Biopsychology

Question 1

What are the key features of the nervous system?

Answer 1

A specialised network of cells which transport electrical and chemical signals.

1) Collect, process and respond to information in the environment.

2) Co-ordinate working of different organs and cells.

Question 2

Describe the CNS

Answer 2

Central Nervous System (CNS)
- Made up of brain and spinal cord.

The brain is centre of conscious awareness, a highly developed cerebral cortex is what separates humans from other primates and has two hemispheres.

The spinal cord is an extension of the brain and responsible for reflex action. Passes messages to and from the brain and connects nerves to PNS.

Question 3

Describe the PNS

Answer 3

Peripheral Nervous System (PNS)
- Transmits messages via millions of neurons to and from the nervous system.

It divides into:

1) Autonomic Nervous System
- Governs vital (automatic) function of the body.
- Divides into Sympathetic and Parasympathetic.

2) Somatic Nervous System
- Receives information from sensory receptors to govern muscle movement.

Question 4

Describe the endocrine system.

Answer 4

Works alongside the nervous system to control vital functions using hormones. Works slower than electrical signals (seconds instead of milliseconds.

Glands:
- Organs which produce hormones. Pituitary gland is the “master gland” as it controls all other endocrine glands.

Hormones:
- Secreted in the bloodstream and affect any cell that has a receptor for it (lock and key model). E.g thyroxine affects cells in the heart.

Question 5

How do endocrine system and ANS work together?

Answer 5

Example: fight or flight response

• Stressor perceived by hypothalamus which activates pituitary.
• SNS (Sympathetic) is now aroused.
• Adrenaline released to deliver the arousal state which causes symptoms such as increased heart and breathing rate, plus dilated pupils.
• Immediate and automatic response when threat is perceived.
• PNS (Parasympathetic = the rest system) takes over once threat has passed.

Question 6

What are neurons and the 3 types of neuron?

Answer 6

Cells which transmit signals chemically and electrically to provide nervous system with communication. 100 billion neurons 80% located in the brain.

1) Sensory
- Carry messages from PNS to CNS. Long dendrites and short axons. Located in PNS.

2) Relay
- Connect between neurons (e.g sensory to motor). Have short dendrites and short axons. 97% located in brain and visual system.

3) Motor
- Connect CNS to muscles and glands. Short dendrites and long axons. Cell bodies in CNS but long axons in PNS.

Question 7

What is the structure of a neuron?

Answer 7

Cell body:
- Includes nucleus and genetic material.

Dendrites:
- Branch like structure which protrudes from the cell body. Carry nerve impulses from neighbouring cell to neuron.

Axon:
- Carries the electrical signal away from cell body. Covered in fatty myelin sheath for protection. Gaps called “nodes of Ranvier” speed up transmission impulse.

Terminal buttons:
- End of axon communicates with the next neuron across the synapse.

Question 8

What happens when a neuron is activated by a stimulus?

Answer 8

The inside of the cell becomes positively charged for a split second, causing an action potential to occur which creates an electrical impulse that moves down the axon.

Question 9

Describe the basic prosses of synaptic transmission.

Answer 9

Signals within the neuron are always electrical, between neurons they are always chemical.

When electrical impulse is at end of neuron (presynaptic terminal) it triggers the release of neurotransmitter from synaptic vesicles.

Neurotransmitter crosses gap and is taken up by postsynaptic receptor site meaning the signal only ever goes one way.

Question 10

What are neurotransmitters?

Answer 10

Chemicals that diffuse across the synapse and each has its own specific molecular structure it fits into on the receptor site, lock and key model.

Examples:
- Serotonin affects mood and social behaviour.
- Acetylcholine causes muscles to contract.

Question 11

What is inhibition and exhibition?

Answer 11

Neurotransmitters create either an inhibitory or exhibitory effect.

Inhibition:
- Increases the negative charge of the postsynaptic neuron, making it less likely the neuron will fire.
- e.g. Serotonin

Exhibition:
- Increases the positive charge of the postsynaptic neuron, making it more more likely the neuron will fire.
- e.g. Adrenaline.

Impulses are added up and must reach a certain threshold for an action potential to occur. Either the add up is exhibitory or inhibitory.

Question 12

Outline the localisation of function in the brain.

Answer 12

Holistic theory (all parts of brain involved in thought and action) replaced by localisation theory in the 19th century.

The brain is divided into two hemispheres and lateralised (certain functions mainly controlled by one side e.g left controls right side of body).

Outer layer of the brain is the cerebral cortex, its 3mm thick and humans is far more developed than all others. Its also called grey matter.

Cerebral cortex of both hemispheres is divided into four lobes:
1) Frontal lobe = motor area
2) Parietal lobe = Somatosensory area
3) Occipital lobe = visual area
4) Temporal lobe = Auditory area

Question 13

Describe the language centres of the brain.

