 30

fight or flight: feedback

Answer 30

The system is efficient at regulating itself. The hypothalamus and the pituitary gland have special receptors that monitor cortisol levels. If these rise above normal levels they initiate a rise of CRH & ACTH, lowering cortisol levels

Question 31

Fight or flight: evaluation

Answer 31

• Tend and befriend: Taylor eat al 2000 suggested for females the stress response is characterised by tend and befriend rather than fight or flight. This involves them protecting themselves and their young (tend) and form alliances with other women (befriend). Women may have completely different coping systems for stress as their responses have evolved due to their role as a caregiver. Fleeing would out their offspring at risk. Women are thought to release oxytocin - inducing relaxation, reduce fearfulness and decrease the stress reponse.
  -fight or flight does not tell the whole story: Gray (1988) argues the first response is not fight or flight, but is to avoid confrontation. He suggests that before fight or flight, most animals and people freeze. This allows us to focus our attention and look for new information so we can deal with the threat in the best way possible.
  -A genetic basis to sex differences: Lee and Harley (2012) found genetic differences in men and women in fight or flight. The SRY gene found on the male Y chromosome promotes aggression, priming males with adrenaline. The absence of the SRY gene in women, together with oestrogen and oxytocin prevents this reaction in women.

Question 32

Localisation of function: definition

Answer 32

This is the idea that language, memory and hearing have specific locations in the brain.

Question 33

Localisation of function: motor and somatosensory areas

Answer 33

The motor cortex is responsible for voluntary movements, it is located in the frontal lobe, the precentral gyrus. Both hemispheres of the brain have a motor cortex, the left side controls the right side of the body. The regions are controlled next to each other: the action of the foot are next to the region that controls the leg.
Somatosensory cortex directs the sensory events. This is located in the parietal lobe, the post central gyrus. The post central gyrus processes information relating to touch. Using sensory information from the skin, the cortex produces sensations such as touch, pressure, temperature and then localises specific body regions, as with the motor cortex, the left side of the cortex controls the right side of the body and vice versa.

Question 34

Localisation of function: visual and auditory centres

Answer 34

Visual centres: the visual cortex is located in the occipital lobe l, however, visual processing usually begins in the retina where light enters and strikes the photoreceptors. Nerve impulses from the retina are transmitted to the brain via the optic nerve. Some nerve impulses travel to the areas involved in coordination and circadian rhythms, but the majority terminate in the thalamus that passes information to the visual cortex.
The visual cortex spans both hemispheres, the right hemisphere receives input the left visual field. The visual cortex contains several areas that process different types of visual information such as colour and shape.
Auditory centres: most of this area lies within the temporal lobes on both sides of the brain, the auditory cortex. The auditory pathways begin in the cochlea where sound is converted to nerve impulses this then travels to the auditory cortex. To the brain the brain stem decodes the duration and intensity of the sound. Then onto the thalamus which acts as a relay station that carries out further processing. The last stop is the cortex, the sound has been decoded at this stage, the cortex initiates an appropriate response.

Question 35

Localisation of function: language centres

Answer 35

Broca’s area: broca studied patient ‘Tan’ he could understand language but was unable to speak or write his communications down. Broca studied a further 8 patients who had similar disorders along with lesions to their left frontal hemisphere. Patients with similar damage but in the right hemisphere posed no problems. This led him to identify a language centres the posterior portion of the frontal lobe in the left hemisphere. However, this area also appears to work when we are conducting cognitive tasks, therefore we think it is divided into 2 areas: a language centre and a cognitive processing area.
Wernicke’s Area: this area is responsible for understanding language the posterior portion of the left temporal lobe. These patents could speak but were unable to understand language. Wernicke proposed language requires separate motor and sensory regions. The motor region Broca’s area is close to the control of the mouth, tongue and vocal cords. The sensory region Wernicke’s area id close to auditory and visual inputs.
There is a loop between the 2 areas: arcuate fasciculous
Broca’s area: production of language
Wernicke’s area: processing spoken language

