Biosychology

Question 1

Describe the role of each of the divisions of the nervous system (CNS, PNS, autonomic nervous system, somatic nervous system and sympathetic and parasympathetic branch)

Answer 1

CNS consists of the brain and spinal cord
- brain- receives and processes info, initiates responses
- spinal cord- conducts signals to and from brain, controls reflex actions

Peripheral- sends info to and from brain to CNS via neurons
Autonomous- controls involuntary movements, controls smooth muscles and glands
Symphatetic- fight or flight response
Parasympathetic- conserve and restore body energy when relaxed
Somatic- controls voluntary movements, controls skeletal muscles.

Question 2

Describe structure of a neuron

Answer 2

Dendrites- neurotransmitter receptors found. Chemical turn into electrical when neurotransmitter and receptor bind.
Cell body- (soma) contains nucleus and dna
Axon- sends nerve impulse down neuron and transmits msg to next neuron.
Myelin sheath- insulates axon and allows
Node of ranvier- allows electrical impulse to jump from one node to another
Terminal button- electrical messengers turned back to chemical via neurotransmitters

Question 3

Sensory neuron location function and structure

Answer 3

-location- the PNS in clusters known as the ganglia

function- send info from senses to brain. Receptors found in eyes, ears tongue, skin

Structure- they have long dendrites and short axons. (Cell body in the middle)

Question 4

Relay neuron location function and structure

Answer 4

Location- in the brain (CNS) and visual system

Function- they carry nerve impulses between neurons allowing sensory and motor to communicate. They analyse sensations from the neurons and decides how to respond

Structure- short dendrites short axons no myelin sheath

Question 5

Motor neuron

Answer 5

Cell bodies found in CNS but long axons found in PNS

• send info via long axons from the CNS through to effectors such as muscles or glands.
• they have short dentrites and long axons.

Question 6

Process of synaptic transmission

Answer 6

-Begins in pre synaptic neurone, action potential sent down the axon until it reaches the pre synaptic neuron
- neurotransmitters stored in vesicles in presynaptic neuron move across synaptic cleft
- they then bind to receptor sites on post synaptic neuron
- once enough neurotransmitters bind to receptor sites there’s 2 outcomes:
- next neuron ready to fire impulse depending on if the neurotransmitter has excitatory or inhibitory effect
- the neutransmitters are recycled back into the presynaptic neuron (reuptake)

Question 7

Neurotransmitters

Answer 7

Chemical messengers in the brain. They transmit info from one neuron to other so that a person can form an action or emotional response.

Question 8

Excitatory neurotransmitter

Answer 8

Eg adrenaline

• when excitatory neurotransmitter binds to receptors on post synaptic cell it becomes positively charged
• more likely to fire an impulse
• increases brain activity in CNS

Question 9

Inhibitory neurotransmitter

Answer 9

Eg seratonin

• when inhibitory neurotransmitter binds to receptors on post synaptic cell it becomes negatively charged
• less likely to fire an impulse
• decrease in brain activity

Question 10

Summation

Answer 10

• when inhibitory and excitatory influences are added together
• if overall charge negative (inhibitory) then less likely to fire impulse down post synaptic neuron
• if overall charge positive (excitatory) then more likely to fire impulse down post synaptic neuron

Question 11

Explain the function of the endocrine system

Answer 11

• chemical communication system within the bloodstream
• regulates activity of cells and organs in the body
• slower than nervous system however effects are more widespread and powerful
• chemical messengers are hormones which which are released by glands to regulate many bodily functions

Question 12

Hormone definition and 2 example

Answer 12

Chemical messagers which are released by glands within the endocrine system to regulate many bodily functions.

