Year 2 Chapter 2 Biopsychology

Question 1

Name the 4 lobes of the cerebral cortex and one cortex that’s located in each

Answer 1

• Frontal lobe - Motor cortex
  
  • Parietal lobe - Somatosensory cortex
  • Occipital lobe - Visual cortex
  • Temporal lobe - Auditory cortex

Question 2

Name and describe the 4 areas of cortical specialisation in the brain

Answer 2

• Motor cortex - Voluntary movement
  
  • Somatosensory cortex - information from the skin (touch, pressure, heat, etc)
  • Visual cortex - Information from the eye, left visual field to right visual cortex and vice versa
  • Auditory cortex - speech based information

Question 3

Outline the work of scientists, such as Broca and Wernicke, towards the understanding of the brain

Answer 3

• They discovered the language areas of the brain
  
  • Broca’s area is in the frontal lobe and is responsible for speech production
  • Wernicke’s area is in the left temporal lobe and is responsible for speech understanding/comprehension

Question 4

Outline 2 study in which localisation of function in the brain has been investigated

Answer 4

• Peterson et al (1988)
  - Used brain scans to show how Wernicke’s area was active during a listening task and Broca’s area during a reading task
  - Shows they have different functions
  
  • Tulving (1944)
    
    • Showed that episodic memory and semantic memory are located in different parts of the prefrontal cortex

Question 5

Provide 2 pieces of supporting evidence for localisation of brain function

Answer 5

• Neurosurgical evidence
  - Dougherty (2002)
  - 44 OCD patients underwent a cingulotomy (removal of part of the brain)
  - After 32 weeks almost half of the patients had made either a partial or successful recovery from OCD
  - Suggest behaviour and mental illnesses are localised
  
  • Case study evidence
    
    • Phineas Gage
    • A steel rod went through part of his brain removing a lot of the left frontal lobe
    • Changed his personality from a relative nice person to rude, quick tempered and aggressive
    • Suggests localisation of brain functions

Question 6

What is meant by plasticity and why does it challenge the idea of localisation?

Answer 6

• When the part of the brain is damaged and a particular function of the brain has been lost another part of the brain appears to be able to take over this function.
  
  • The brain physically adjusts the location of the function if damage occurs
    
    • This suggests that functions are not fixed to a specific position
  • The brain is working as a whole unit rather than specific areas for specific purposes

Question 7

Describe what’s meant by plasticity

Answer 7

• The tendency of the brain to change and adapt as a result of experience
  
  • The experience results in some connection being lost and some being streangthened

Question 8

Outline some research into plasticity

Answer 8

• Maquire et al (2000)
  - Studied london taxi drivers
  - More grey matter in their posterior hippocampus - spatial and navigational skills
  - Their knowledge altered brain structure

Question 9

How has research into brain plasticity help us in the real world? Use examples in your answers

Answer 9

• Neurorehabilitation
  
  • Physiotherapy following illness or injury e.g. motor therapy and electric stimulus after a stroke
  • Brain may be able to fix itself

Question 10

What is meant by functional recovery?

Answer 10

• A form of plasticity
  
  • After trauma, the brains ability to redistribute functions usually performed by the damaged area to an undamaged area

Question 11

What happens to the brain during functional recovery?

Answer 11

• Secondary neural pathways are activated to carry out certain functions
  
  • Axonal sprouting
    
    • Growth of new nerve endings to connect to undamaged cells to create new pathways
  • New blood vessels are formed
  • Recruitment of similar areas
    
    • E.g. Broca’s area damaged on the left side, the area recruited would be on the right side

Question 12

Outline one example of animal research into plasticity and discuss if what we learn from such studies is worth the permanent damage done to the animals

Answer 12

• Hubel and Wiesel (1963)
  
  • Cats eye sewn shut
  • Both visual cortices took over functions for the other eye
  • Generalizability from cats to humans is an issue
  • We have no insight into thought or emotions of the animal
  • Plasticity may be different in animals

Question 13

Are there downsides to functional recovery?

Answer 13

• Negative plasticity
  
  • Maladaptive - drug use leads to poor cognitive function
  • Cognitive impairment and dementia (Medina et al, 2007)
  • Phantom limb syndrome (Ramachandran, 1998)r

Question 14

What other factors have been known to affect functional recovery?

Answer 14

• Level of education (Schneider et al, 2014)
  
  • The amount of time spent in education (greater cognitive reserve), the greater chance the person has of full functional recovery (DFR)
  • 40% of patients who achieved DFR had been in education 16+ years
  • 10% of patients who had 12 or less years of education achieved DFR

Question 15

Explain what’s meant by hemispheric lateralisation

Answer 15

• The two halves of the brain function differently

- Certain mental processes and behaviours are one hemisphere rather than the other

Question 16

Outline the key study done by Sperry (1968). Included the aim, procedure and findings in your answer

Answer 16

• Studied a group of patients who’d had their corpus callosum (bit that connects the two halves of the brain) severed
  
  • This allowed Sperry to investigate if each side of the brain was specialized for certain functions
  • Images or words projected into either the left or right visual field
  • Images presented in the left field could not be described
  • Although the images could not be identified with touch
  • Composite words - PPTs would use their left hand to write the word, but would say the word presented to the right visual field
  • Matching ace - the right hemisphere seems to be dominate in facial recognition

Question 17

Briefly evaluate the methodology in split-brain research

Answer 17

• Standard procedure
  
  • Only showed the images for one tenth of a second
  • Patients didn’t have time to use both eyes to view the image
  • Well controlled procedure

Question 18

Why are there issues with generalizability in Sperry’s research?