Question 36

Localisation of function: evaluation

Answer 36

Challenges to localisation: not all researchers agree that cognitive functions are localised within the brain. A conflicting view (equipotentiality) theory Lashley 1930 believed that basic motor and sensory functions were localised, but higher mental functioning were not. He claimed intact areas of the cortex could take over responsibility for specific cognitive functions following injury. The effect of damage to the brain would be determined by the extent rather than the location of the damage.
Individual differences in language areas: Bavalier et al (1997) found that there were huge individual differences in brain activation during a silent reading task. They observed activity in the temporal lobes as well as left frontal, temporal, and occipital. Some studies have also found gender differences. Women have been found to have a larger Broca’s and Wernicke’s areas.
Language production might not just be confined to Broca’s area alone: Dronkers et al (2007) stated MRI findings have suggested other areas apart from Broca’s could contribute to impaired speech abilities. This suggests language and cognitive are far more complex than one specific area.

Question 37

Lateralisation and split brain research
Definition

Answer 37

The idea that different hemispheres have different specialisms date back to 1800s. Research was conducted to see the possible effects of split brain research, thus allowing psychologists to study each hemisphere separately.

Question 38

Lateralisation and split brain research:
Hemispheric lateralisation

Answer 38

Brain lateralisation refers to the fact that two halves of the brain are not exactly alike. Each hemisphere has specialisations e.g. the left hemisphere is dominant for language and speech whereas the right hemisphere excels at visual motor tasks. Brocas established famished to a specific part of the left hemisphere led to language deficit whereas damage to the same area in the right hemisphere did not have the same consequence.
The chance to explore the hemispheres when patients with severe epilepsy have their corpus callosum cut

Question 39

Lateralisation and split brain research: Lateralisation evaluation

Answer 39

Advantages of lateralisation: lateralisation is thought to increase neural processing activity. By using only one hemisphere for a task would leave the other hemisphere free to complete another function. However, very little evidence shows that lateralisation is advantageous to the brain. Rogers et al (2004) found that in chickens brains, lateralisation help when performing 2 tasks at once.
Lateralisation and immune system functioning: there are a number of advantages and disadvantages associated with lateralisation e.g. architects and mathematically gifted tend to have a superior right hemisphere. People with a superior left hemisphere are more likely to suffer from allergies and immune system issues. This suggests that the same genetic processes that lead to lateralisation may also affect the development of the immune system.
Lateralisation changes with age: lateralisation does not remain the same throughout your lifetime, it changes with ageing. Lateralisation in young people appears to turn bi-lateralisation in later life. Szaflarski (2006) language was found in the left hemisphere but after 25 years it decreased with each decade. It is thought this could be due to compensating with ageing.

Question 40

Lateralisation and split-brain research: split-brain research

Answer 40

Sperry and Gazzaniga’s research was the first to research split-brain research patients. To test the capabilities, they were able to send visual information to just one hemisphere, this is known as hemispheric lateralisation.
they used the fact that the left visual field is processed in the right hemisphere, and this area had no opportunity to pass information to the left hemispheree as the corpus callosum was cut.
PP’s were shown images to their left or right visual field. they were asked to make responses with either their left hand (right hemisphere) or right hand (left hemisphere) or verbally (left hemisphere) without being bale to see what their hands were doing.
with split-brain patients, a number of differences have been found
left = language
right = visual spatial
research suggests the connectivity between the regions is vital and as important as the different parts

Question 41

Lateralisation and split-brain research: split-brain research evaluation

Answer 41

Language may not be restricted to the left hemisphere: Gazzaniga (1998) suggests some of the early findings from research are no longer true. JW found the capability to speak from his right hemisphere he can speak about information that is presented to the left and right hemisphere.
Limitations of split-brain research: split-brain research is rarely carried out now, so there aren’t enough patients to create conclusions from. Andrews (2001) most studies use either 1 or 3 PPs therefore results are summarised from PPs who have severe physical disorders. therefore, there are generalisation issues.