Eg melatonin for sleep wake cycle
Adrenaline for flight or fight response

Question 13

Define the term gland and include 2 examples with the hormone it secretes and what the hormone does

Answer 13

Gland- is an organ that releases a hormone which regulates functions in the body

Eg pineal gland which realeases melatonin which regulates the sleep wake cycle to make a person feel tired and ready to sleep

Eg adrenal gland releases adrenaline involved in the flight or fight response such as increased blood flow to transport o2 to brain.

Question 14

Explain how the symphatetic branch of the ANS leads to fight or flight response

Answer 14

-stressor identified by the hypothalamus and activated by pituitary gland which triggers activity in the sympathetic branch of the ANS
- adrenaline is released from adrenal medulla
- flight or digging response is produced, it prepares body for sudden action. This causes physiological actions such as increased heart rate high bp, respiration, reduced saliva. This is immediate and autonomic.
- the parasympathetic branch returns body back to normal when stressor is removed.

Question 15

Fight or flight response

Answer 15

it prepares body for sudden action. Causing psychological reactions such as increased heart rate, bp, reduced saliva, increased respiration. This is immediate and automatic.

Question 16

Parasympathetic branch

Answer 16

Returns body back to normal once the stressor has been removed. Therefore reduced heart rate , repiration.

Question 17

2 evaluation points for fight or flight response

Answer 17

• one issue is gender bias as it doesn’t not explain the stress response in females. Research has found that women are more likely to protect their offspring and form alliances with other women than to fight or run away. The fight or flight response assumes men and wome respond in same way to a threatening situation, therefore limiting the explanation.
• another issue is that it is not limited to two responses. As other responses could happen to danger such as avoiding confrontation or “freeze”. This suggests that the fight or flight response does not consider other factors such as though processes.

Question 18

Localisation of function definition

Answer 18

Specific areas of the brain are specialised for different function eg the motor cortex is responsible for voluntary movements.

Question 19

Motor cortex (both hemispheres)

Answer 19

-Controls voluntary movements
- damage can cause loss of control over fine movements or paralysis.

Question 20

Broca’s area (left hemisphere)

Answer 20

• production of spoken and written language
• damage to area can produce Brocas aphasia which is slow speech and lack fluency.

Question 21

Wernickes area (left hemisphere)

Answer 21

• understanding of language
• damage to this area causes wernicks aphasia- cannot understand spoken language or meaningless speech

Question 22

Visual cortex (both hemispheres)

Answer 22

• received info from eyes and processes colour and shape
  RVF- LH. LVF- RH
• damage leads to blindness, hallucinations and inability to see colour

Question 23

Somatosensory cortex (both hemispheres)

Answer 23

Processes info from senses in the skin, including touch, pressure, pain and temp in the body

• damage to area could lead to problems with perceiving touch, failure to recognise object by touch.

Question 24

Explain the difference between brocas and wernicks area

Answer 24

Broca’s area involves the production of spoken and written language whereas wernicks area is the understanding of language.

Question 25

3 evaluation points for localisation of function

Answer 25

RTS was by Broca. He did a case study on a man who was unable to speak apart from one word “tan” even though he could understand language. A post mortem showed damage to one area in the left hemisphere which is now named the Broca’s area. This shows that language production is localised to one specific brain area.

RTC comes from a case study done on patient EB. He suffered from brain damage which resulted in the removal of his left hemisphere. After some time he was able to regain some of his language ability. Therefore it suggest that his language centres may not be completely localised to the left. It shows that the language must be in more areas than just left hemisphere suggesting a holistic explanation of brain functioning is more appropriate than localisation of function

However both these studies lack population validity. Can’t generalise findings to wider population as these are unique case studies where brain damage may have effected the way in which brain functions. Therefore suggesting that more research is needed with more diverse samples before firm conclusions on the localisation of language areas.

Question 26

Hemispheric lateralisation ao1

Answer 26

The idea that the left and right hemisphere of the brain are responsible for different functions. The 2 hemispheres have diff functions and told. The left hemisphere is responsible for language. The 2 main language centres, the Broca’s area which is responsible for speech production and the wernicks area which is responsible for understanding of language. The right hemisphere is responsible for recognition of faces, places, objects and creativity. the brain has contra lateral wiring. The left hemisphere receives info from the RVF and controls the right side of the body. Whereas the right hemisphere receives info from LVF and controls the left side of the body.