Answer 13

Broca’s area:
- Speech production, in frontal lobe.
- Broca’s aphasia causes slow, laborious speech which lacks fluency.

Wernicke’s area:
- Language understanding, in temporal lobe.
- Wernicke’s aphasia produce language with ease but is mostly nonsense words with no meaning.

Question 14

Give two positive evaluations of localisation of function in the brain.

Answer 14

1) Brain scan evidence:
Peterson et al.
- Showed Wernicke’s area was active during a listening task, and Broca’s area active during a reading task.
Tulving et al.
- Showed semantic and episodic memories are located in different parts of the frontal cortex.

2) Supported by neurosurgery:
Dougherty et al.
- Neurosurgery is used to treat mental disorders.
- Studied 44 people with OCD who had a cingulotomy. At follow-up, 30% met he criteria for successful response and 14% for partial response. Success of such procedures suggest behaviours associated with serious mental disorders may be localised.

Question 15

Give two negative evaluation of localisation of function in the brain.

Answer 15

1) Language localisation model questioned:
Dick and Tremblay
- Very few researchers still believed language is restricted to B and W areas. Advanced techniques also reveal areas in right hemisphere and the thalamus. Suggests language may be organised more holistically.

2) Case study evidence:
- Yes there is Phineas Cage and patient KM, but it is hard to make generalisations based on single individuals.

Question 16

Outline hemispheric lateralisation

Answer 16

The brain is lateralised (two hemispheres) with some functions being localised.

Localised and lateralised:
- Some functions are both localised and lateralised.

Contralateral:
- One side of brain controls function on opposite side of body.

Contralateral and ipsilateral:
- Left visual field (LVF) of both eyes is connected to RH and LH, same with the RVF.
- Same arrangement for auditory functions.

Question 17

Describe a procedure and findings into split-brain research.

Answer 17

Sperry

Procedure:
- Corpus callosum can be severe (separates the Hs) for those with sever epilepsy.
- 11 split-brain participants were studied. Shown image or word projected to RVF (LH) or LFV (RH). Presenting image to one hemisphere only meant information could not be shared across the two.

Findings:
- Object shown to RVF could be described (language is LH).
- Object shown to LVF could not be described or named, but participants could select a matching or closely associated object.
- Demonstrates how certain functions are lateralised.

Question 18

Give one positive and negative evaluation of hemispheric lateralisation.

Answer 18

1) Evidence of lateralised brain function in “normal” brains.
- PET scans show when “normal” participants attend to general image elements, RH is more active. With focus of finer detail, LH is more active. Suggests lateralisation is a feature of “normal” brain.

2) Idea of analyser versus synthesiser brain may be wrong.
Nielsen et al.
- Research suggests people do not have a dominant side. Analysis of 1000 brain scans, showed lateralisation but not dominance.
- Idea of left or right brain people is wrong.

Question 19

Give one positive and negative evaluation of split brain research.

Answer 19

1) Support from more recent split-brain studies:
Luck et al.
- Demonstrated split-brain participants twice as fast at identifying the odd one out of similar objects. In neurotypical brain, LH’s superior processing abilities watered down by RH. Supports Sperry’s findings of left and right brain having distinct functions and abilities.

2) Causal relationships hard to establish:
- Sperry’s research compared split brains against neurotypicals. But none of the controls had epilepsy. Was the difference due to split-brain or epilepsy?

Question 20

Outline plasticity

Answer 20

The brain is “plastic” with synaptic connection form and are pruned.
- Growth of synaptic connections peak at 2-3 years of age, at around 15,000.
- Rarely used connections are deleted, frequently used ones are strengthened.
- Neural connections can be formed at any time during your life (learning).

Question 21

Which two studies support plasticity?

Answer 21

1) Taxi driver study:
Maguire et al.
- London cabbies had more matter in the posterior hippocampus than control group. This part of the brain is linked to development of spatial and navigational skills, those who had been in the job longest had a more developed PH.

2) Images of medical students:
Draganski et al.
- Images three months before and after finals. Physical development was visible in areas linked with learning.

Question 22

Give one strength and one limitation of plasticity.

Answer 22

1) Plasticity may not decline sharply with age:
Ladina Bezzola et al.
- 40 hours of golf training produced changes in the neural representations in participants aged 40-60. Using fMRI, motor cortex activity in the novice golfers was reduced compared to a control group. Suggests greater efficiency after training. Neural plasticity can continue throughout life.

2) Plasticity has possible negative behavioural consequences.
Medina et al.
- Brain’s adaption to prolonged drug abuse led to poorer cognitive function later on in life.
- 60-80% of amputees have phantom limb syndrome.
- Brains ability to adapt is not always beneficial and my lead to physiological and psychological problems.

