biopsychology

Question 1

divisions of the nervous system

Answer 1

• human nervous system divided into the peripheral nervous system and the central nervous system. the peripheral nervous system is subdivided into the autonomic and somatic nervous system. the autonomics system is divided into the sympathetic and parasympathetic and the central into the brain and spinal chord.

Question 2

the central nervous system

Answer 2

• the brain= centre of all conscious awareness. the brains outer layer, the cerebral cortex, is highly developed in humans and what distinguishes our higher mental functions from those of animals. divided into two hemispheres,
  -the spinal cord is an extension of the brain. responsible for reflex actions.

Question 3

the peripheral nervous system

Answer 3

• transmits messages via neurons to and from the CNS.
• the autonomic nervous stystem- governs vital functions in the body such as breathing,heart rate,digestion,sexual arousal and stress response.
  -somatic nervous is system- controls muscle movements and receives information from sensory receptors

Question 4

The endocrine system

Answer 4

• Works alongside the nervous system. Acts more slowly. Instructs glands to release hormones directly into the bloodstream. These hormones are carried towards target organs in the body.

Question 5

Difference between the endocrine system and the nervous system

Answer 5

• the endocrine system used chemical messages whereas the nervous system uses electrical impulses
• endocrine system has long-lasting effects and the nervous system is short lived
• the endocrine system takes to get to target organ whereas the nervous system is quicker

Question 6

Sympathetic adrenal medulary

Answer 6

• when a stressor is perceived the hypothalamus triggers the sympathetic nervous system.
• The ANS changes from it’s usual resting state-the parasympathetic
• adrenaline and noradrenaline is released from the adrenal medulla into the blood stream resulting in physical arousal needed for fight or flight

Question 7

Sympathetic state

Answer 7

• increase heart rate
• increase breathing rate
• dilates pupils
• inhibits digestion
  -inhibits salivary production
• increase blood pressure
• muscle activity

Question 8

Parasympathetic state

Answer 8

• decrease heart rate
  -decrease breathing rate
• constrict pupils
  -stimulates digestion
• stimulates saliva production

Question 9

Adrenal cortex pathway

Answer 9

-When there is a stressor.
- The adrenal cortex is activated by the hypothalamus via the pituitary gland.
- ACTH( adrenocorticotrophic) stimulates the adrenal cortex. Releases cortisol and glucocorticoids

Question 10

The structure of the neurone

Answer 10

• The cell body containing the nucleus
  -branch-like structure called dendrites protrudes from the cell body
• the axon carries the impulses away from the cell body down the length of the neuron.
• the axon is covered in layers of myelin sheath that protects the axon and speeds up electrical transmission
• Myelin sheath has gaps called nodes of ranvier. Speeds up transmission of the impulse by forcing it to ‘jump’ across gaps along the axon.
• end of the axon are terminal buttons that communicate with the next neurone in the chain across the synapse

Question 11

How do neurons communicate within neurons

Answer 11

Electrical impulses

Question 12

How do neurons communicate between neurons

Answer 12

Chemical transmission across the synapses

Question 13

Electrical transmission

Answer 13

• when a neuron is in its resting state the inside is negatively charged compared to the outside. When activated by a stimulus.the insides becomes positively charged for a split second causing an action potential to occur. Creates an electrical impulse that travels down the axon towards the end of the neuron.
• causes vesicles to fuse with the presynaptic membrane

Question 14

Synaptic transmission

Answer 14

When an electrical impulse reaches the presynaptic terminal it triggers the release of neurotransmitters from synaptic vesicles. Once the neurotransmitter crosses the synapse it is taken up by the post synaptic receptor site.where the chemical message is converted back into a electrical impulse.