Question 27

3 evaluation points for hemispheric lateralisation

Answer 27

RTS hemispheric lateralisation comes from speery. He conducted a study using split brain patients who had their corpus collosum severed. When presented with an object in their right visual field they were able to name it verbally. However when presented in the left visual field they could only point and identify the object. Therefore this supports that the brain is lateralised and suggests that the left and right hemispheres have diff functions such as the left hemisphere responsible for language abilities. Therefor wsplit brain research supports the theory of hemispheric lateralisation.

RTC comes from a case study on patient EB. He suffered from brain damage which resulted in the removal of his left hemisphere. After a while he was able to regain some of his language abilities. This wouldn’t have been possible the brain was completely lateralised. Therefor ethos shows that the language centres must be in more areas of the brain than just the left hemisphere going against the lateralisation of function theory.

However a weakness of this study is that it has low pop validity and may not be appropriate to generalise findings to wider population. The case study is unique where brain damage may have affected the way in which the brain functions and some ppl may be able to process language in right hemisphere. Therefore suggesting that more research is needed with more diverse samples before firm conclusion on the lateralisation of function.

Question 28

Define what is meant by split brain and when this surgery is performed

Answer 28

Split brain patients have surgery to treat epilepsy to cut the area that connects the two hemispheres of the brain (corpus collosum).

Question 29

Outline split brain research study

Answer 29

• to investigate the effects of severing the connection between the two hemispheres of the brain on functioning
• natural experiment, studying 11 ppt who had their corpus collosum severed
• pptts sat infront of a screen whilst fixating their face on the spot on the screen. There were presented an image to either the right or left visual field for 1/10 of a second so that there’s no time for them to switch focus between the fields. Objects seen in the right visual field could be named verbally and in writing as it would be processed by the language centres on the left side of the brain. Whereas the objects presents on the left visual field could be only identified through pointing but cannot be named.
• conclusion: the two hemispheres have diff abilities and functions but only left is able to produce language. The right hemisphere can recall and identify info but cannot verbalise.

Question 30

3 evaluation points for split brain research

Answer 30

strength is that it uses scientific methods. This is because it is based on objective and empirical techniques such and controlled lab setting . They are used to identify which hemisphere is responsible for which task. For eg the split brain patients were only able to say verbally what they saw when image presented to right visual field which suggests the left hemisphere is activated (language). This increases the overall internal validity of hemispheric lateralisation therefore raising psychology’s scientific status.

Research to contradict comes from case study on patient EB. Who suffered from Brain damage resulting in the removal of his left hemisphere. After a while he was able to regain some of his language abilities. This wouldn’t be possible if the brain had been completely lateralised. Therefore showing that language centres must be in more areas of the brain, going against lateralisation of function

A weakness is that it has low population validity. It is difficult to generalise to wider population as the case study is unique and the brain damage could affect the way the brains function. Therefore suggesting that the research needs more diverse samples before firm conclusions on the lateralisation of function

Question 31

Explain how holistic theory differs from localisation lateralisation

Question 32

Define plasticity and explain what is meant by synaptic pruning

Answer 32

Plasticity- the Brains ability to change and adapt it’s structures and processes as a consequence of experience and new learning

Synaptic pruning. During infancy the brain experiences a rapid growth in synaptic connections. The connections not used regularly are deleted and the ones that are used are strengthened.

Question 33

Outline an evaluation of plasticity

Answer 33

RTS plasticity was done by maguire et al. He studied the brains of London taxi drivers. It was found that those who had been taxi driver for long time had a greater volume of grey matter in areas responsible for spatial and navigation skills in contrast to those who had less experience. Therefore this supports plasticity as it suggest their brain structures altered due to experience and more knowledge of the road.