NOTE
2) Is not really a negative evaluation of research, just a downside of plasticity. The evaluation DOES NOT reduce validity.

Question 23

Outline functional recovery of the brain after trauma.

Answer 23

Following trauma, unaffected areas of the brain take over “lost functions”.

The brain “rewires” itself by forming new synaptic connections. Secondary neural pathways (like a backup power generator) carry out “lost” functions.

Structural changes in the brain occur:

1) Axonal sprouting:
Nerve ending growth connects with undamaged areas to form new “pathways”.

2) Denervation super-sensitivity:
- Axons that do a similar job are put on higher levels of arousal to compensate for ones that are lost.

3) Recruitment of homologous area:
- Opposite side of brain takes over different tasks.

Question 24

Give one positive and one negative evaluation of functional recovery of the brain after trauma.

Answer 24

1) Real-world application:
- Understanding plasticity has led to neuro-habilitation. Understanding axonal growth encourages new therapies.

2) Neural plasticity may be related to cognitive reserve:
Schneider et al.
- Compared how long patients spent in education (indicated cognitive reserve) and chances of disability free recovery. 40% of patients with 16 plus years in education had DFR, compared to 10% who had less than 12 years. Suggests that cognitive reserve is a crucial factor in determining how well brain recovers.

Question 25

Outline ways of studying the brain and four techniques.

Answer 25

Psychologists use medical techniques to investigate brain localisation.

1) fMRI
- Highlights active areas of the brain by detecting changes in blood and oxygen flow.

2) EEG
- Shows overall electrical activity via electrodes on a skull cap.

3) ERP
- Brainwaves related to particular events.

4) Post-mortems
- Examinations of dead brains.

Question 26

Give one positive and one negative of fMRIs

Answer 26

Positive:
- Its safe because it does not rely on the use of radiation. It also produces images with high spatial resolution which are accurate to the mm.

Negative:
- It is very expensive. It has poor temporal resolution because there is a 5-second lag between initial neural activity and image.

Question 27

Give one positive and one negative of EEGs

Answer 27

Positive:
- It has high temporal resolution, brain activity in one millisecond.

Negative:
- EEG produces a generalised signal from thousands of neurons. It is difficult to know the exact source of neural activity.

Question 28

Give one positive and one negative of ERPs

Answer 28

Positive:
- Measures of neural processes more specific with ERPs than EEGs. Excellent temporal resolution.

Negative:
- Lack of standardisation makes it difficult to confirm findings in studies involving ERPS. Any background stimulus must be removed.

Question 29

Give one positive and one negative of post-mortem examinations.

Answer 29

Positive:
- Can be used in localised and medical research (can be repeatedly studied once collected).

Negative:
- Knowing causation of damage is tricky and there are ethical issues (consent after death).

Question 30

Outline circadian rhythms.

Answer 30

Biological rhythms are patterns of changes in body activity that conform to a cyclical time period and are governed by:
- Endogenous Pacemakers (Internal clock/ EP)
- Exogenous Zeitgebers (External cues/ EZ)

The circadian rhythm lasts about 24 hours and there are several important circadian rhythms/ cycles.

Sleep/wake cycle is governed by internal and external mechanisms.
- Endogenous Pacemakers = A free running biological clock when there’s no sunlight.
- Exogenous Zeitgebers = Tired when dark, alert when sunny. Effect of daylight. EZs reset the SCN.

Superchiasmatic nucleus (SCN) governs basic rhythm by providing information from the eyes about light.

Question 31

Outline three studies into circadian rhythms.

Answer 31

1) Siffre cave studies
- Conducted studies where he lived in caves without light to examine the effect of free-running biological rhythms. Both times, his free-running rhythm settled at 25 hours.

2) Aschoff and Wever
- Had a group of participants do the same study as Siffre, but in a WW2 bunker. All but one participant had rhythms settle between 24 and 25 hours.

3) Folkard et al.
- 12 people in the cave when researchers slowly shortened their days to 22 hours by telling them when to sleep and wake. Only one participant comfortably adjusted. EPs are stronger than EZs.

Question 32

Give two positive evaluations of circadian rhythms.

Answer 32

1) Real-world application:
- Shift work creates desynchronization of rhythms which leads to issues so research has economic implications for how to best manage shift work.
Boivon et al.
- Reduced concentration at 6 am causes more accidents.
Knutsson
- Link to poor health, three times more likely to develop heart disease.

=> Counterpoint:
Soloman
- Studies are correlational, effects (such as divorce) may be due to disrupted social routines, not psychological impact.

2) Real-world application:
Bonten et al.
- Circadian rhythms guide bodies processes and this knowledge can be used to determine when is most effective to administer drugs.

Question 33

Give one negative evaluation of circadian rhythms.