Question 15

Reflex arc

Answer 15

• a stimulus is detected by sense organs in the peripheral nervous system
• coveys message along a sensory neuron
• message reaches the central nervous system where it connects with a relay neurone.
• transfers messages to a motor neuron
• ## carries messages to an effective such as muscles

Question 16

Excitation and inhibition

Answer 16

• neurotransmitter have either a excitatory or inhibitory effect on neighbouring neutrons. If inhibitory the neighbouring neuron becomes more negatively charge therefore is less likely to fire.e.g. Serotonin. If excitatory the positive charge of the neighbouring neuron is increased making it more likely to fire

Question 17

Summation

Answer 17

• the exhibitory and inhibitory influences are summed. If the net effect on the postsynaptic neuron is inhibitory then the postsynaptic neuron is less likely to fire. If the next effect is excitatory it is more likely to fire:

Question 18

localisation of functions of the brain

Answer 18

• Before the 19th century scientists supported the holistic theory that all parts of the brain was involved in processing thought and action.
  -Broca and Wernickes argued for localisation of function = different parts of the brain perform different functions
• if the certain area of the brain is damaged the function associated will also be affected.
• laterisation= activity on the left hand side of the body is controlled by the right hemisphere.
• activity on the right hand side is controlled by the lrft hemisphere

Question 19

structure of brain

Answer 19

• the cortex of both hemispheres is ub-divided into 4 lobes. frontal,parietal,occipital,temporal
  -at the back of the frontal lobe= motor cortex= controls voluntary movements on opposite sides of the brain. Damage= loss in control of movement
• front of parietal lobes is the somatosensory = where sensory information from the skin e.g. heat is represented. Areas where there is a higher amount of somatosensory area are more sensitive
• occipital lobe= the visual area=e.g. damage to the left hemisphere can produced blindness in part of the right visual field in both eyes
• temporal lobe= auditory area=damage may produce partial hearing loss

-left side of the brain is responsible for language. Broca’s area in the left frontal lobe is responsible for speech production and the wernickes area is responsible for language comprehension

Question 20

Evaluation of localisation of functions of the brain

Answer 20

• functional recovery is a limitation= undamaged areas of the brain can take over the functions of damaged areas of the brain suggesting the brain works together
• the brain is able to rewords and reorganise itself to fork new synaptic connections close to the area of damage.
• Karl lashley= removed areas of the brain in rats who were learning a maze. The process of learning appeared to require every sort of the brain suggesting learning is too complex to be localised and requires the whole brain
• evidence from aphasia studies= evidence for Broca’s and wernickes area in language production and understanding comes from the discovery that damage to different areas results in different aphasia.
  -Broca’s area= impaired ability to produce langauage from damage to Broca’s area
• wernickes area = impaired ability to understand language from damage to wernickes area

-phineas gage case study supports. He was preparing to blast a section of rocks with explosive to create a railway line. Gage dropped his tamping ion into the rock during the process causing an explosion which resulted in a metre length pole through his left cheek. Lost a lot of his left frontal lobe. He survived but became a short-tempered, agressive,rude person. Suggesting the frontal lobe may be responsible for regulating mood.

Question 21

Brain plasticity

Answer 21

• the brains tendency to change and adapt as a result of experience and new learning
• seen as when we age, rarely used neural connections developed at infancy are deleted and frequently used connections are stregthened( synaptic pruning)

Question 22

Research into plasticity

Answer 22

• magurie et al (2000) found significantly more volume of grey matter in the posterior hippocampus of London taxi drivers than in a matched control group. This part of the brain is associated with the development of spacial and navigational skills in humans and other animals. As part of training London drivers take ‘ the knowledge’ test which assesses their recall of streets and possible routes. It appears the result of learning experience alters the structure of taxi drivers brains. The longer they had been in the job the more pronounced the structural difference was.
• draganski et al (2006) imager the brains of medical students before and after exams and found learning- induced changes in the posterior hippocampus and the parietal cortex thought to be as a result of exams.
• Michelli et al(2004) found a larger parietal cortex in the brains of people who were bilingual compared to matched monolingual controls.