Question 42

Plasticity and functional recovery of the brain: definition

Answer 42

Brain plasticity: the brains ability to change and adapt as a result of experience. This plays an important role in the brains development and behaviour. Previously, we associated learning with childhood whereas now we know learning takes place throughout our lifetime as we make neural pathways.
Functional recovery: moving functions from a damaged area to an undamaged area

Question 43

Plasticity and functional recovery of the brain:
Plasticity - result of life experience

Answer 43

One factor that can cause plasticity.
As people gain new life experiences new neural pathways develop stronger connections, whereas neurons that are rarely used die. By developing new hypothesis and pruning away weak ones, the brain is able to adapt to change, cognitive functioning can also decline with age this can also be attributed to changes in the brain.
Boyke et al (2008) found evidence for brain plasticity in 60 year olds who were taught a new skill, juggling. This increased the gray matter of their visual cortex, when they stopped practicing the changes reversed.

Question 44

Plasticity and functional recovery of the brain:
Plasticity - playing video games

Answer 44

Another factor that can cause plasicity.
Kuhn et al (2014) compared a control group with a video training group. This group were trained at least 30 mins a day for 3 months on Super Mario. There was a significant increase in grey matter in cortex, hippocampus, and cerebellum. These results were not seen in the control group, the researchers suggested that the game had produced new synaptic connections in the brain areas that were involved in spatial navigation, strategic planning, working memory and motor performance- skills essential for playing the game.

Question 45

Plasticity and functional recovery of the brain:
Plasticity - meditation

Answer 45

researchers working with Tibetan monks have demonstrated meditation can change the inner workings of the brain. Davidson et al (2004) compared 8 practitioners of Tibetan meditation with 10 student volunteers with no experience of medication. both groups were fitted with electrical sensors and were asked to meditate. those who were used to meditating produced more gamma waves. therefore, meditation changes the brain not just in the short term but also may cause permanent changes.

Question 46

Plasticity and functional recovery of the brain:
Plasticity - evaluation

Answer 46

Research support from animals: Kempermann et al (1998) investigated if an enriched environment could alter the number of neurons in the brain. rats who had a stimulating environment had an increased environment had an increased number of neurons in comparison to rats who were kept in basic conditions. there was a particular increase in the hippocampus - which creates new memories.
support from human studies: Maguire et al (2000) studied London taxi drivers to see if their spatial navigation altered their brains. the grey matter of taxi drivers was compared to the grey matter in control PPs. the posterior hippocampus in taxi drivers was significantly larger in taxi drivers.

Question 47

Plasticity and functional recovery of the brain:
functional recovery after trauma

Answer 47

in the 1960’s, researchers studied cases in which stroke victims were able to regain functioning. they discovered that when brain cells were destroyed or damaged as a result of a stroke, the brain re-wired itself over time so some level of functioning was regained. other parts of the brain appear to take over functions.

Question 48

Plasticity and functional recovery of the brain:
functional recovery after trauma - mechanisms for recovery

Answer 48

regeneration of the brain arises from the brain’s plasticity it changes both its structure and its function following trauma. it can do this one of 2 ways:
neural unmasking: there are dormant synapses in the brain. these exist anatomically but their function is blocked. normally, these synapses are ineffective as neural input is too low for them to fire. if a nearby area is damaged there would be an increased rate of firing, this can unmask or open these synapses. this opens connections to the areas of the brain that are not normally active, creating a lateral spread.
Stem Cells: these are specialised cells that can carry out different functions including the characteristics of nerve cells. some people think these cells implant into the brain and replace dying or dead cells. a second possibility is that they secrete growth factors that rescue injured cells, and a final possibility is that they link undamaged areas of the brain together.

Question 49

Plasticity and functional recovery of the brain:
functional recovery after trauma - evaluation

Answer 49

research from animal studies: Taijin et al (2013) assigned lab rats with brain trauma to one of two conditions. one gorup were injected with stem cells to the traumatised area, the second group recieved a solution inhected with no stem cells. after 3 months, the rats who were injected with the stem cells began to show neural cells in the damaged area. this was also accompanied by stem cells migrating to the injured side.
age difference with functional recovery: plasticity reduces with age. trauma to the brain after childhood is to develop compensatory strategies. some studies have shown that plasticity may be possible in adults but nowhere near as successfully as in children.
educational attainment and functional recovery: Schneider et al (2014) found that patients with the equivalent college education were 7 times more likely to bounce back after brain trauma than people who didn’t finish school. they carried out a retrospective study of 769 patients, 214 had achieved disability-free status within a year. of the 39% had 16 + years of education, 31% had 12-15 years of education, and 10% had 12 years of education. researchers through an ‘educational reserve’ could be neural adaption associated with educational attainment.