Answer 33

Generalisations are difficult to make:
- Studies often use very small groups and participants may not be representative of whole population.
- Individual differences occur e.g Siffre noticed how his internal clock was much slower at 60 than when younger.

Question 34

Outline Infradian rhythms.

Answer 34

Biological rhythms with a duration of over 24 hours.

Exogenous Zeitgebers synchronise cycles:
Stern and McClintock
- Menstrual cycles synchronised using pheromones from armpits on cotton swabs. 68% of women had cycles closer to pheromone donor.

Seasonal Affective Disorder (SAD) is an infradian rhythm. Depression in winter due to low sunlight.
- SAD caused by over-secretion of melatonin due to lack of light which reduces serotonin levels.

Question 35

Outline Ultradian rhythms.

Answer 35

Biological rhythms with a duration of under 24 hours.

Sleep is an example of an Ultradian rhythm with multiple 90 minute cycles during sleep, each cycle has five stages:

• 1&2: Light sleep, brain produces alpha waves. In stage two, sleep spindles (random changes in pattern) occur. Easy to wake from.
• 3&4: Deep sleep, brain produces deep waves with lower frequency and higher amplitude (opposite to alpha waves). Hard to wake from.
• 5: REM (Rapid Eye Movement/ dream stage), the body is paralysed and the brain produces theta waves.

Question 36

Give one positive and one negative evaluation for Infradian rhythms.

Answer 36

1) An evolutionary basis:
- Advantageous for distant ancestors to menstruate at the same time. Pregnancy at same time means that if one mother dies, others are there to care for the child. Evolutionary explanations are strong.

2) Methodological limitations in synchrony studies:
Trevathan et al.
- Replicated Stern and McClintock’s original study and did not find the same results. There are others confounding variables that act on menstrual cycles. Synchronisation may occur by chance.

Question 37

Give one positive and one negative evaluation for Ultradian rhythms.

Answer 37

1) Understanding age-related changes in sleep:
Van Cauter et al.
- Slow wave sleep (SWS) reduces with age, but this is when growth hormone is produced. Explains ageing and impairments in old age.

2) Individual differences:
Tucker et al.
- Found large differences in duration of sleep stages especially 3&4. They suggest differences are biological in origin and so “normal” sleep is difficult to describe.

Question 38

Outline endogenous pacemakers and the sleep/ wake cycle.

Answer 38

Internal body clocks.

The suprachiasmatic nucleus (SCN) is a tiny bundle of nerves in the hypothalamus. It receives information about light from the optic chiasm where nerve fibres from the eyes cross.

Research into influence of SCN:

1) DeCoursey et al.
- SCN connections in chipmunks brains destroyed and they lost their sleep/wake cycle completely. Many were killed by predators when released.

2) Raph et al.
- SCN from bred “mutant” hamsters to have 20 hour sleep cycle transplanted into normal hamsters. 20 hour sleep cycle was developed.

SCN indicates day length to pineal gland which secretes melatonin when dark. They are both endogenous mechanisms.

Question 39

Outline exogenous zeitgebers and the sleep/wake cycle.

Answer 39

External environmental factors that reset biological clocks. Without external cues, free-running biological clock continues to click in a cyclical pattern.

Light is the main key EZ and can reset the EP.

Campbell and Murphy
- Woke up participants at various time, shone light at back of knees. Sleep/ wake cycle deviated by three hours. Light does not rely on eyes to influence the SCN.

Social cues have effect on sleep/ wake cycle. Sleep-wake cycle is random in human new-borns until about 16 weeks. Schedules imposed by parents e.g regular meal times and bedtimes have great effect.

Research shows adapting to local times for eating and sleeping reduces jet lag quicker by entraining circadian rhythms.

Question 40

Give two negative evaluation for Endogenous Pacemakers.

Answer 40

1) Beyond the master clock there are others:
Damiola et al.
- Changing feeding patterns of mice affected circadian rhythms in liver for up to 12 hours, leaving SCN unaffected.
- May be other complex influences on the sleep/ wake cycle aside from SCN.

2) Interactionist system:
- Research often looks at endogenous pacemakers and exogenous zeitgebers individually, when in reality they work in tandem. By isolating areas for study, researchers fail to represent real life and lower the validity (legitimacy) of the research.

Question 41

Give two negative evaluations of Exogenous Zeitgebers.

Answer 41

1) Effects of EZs differ in different environments:
- EZs do not have the same effect on people who live in areas of very little darkness or very little light. Artic has a six month straight darkness period, yet Innuits have a regular sleep schedule.

2) Case study evidence:
Miles et al.
- Blind from birth man with circadian rhythm of 24.9 hours. Despite exposure to social cues (EZs) his cycle could not be adjusted. Social cues are not enough to reset biological rhythms.