Question 23

Functional recovery

Answer 23

• form of plasticity. After damage through trauma unaffected areas of the brain are often able to adapt to compensate for the areas that are damaged
• healthy brain areas may take over the functions of those areas that are damaged,destroyed or missing.
• ## the brain is able to rewire and reorganise itself by forming new synaptic connections close to the area of damage and secondary neural pathways are activated to carry out certain neural functions

Question 24

Evaluation of plasticity and functional recovery

Answer 24

• practical application= neurorehabilitation= following illness or injury spontaneous recovery tends to slow down after a number of weeks so forms of physical therapy may be required to maintain improvements in functioning.
  e.g. after a stokes techniques may include movement therapy and electrical stimulation of the brain to counter the deflicts in motor and cognitive functioning. Shows that although the brain may have the capacity to fix itself to a point this process requires further intervention if it’s to be completely successful
  -recovery reduces with age. Therefore doctors must access wherever a person is likely to recover based on age
• lots of research m= Draganski et al and mechelli et al (2004)
• may be negative plasticity. Can have maladaptive behavioural consequences. E.g. prolonged drug use, had been short to result in poorer cognitive functioning as well as an increased risk of dementia in later life. Also 60-80% of amputees have been known to develop phantom limb syndrome- the continued experience of sensations in the missing limb as if it was still there. Due to cortical reorganisation in the somatosensory cortex occurring as a result of limb loss.
• educational attainment= may influence how well at the brain functionally adopts after injury = study discovered more time in education the greater their chance of a disability-free recovery (DFR)= 2/5 patients who achieved DFR had more than 16 year’s education compared to about 10% of patients who had less than 12 years

Question 25

split brain research

Answer 25

-Sperry’s (1968) study involved patients would had a commissurotomy operation therefore there was no communication between the two hemispheres.
-the general procedure involved showing an image or word to the patients right visual field (processed by the left hemisphere) and the same, or different image is projected to the left visual field.
-they found when an object was shown to the patients right visual field the patient could easily describe what was seen but when shown to the left visual field they often reported nothing was there. this is because of the lack of language centres in the right visual field
- However,in the left visual field they were able to select a matching object from a grab-bag of different objects using their left hand that associated with the o9bject presented.
-when two words where shown simultaneously one on either side of the visual fields they could say the object in their right visual field and could pick up the object in their left visual field
- the right hemisphere also appeared dominant in terms of matching faces.(left visual field)

Question 26

evaluation of split brain research

Answer 26

-It is assumed that the main advantage of brain lateralisation is that it increases neural processing capacity (the ability to perform multiple tasks simultaneously). Rogers et al. (2004) found that in a domestic chicken, brain lateralisation is associated with an enhanced ability to perform two tasks simultaneously (finding food and being vigilant for predators). Using only one hemisphere to engage in a task leaves the other hemisphere free to engage in other functions. This provides evidence for the advantages of brain lateralisation and demonstrates how it can enhance brain efficiency in cognitive tasks. However research was carried out on animals =lack of generalisability

-much of the research into lateralisation is flawed because the split-brain procedure is rarely carried out now, meaning patients are difficult to come by. Such studies often include very few participants, and often the research takes an idiographic approach. =lack of genralisability

-it could be argued that language may not be restricted to the left hemisphere. Turk et al. (2002) discovered a patient who suffered damage to the left hemisphere but developed the capacity to speak in the right hemisphere, eventually leading to the ability to speak about the information presented to either side of the brain. This suggests that perhaps lateralisation is not fixed and that the brain can adapt following damage to certain areas.

-experiments used highly standardized procedures. participants were given a fixation point to stare at. the image presented would be flashed up for one-tenth of a second,meaning the split-brain patient would not have had time to move their eye across the image and so spread the info across both sides of the visual field. this allowed Sperry to vary aspects of the basic procedure and ensured that only one hemisphere was receiving the information at the time. thus he developed a well- controlled and useful procedure

Question 27

FMRI’S

Answer 27

detect the changes in blood oxygenation and flow that occurs as a result of brain activity to specific parts of the brain. more activate brain area= consumes more oxygen and more blood flow is directed to the active area. three D images showing which part of the brain is active is produced. useful in understanding localisation of the brain

-have high spacial resolution and is non-invasive
-expensive compared to others and can only capture clear image if person is very still. has low temporal spacial resolution as has a five second lag time behind image on screen and initial firing of neuronal activity