Question 50

Ways of studying the brain: post-mortem examinations

Answer 50

researchers may follow an individual when they are alive as they exhibit a particular form of brain damage. when they pass away, researchers look for abnormalities that may explain the behaviour.
Broca’s patient, Tan displayed speech problems when alive, when dead the patient displayed lesions in Broca’s area - speech production area.
HM’s post-mortem highlighted lesions in the hippocampus - an inability to store new memories.
reduced number of glial cells in the frontal cortex were associated with depression.

Question 51

Ways of studying the brain: post-mortem examinations - evaluation

Answer 51

• allows for detailed anatomical and neurochemical research. it allows deeper regions of the brain such as the hypothalamus and hippocampus.
• Harrison’s (2000) post-mortem studies have revealed a great deal about Schizophrenia: structural abnormalities and found changes in neurotransmitters.
• as people die at different stages of illness this can influence a post-mortem’s results as can drug treatments, age of death, and the length of time between death and post-mortem can all impact upon findings.
• retrospective therefore no follow-up is possible.

Question 52

Ways of studying the brain: scanning techniques - fMRI (Functioning Magnetic Resonance Imaging)

Answer 52

this measures changes in brain activity whilst a person is performing a task. it measures the changes in blood flow, which indicates neural activity. when an area of the brain becomes more active, there is an increased demand for 02. The brain responds to this extra demand by increasing blood flow, thus increasing 02. researchers can produce brain maps, which areas are associated with particular tasks.

Question 53

Ways of studying the brain: scanning techniques - fMRI (Functioning Magnetic Resonance Imaging) evaluation

Answer 53

• non-invasive and no harmful radiation is used.
• objective and reliable, especially for neural activity that cannot be documented verbally.
• it is not a direct measurement, it only records associated blood flow. therefore, it is not truly a quantitative method of metal activity.
• this method ignores the networked capabilities of the brain and assumes all tasks are localised to specific areas.

Question 54

Ways of studying the brain: scanning techniques - EEG (Electroencphalogram)

Answer 54

this measures the electrical activity of the brain. electrodes are placed on the scalp and detect small electrical charges, these are then also converted to graphs.
EEG can detect a range of disorders such as epilepsy or diagnose disorders that influence electrical activity such as Alzheimer’s. EEG readings of epilepsy show spikes of electrical activity. brain damage can show a slowing down of electrical activity.
the 4 basic patterns are alpha, beta, delta and theta waves:
alpha waves: awake but relaxed rhythmical
beta waves: low amplitude and fast frequency when aroused and awake. these are also found in REM sleep.
delta and theta waves: when sleeping

Question 55

Ways of studying the brain: scanning techniques - EEG (Electroencphalogram) evaluation

Answer 55

• real-time reading of the brain
• useful in clinical diagnosis
• EEG cannot investigate deeper regions of the brain. electrodes can be implanted into animals’ brains but this is deemed unethical
• it is possible to pinpoint the exact locations of electrical activity. therefore, it is impossible to tell if the activity is due to the test you are carrying out or if it’s due to general processing.

Question 56

Ways of studying the brain: scanning techniques - ERPs (Event Related Potentials)

Answer 56

these are very small voltage changes in the brain that are triggered by cognitive processing or tasks. these can be difficult to pick out amongst all other electrical activities. To establish a response to a target requires many presentations of the stimulus and these responses are averaged together. this should cancel out any other neural noise.
ERPs are divided into 2 categories:
- waves that occur within the first 100 milliseconds after presentation = sensory ERPs. these reflect an initial response to the physical characteristics of the stimulus.
- ERPs generated after the first 100 milliseconds reflect how you evaluate the stimulus, these are cognitive ERPs as they demonstrate information processing.