Question 34

Functional recovery

Answer 34

• recovery of abilities or mental processes (language and movement) that have been affected by brain damage or diseases.
• the brain is able to rewrite itself and form new synaptic connections close to damaged areas of the brain.

Question 35

2 methods of recovery

Answer 35

Axonal sprouting
- the growth of new nerve endings which connect to other undamaged nerve cells to form new neural pathways.

Recruitment of homologous areas
- when other areas of the brain take control over a damaged area of the brain and take the role eg if Broca’s area in LH was damaged the right side would take over.

Question 36

What affects recovery after trauma?

Answer 36

Perservance- recovery takes great amount of effort. Research has shown some ppl may appear to lose function however it may be as the person is not trying as they believe they are unrecoverable.

Gender- some research shown females are more likely to recover than males

age- research shown that younger ppl more likely to recover then old 40+. As in old people there is a detoriating of the brain which can affect speed of recovery

Stress and alcohol- recovery requires great deal of effort and stress and alcohol can make it difficult.

Question 37

3 evaluation points for plasticity and functional recovery

Answer 37

RTS comes from case study on patient EB. He suffered from brain damage resulting in removal of his left hemisphere. After a while he was able to regain some of his language abilities. This would not have been possible if his brain was completely lateralised. This suggests he has experienced recruitment of homologous areas as other parts of the brain has adapted to produce language even when the left hemisphere is not present. Therefore supporting the idea of plasticity and functional recovery

Weakness is that it lacks population validity. A case study cannot generalise to wider population. As it is a unique study where brain damage could have caused unique changes that may have influenced plasticity and functional recovery. Therefore lowering the external validity.

Strength is that it has practical applications. Axonal sprouting led to development of neurorehabilitation

Question 38

fMRI as way of studying the brain and 2 evaluation points

Answer 38

• used to detect levels of o2 in blood
• specific areas of the brain
• the more active the brain is more levels of o2 and increas in blood flow
• produces a 3d image

It is more safer and non-invasive technique as it does not use radiation. Therefore it is a more appropriate technique.

It has a higher spatial resolution than EEG and ERP. This allows it to take cleared images of specific brain areas with detail. However it has a poorer temporal resolution as there is a 0.5 sec time delay between image on screen.

Question 39

EEG + 2 evaluation

Answer 39

• electrodes places on scalp
• to detect electrical changes in activity (detect sleep patterns)
• graphed over a period of time to see general brain activity

High temporal resolution catches brain activity in real time, more accurate measure of brain

Low spatial resolution. Measures general brain activity can’t measure specific areas.

Question 40

ERP + 2 evaluation

Answer 40

• electrodes placed on scalp
• measures specific brain activity
• stimulus presented to individual and brain activity is measured same way as EEG

High temporal resolution. Can measure brain activity in milliseconds and in real time. However it has low spatial resolution can only detect general brain activity.

Hard to obtain meaningful data as it can be affected by external factors such as background noise.

Question 41

post mortem

Answer 41

Brain of a dead person is examined and dissected to see structures
Brain is compared to normal healthy brain
Used on ppl who have rare disorders

Only invasive way to study brain more detailed, study deeper

Hard to establish cause and effect due to confounding variables

Question 42

Circadian rhythms

Answer 42

a biological Rhythm that lasts 24hrs such as the sleep wake cycle

Question 43

Outline the sleep wake cycle as a circadian rhythm

Answer 43

-controlled by the master endogenous pacemaker the suprachaismatic nucleus found in the hypothalamus
- our eyes notice change in light as it gets dark and less light received by the retina
- this sends info to SCN and stimulates the pineal gland to release melatonin which promotes sleep.
- when eyes detect light (EZ) the SCN is reset and maintains sleep wake cycle to be in sync with the world.