Question 28

EEG’s

Answer 28

• measures electrical activity within the brain via electrodes that are fixed to an individual scalp using a skull cap. used as a diagnostic tool as abnormal patterns may indicate neurological abnormalities

-high temporal resolution and useful in the diagnosis of epilepsy and the stages involved in sleep
-not useful for pinpointing the exact source of neural activity

Question 29

ERPs

Answer 29

-use electrodes that are attached to the scalp, as with EEG. However, the key difference is that a stimulus is presented to a participant (for example a picture/sound) and the researcher looks for activity related to that stimulus. whereas EEGs look for general activity

-good temporal resolutions. can pinpoint where activity is occurring
-in order to establish pure findings background noise and extraneous materials have to be eliminate which is not easy to achieve
- low spatial resolution

Question 30

post-morten examinations

Answer 30

-patients brain is analysed after their death. likely those who have a rare condition.
-damage to the brain may be a result of decay. ethical issues= patients may have been unable to provide informed consent

Question 31

Circadian rhythm

Answer 31

• lasts around 24 hours e.g. the sleep wake cycle which dictates when animals and humans should be awake

Question 32

Siffres cave study

Answer 32

-self-styled caveman.
-spent several extended period underground to study the effects on his own biological rhythms
-deprived himself from natural light and sound but had access to adequate food and drink
-When he returned from an underground stay he believed to be a month earlier than it was
and cycle extended to twenty five hours
-This suggests that his 24-hour sleep-wake cycle was increased by the lack of external cues, making him believe one day was longer than it was, and leading to his thinking that fewer days had passed.

Question 33

Aschoff and Wever (1976)

Answer 33

• convinced a group of participants to spend four weeks in a WWII bunker deprived from natural light. All except for ones sleep wake cycle extended between twenty four and twenty five hours
• both siffre and this suggests the sleep wake cycle is longer than 24hours but is entrained by exogenous zeitbegers

Question 34

Evaluation of circadian rhythms

Answer 34

• case studies use small group participants or individuals. Lack generalisation. Siffre at age 60 cave study observed his internal clock ticked much slower showing even when the same person is involved there are factors which may prevent general conclusions being drawn.

-practical application to shift workers.
Has an economic implication in terms of learning how to best manage worker productivity.
-it’s found nightshift workers experience a reduced concentration around 6 in the morning meaning mistakes and accidents are more likely. Research have Also suggest a relationship between shift work and poor health: shift workers 3x more likely to develop heart disease due to the disruption and poor sleep during the day.

• practical application in drug treatment
• research has revealed peak times during the day or night when drugs are likely to be at their most effective. Led to development in guidelines to do with timings of drug dosage for medications e.g. anti cancer

-ideas are biologically deterministic as they assume hormones are the only cause of changes in circadian rhythms. Evidence suggests meal times and travelling are some of the factors which can cause changes. Differences in time zones mean hunger and tiredness occurs out of routinewith those local, suggesting the influence of light is subdued. Thus, biology is a limited explanation for changes in rhythms, and other variables should be considered to better understand how they work.

Question 35

Infraradian rhythm

Answer 35

occurring in periods or cycles of more than 24 hours

Question 36

Ultradian

Answer 36

• more than one cycle in 24 hours

Question 37

Example of infradian rhythms cycles and a evaluation

Answer 37

• the menstrual cycle which is typically 28days
  explain
• research study by mcClintok studies 29 women with a history of irregular periods. Sample of pheromones were gathered from 9 of the women at different stages of their menstrual cycle via a cotton pad placed in their armpit. After freezing and treating with alcohol the pads were rubbed on the top lip of the other participants. Day one, pads from start of the menstrual cycle applied and so in. It was found 68% experienced changes to their cycle bringing them closer to theirs odour donar. This suggest exogenous factors can influence out endogenous system.