Question 57

Ways of studying the brain: scanning techniques - ERPs (Event Related Potentials) evaluation

Answer 57

• provides a continuous measure of processing, we can see how processing is affected by manipulation
• ERP can measure behaviour without needing a behavioural response
• ERPs are so small it is difficult to pick them out from other electrical activity. a number of trials are required to get any meaningful data
• Electrical activity within the brain is not picked up, similar to EEG only the neocortex is registered.

Question 58

Circadian rhythms: what is a circadian rhythm?

Answer 58

A circadian rhythm is changes to the biological rhythms that last 24 hours, such as the sleep/wake cycle. One example of biological changes is around 7.30pm, melatonin secretion begins.

Question 59

Circadian rhythms: what is an endogenous pacemaker and an exogenous zeitgeber?

Answer 59

EP: body’s internal clock
EZ: external cues e.g light that help regulate the internal biological clock.

Question 60

Circadian rhythms: Siffre

Answer 60

He lived underground to regulate his own circadian rhythm for 61 days with no external cues (exogenous zeitgebers). He came out on September 17th, but thought it was August 20th. This shows that endogenous pacemakers are most significant in determining the sleep/wake cycle.

Question 61

Circadian rhythms: Aschoff and Wever

Answer 61

A group of PPs stayed in a WW2 bunker for 4 weeks with no natural light (endogenous pacemakers). 1 PP saw their sleep/wake cycle extend to 29 hours, while all others stayed between 24/25 hours. This shows how exogenous zeitgebers are needed to regulate the sleep/ wake cycle.
The small sample size is unrepresentative and therefore has limited results. They only apply to those in the study.

Question 62

Circadian rhythms: Folklard et al

Answer 62

12 PPs lived in a cave for 3 weeks. They had a clock and when it read 11.45pm, they went to sleep, and when it read 7.45am, they woke up. The clock got sped up, so the day only lasted 22 hours, and PPs were unable to adjust to it.
This shows exogenous pacemakers are stronger influences on the sleep/wake cycle than exogenous zeitgebers as PPs were unable to shorting their cycles.
This gives psychologists a better understanding of behaviours that can occur because of disruptions to circadian rhythms. Shift work: experience reduced concentration around 6am which is when mistakes are most likely to occur. Shift workers are more likely to experience poor health (3x more likely to develop heart disease).

Question 63

Circadian rhythms: evaluation

Answer 63

Temperature may be more important than light: some psychologists believe temperature influences the system rather than light. The suprachiasmatic nucleus transforms information from light levels into neural levels that set the body’s temperature. Body temperature fluctuates on a 24 hour circadian rhythm. Very small variations in temperature can cause cells to become active or inactive.

Question 64

Ultradian and infradian rhythms: what is the difference between ultradian, circadian, and infradian rhythms? (ICU)

Answer 64

An ultradian rhythm lasts less than a day. For example, a 90 minute REM cycle.
A circadian rhythm lasts 24 hours. For example, sleep/wake cycle.
An infradian rhythm lasts longer than 24 hours. For example, womens’ menstrual cycle.

Question 65

Ultradian and infradian rhythms: what is an ultradian rhythm?

Answer 65

With sleep, another cycle exists. We go through 5 stages in an evening. We follow alternating REM and NREM - stages 1-4. The cycle repeats itself every 90-100, different stages have different durations. We travel through stages 1-4 then into REM and back to stage 1 etc.

Question 66

Ultradian and infradian rhythms: stages of sleep

Answer 66

Stage 1: 4-5% light sleep, muscle activity slows down, sometimes light muscle twitches.
Stage 2: 45-55% breathing and heart rate slows down, slight decrease in temperature.
Stage 3: 4-6% deep sleep begins, which produces slow delta waves
Stage 4: 12-15% very deep sleep, rhythmical breathing, limited muscle activity, delta waves.
Stage 5: 20-25% REM, brain waves speed up and dreaming begins. Muscles relax, heart rate increases, breathing rapid and shallow.

Question 67

Ultradian and infradian rhythms: monthly infradian rhythms

Answer 67

Menstrual cycles can vary between 23-36 days, but the average is 28 days. The cycle is regulated by by hormones which either promote ovulation or stimulate the uterus for fertilisation. Ovulation roughly refers roughly half way through the menstrual cycle when oestrogen levels peak usually lasts for 15-32 hours. After the ovulation phase, progesterone levels increase in preparation for the embryo in the uterus.
- however, there is no set length for the menstrual cycle, so individual differences are present here.