Question 44

3 evaluation points for circadian rhythm

Answer 44

RTS comes from siffre. He isolated himself in a cave for 6 months where his biological clock wasn’t disturbed by exogenous zeitgeibers such as clock or natural light. It was found that within 2 days he developed a 25 hr cycle and continued to fall asleep and wake up on a regular cycle. Therefore this supports the circadian rhythm and that it is controlled by the edogenous pacemaker SCN.

However a weakness is that it is a case study so there is low population validity. It may not be appropriate to generalise findings due to individual differences in sleep wake cycle and circadian rhythms eg some may be slower and easily affected by EG. Therefore lowering the external validity of the research.

RTS comes from Wever who’s replicated the study in an underground bunker 400 times with 447 ppt. It was found that if a person was left to be running with the circadian rhythm it would follow a 25hr cycle. This supports siffre finding on endogenous factors maintaining circadian rhythm to around 24hr cycle. Research has good reliability.

Question 45

Infradian rhythm

Answer 45

Biological rhythm that lasts longer than 24hrs such as menstrual cycle

Question 46

Outline menstrual cycle as infradian rhythm

Answer 46

• endogenous system that lasts 28-35 days
• womb lining is shed
• in the brain the pituitary gland releases FSH which activates release of oestrogen
• increase in oestrogen leads to increase in LH which promotes release of an egg
• oestrogen develops lining of womb and progesterone held it grow thicker ready for pregnancy
• if pregnancy doesn’t occur then egg is absorbed into body
• cycle begins again
• can be affected by stress and phermomones

Question 47

3 evaluation points for infradian rhythm

Answer 47

• RTC menstrual cycle which is an endogenous system was conducted by Russel. They asked a sample of women to wear cotton pad under their arm. These pads were then rubbed on upper lip of 5 sexually inactive women repeated daily for 5 months. It was found that 4 out of 5 women synchronised their menstrual cycles within one day of the donor. Therefore suggesting that the menstrual cycle can also be affected by exogenous factors (pheromones) as well as being maintained by endogenous system.

Russell’s research had low control over extraneous variables as it was a field experiment.it took part in their natural environment where other exogenous factors such as light, diet and stress could affect the infradian rhythm. Therefore it’s difficult to establish cause and effect between influence of pheromones in maintaining infradian rhythm. This weakens the extent of this research to contradict.

Question 48

Ultradian rhythm

Answer 48

Biological rhythm that lasts under 24hrs such as the stages of sleep

Question 49

Outline stages of sleep as ultradian rhythm

Answer 49

Lasts around 90mins and has 5 stages of sleep

Stage 1 and 2 (NREM) - person may be easily woken, alpha waves. Stage 2 alpha waves continue but with random changes in pattern (sleep spindles). Have high frequency.

Stage 3 and 4 (NREM) - known as feel sleep, waves are delta with low frequency and high amplitude

Stage 5 (REM) - body is paralysed , theta waves. Brain activity resembles awake brain. Dreams often occur in this stage

Question 50

3 evaluation for ultradian rhythm

Answer 50

strength of research investigating ultradian rhythms is that it has practical applications in understanding age-related changes in sleep. The knowledge that growth hormone is produced during stage 4 of sleep (slow wave sleep) has been associated with sleep deficit in old age as research has found older people experience less stage 4 sleep. As a result of this research, medication and relaxation techniques have been developed to increase stage 4 sleep in older accidents individuals and therefore, prevent some issues associated with old age such as reduced alertness. Therefore, research investigating ultradian rhythms is an important part of applied psychology.

Further strength is that it uses scientific methods . This is because it uses objective and empirical techniques such as EEG to measure brain activity and controlled lab setting. Measure activity of brain though 5 stages of sleep excluding extraneous variables (light, noise). Therefore increases internal validity.

• low ecological validity research artificial setting may not reflect genuine sleep as they’re attached to electrodes. Difficult to generalise findings to real life