Question 38

Example of ultradian rhythms

Answer 38

• stages of sleeps . Psychologist used EEG’s to identify 5 stages of sleep
• stage 1 and 2 = brain waves become slower the deeper the sleep. Light sleep so person easily woken
  -stages 3 and 4= involves delta waves which have a greater amplitude. Difficult to wake somebody up
  -stage 5, REM sleep = body is paralysed yet brain activity speeds up to resemble a awake brain. REM= rapid eye movement. Fast jerker activity of the eyes under eyelids correlated with dreaming

Question 39

Evaluation of intraradian cycles and ultraradian

Answer 39

• menstrual synchrony= evolutionary value
• may have been advantageous for females to menstruate together so fall pregnant around the same Time so new-borns could be cared for collectively within a social group increasing chance of offspring surviving.
• however validity of this has been questioned. Jeffrey Schank (2004) argued if too many women were cycling together = competition for highest quality males lowering the fitness of potential offspring. From thus point of view, avoidance of synchrony would be seen as the most adaptive evolutionary strategy.

-Seasonal affective disorders (SAD)
- depressive disorder. Symptoms such as lowered mood are triggered in the winter when daylight hours become shorter.psychologist hypothesised it’s due to melatonin. During the night the pineal gland secretes melatonin until dawn when there is increased light so during winter lack of light= longer secretion. Though to have a knock in effect on the production of serotonin in the brain leading to depressive symptoms
- EVAL=treatment. lightbox

-Kleitman (1957) monitored sleep patterns of 9 adults in a sleep lab. Brain activity recorded on a EEG and researched controlled the effects of caffeine and alcohol. REM activity was highly correlated with experience of dreaming. Participants woken up during dreaming repeated very accurate recall of their dreams.
- replications noted similar findings

Question 40

Treatment of SAD

Answer 40

• a Lightbox which resets melatonin levels. Strong light in the morning and evening

Question 41

Endogenous pacemakers

Answer 41

-internal mechanism that governs our biological rhytms
-the Suprachiasmatic nucleus= primary endogenous makes
- DeCoursey et al (2000)= destroyed the SCN in 30 chickmunks who were returned to their natural habitat and observed for 80 days. The sleep/wake cycle of the chickmunks disappeared and by the end a significant proportion died due to them presumably being awake and vulnerable when they should have been asleep.

• ralph et al (1990) bred ‘mutant’ hamsters with a 20 hour sleep/wake cycle. SCN cells from the mutant Hamsters were transplanted into the brains of normal hamsters, the cycles of the hamsters defaulted to 20 hours.
• Both show SCN role in establishing and maintaining the sleep/wake cycle
• SCN passes info on day length and light to the pineal gland which secretes melatonin.

Question 42

Exogenous zeitgebers

Answer 42

-external factors in the environment that reset our biological clocks
- light plays a role
Campbell and Murphy (1998) demonstrated light is detected by skin receptors and its not exclusive to receptors received by the eyes. 15 participants were woken up at various times and a light pad was shone at the back of their knees. This produced a deviation in their sleep/wake cycle of up to 3 hours in some cases.
- social cues
Infants are born with a random sleep l/wake cycle it begins around 6weeks and by 16 weeks infants are usually entrained. Schedules imposed by parents e.g. bedtimes and meal times are likely the key influence. Research suggest adapting to local eating and sleeping times is effective way to entrain circadian rhythms and beat jeg lag

Question 43

Evaluation of endogenous and exogenous zeitgebers

Answer 43

• Ralph et al study= ethical issues with animal studies + not been repeated
• influence of exogenous zeitgebers may be overstated
  Miles et al (1977) recounts a story of a young man, blind from birth, with a circadian rhythm of 24.9 hours. Despite exposure to social cues his sleep/wake cycle could not be adjusted, and consequently he had to take sedatives at night and stimulates in the morning to keep pace with the 24 hour sleep world.
  + also individuals who live in artic regions show normal sleep patterns despite prolonged exposure to light.

-only exceptional circumstances are endogenous pacemakers unaffected by influence of exogenous zeitgebers
- full isolation is rare like stiffer so could be judged as lacking validity
-they interact in real-life so makes little sense to separate them for the purpose of research