Question 68

Ultradian and infradian rhythms: annual infradian rhythms

Answer 68

There are seasonal variations in mood, SAD. Melatonin is secreted by the pineal gland at night. Longer nights in winter and lack of light lead to increased secretion which leads to SAD. Lamps can be used as exogenous zeitgebers to increase serotonin levels.

Question 69

Ultradian and infradian rhythms evaluation

Answer 69

Individual differences in sleep stages: Tucker et al suggests these differences are biologically determined and could even be genetic. Especially in stage 3/4, there were big individual differences.
The menstrual cycle - role of exogenous pacemakers: Russel conducted a study where daily sweat samples were taken from one group of one women, and rubbed onto the lips of a 2nd group. These groups were kept separate, but their cycles were synchronised. This suggests cycles are affected by pheromones. This therefore demonstrates that exposure to Exogenous zeitgebers does have an impact upon the infradian cycle.
Menstrual cycle: Reinberg conducted a case study on a woman who lived in a cave for 3 months with only a small torch. Her menstrual cycle shortened from 28 days to 25.7. Results show that a lack of light (exogenous zeitgebers) in the cage had an effect upon Mestrual cycle.
Sleep stages: Randy Gardner stayed awake for 264 hours. After, he slept for 15 hours - only recovered 25% of lost sleep. Results show flexibility of ultradian rhythms.

Question 70

endogenous pacemakers and exogenous zeitgebers: explain the role of the SCN

Answer 70

The most important endogenous pacemaker (or master clock) is the suprachiasmatic nucleus. It controls other biological rhythms, as it links to other areas of the brain responsible for sleep and arousal. The SCN also receives information about light levels (an exogenous zeitgeber) from the optic nerve

Question 71

endogenous pacemakers and exogenous zeitgebers: outline 2 studies to support the SCN

Answer 71

DeCoursey’s Chipmunks: Removed the SCN from 30 Chipmunks. She then leased them back into their natural habitat and observed. After 80 days, most of the lesioned chipmunks had been killed, due to them remaining awake during times when they should be asleep resulting in their death.
Morgan’s Hamsters: Gave lesioned brains to hamsters, resulting in a shorter sleep cycle at 20 hours. They adopted the same patterns as the lesioned hamsters.

Question 72

endogenous pacemakers and exogenous zeitgebers: explain the study into light - campbell and murphy

Answer 72

Shone a light onto the back of participants legs, altering their circadian rhythm, this may have been due to the SCN picking up alterations of blood chemistry.

Question 73

endogenous pacemakers and exogenous zeitgebers: what are social cues?

Answer 73

Social cues also act as exogenous zeitgebers, such as the timing of meals, work schedules, and exercise sessions. People can use social cues to compensate for a lack of natural light.

Question 74

endogenous pacemakers and exogenous zeitgebers: outline the role of melatonin

Answer 74

The SCN sends signals to the pineal gland, which leads to an increase in the production of melatonin at night, helping to induce sleep. The SCN and pineal glands work together as endogenous pacemakers; however, their activity is responsive to the external cue of light.

Question 75

endogenous pacemakers and exogenous zeitgebers: outline endogenous pacemakers evaluation

Answer 75

Folklard et al: 12 PPs lived in a cave for 3 weeks. They had a clock and when it read 11.45 pm, they went to sleep, and when it read 7.45 am, they woke up. The clock got sped up, so the day only lasted 22 hours, and PPs were unable to adjust to it. This shows endogenous pacemakers are stronger influences on the sleep/wake cycle than exogenous zeitgebers as PPs were unable to shorten their cycles.

Question 76

endogenous pacemakers and exogenous zeitgebers: outline exogenous zeitgebers evaluation

Answer 76

Siffre lived underground to regulate his circadian rhythm for 61 days without external cues (exogenous zeitgebers). He came out on September 17th, but he thought it was August 20th. This shows that exogenous zeitgebers are most significant in determining the sleep/wake cycle.