Answer 18

• Only 11 PPTs took part in the study
  
  • All had epilepsy - may have impacted the brains and the findings
  • The level of disconnections between the two hemispheres of the brain was different for all PPTs
  • The control group didn’t have epilepsy, this was inappropriate as they’re different from the experimental group in two ways
  • A control group who had epilepsy would’ve been better

Question 19

The conclusions drawn from Sperry’s research are key contributors to our understanding of brain processes. Explain these conclusions

Answer 19

• Left hemisphere = analytical and verbal tasks
  
  • Right hemisphere = spatial and music
  • The right hemisphere can only produce simple words but contribute emotional and holistic content
  • Left hemisphere is the analyzer and the right hemisphere is the synthesizer - A key contribution to our understanding of the brain

Question 20

Explain why the difference in functions may be overstated

Answer 20

• While the verbal and non-verbal descriptions of the left and right hemispheres may be useful in reality the distinction is less clear cut
  
  • In a normal brian the two hemispheres are in constant comunication
  • Many behaviours associated with one hemisphere can be carried out by the other is it’s needed

Question 21

Name 4 ways of imaging the brain

Answer 21

• FMRI
  
  • EEG
  • ERPs
  • Post mortem

Question 22

Outline FMRIs as a way of investigating brain functions

Answer 22

• Monitors blood flow and oxygenation in the brain
  
  • As areas become more active they require more oxygen
  • Allows us to localize functions

Question 23

Outline one strength and one weakness of FMRI scans as a way of identifying localisation of brain functions

Answer 23

• Good spatial resolution
  
  • Low radiation - risk free and non-invasive
  • Bad temporal resolution
  • Cannot hone in on neural activity
  • People have to lay still

Question 24

Describe what an EEG is

Answer 24

• A record of tiny electrical impulses produced by brain activity
  
  • By measuring characteristic brain patterns certain conditions of the brain can be measured e.g. epilepsy

Question 25

Explain what’s meant by a biological rhythm

Answer 25

• Distinct patterns of changes in a body activity that conform to cyclical time periods
  
  • Influenced by body clocks and external changes to the environment

Question 26

Explain what is meant by a circadian rhythm and give one example

Answer 26

• Sleep/wake cycle

- A type of biological rhythm subject to a 24-hour cycle

Question 27

Outline the aim, procedure and findings from Siffre’s cave study

Answer 27

• What would happen if our biological clocks were left to their own devices (No clocks or light) - would we still wake up and sleep at regular times
  
  • Siffre spent extended periods of time underground deprived of natural light
  • In each case his biological rhythm settled down to one that was just beyond 24 hours (around 25 hours)

Question 28

Out line 1 piece of research into circadian rhythms

Answer 28

• Ashoff and Wever (1976)
  
  • Participant in a world war ll bunker without natural light
  • All but one participant displayed a circadian rhythm of 24-25 hour
  • Natural sleep/wake cycle is slightly longer than 24 hours but is entrained by external factors

Question 29

Outline 2 practical applications of research into circadian rhythms

Answer 29

• Shift work
  - Research has shown that night workers are likely to experience a loss of concentration around 6 am (Boivin at al)
  - Late shift workers are more likely to experience heart disease, possibly due to the stress of having to adjust to poor sleep quality and an unusual sleep pattern
  
  • Drug treatments
    
    • Circadian rhythm coordinate basic processes in the body - pharmacokinetics (the actions of drugs on the body)
    • Research into circadian rhythms has revealed when drugs are likely to be most effective

Question 30

Outline two possible reasons why the result of research into circadian rhythms lacks generalisability

Answer 30

• Uses of case studies and small samples
  - Siffre - he was over 60 - he noticed that as he got older his circadian rhythm slowed
  
  • Individual differences
    
    • Some cycles vary between 13 and 65 hours in some cases (Czeisler et al)
    • Some people like to go to bed early and rise early and some do the opposite

Question 31

What is an infradian rhythm?

Answer 31

-A type of biological rhythm that has a cycle of more than 24 hours

Question 32

Give one example of a infradian rhythm?

Answer 32

-The menstrual cycle - governed by monthly hormone changes

Question 33

Outline some research into infradian cycles?

Answer 33

• Stern and McClintock
  
  • Took pheromone samples from women on their menstrual cycles (at different stages) and passed them onto other women
  • 68% experienced changes to their cycle that brought them closer to the pheromone donor
  • The menstrual cycle is an endogenous system but evidence suggests that it may be influenced by external factors

Question 34

What is seasonal affective disorder?

Answer 34

• A form of depression triggered by winter seasons
  
  • A particular type of infradian rhythm called a circannual rhythm
  • Possible that melatonin is implicated - during winter the production of melatonin continues for longer due to lack of light in the mornings, making us sleepier.

Question 35

What is an ultradian rhythm? Give an example

Answer 35

• A biological rhythm that occurs more than once in a 24 hour period
  
  • The sleep cycle

Question 36

Explain why the menstrual cycle is said to have an evolutionary bias

Answer 36

• Many confounding variables weren’t controlled during the study
  
  • Stress, diet, exercise, etc
  • Typically these studies are carried out on small groups of women who self report the findings
  • Other studies have even failed to find any form of synchrony in all female samples

Question 37

A lot of information on infradian and ultradian rhythms comes from animal studies. Evaluate this

Answer 37

• The fact that we know animals release pheromones to contact other animals is well documented
  
  • Evidence for the effects of pheromones in humans is still inconclusive

Question 38

Outline what’s meant by endogenous pacemakers and exogenous zeitgebers - refer to an example in your answer

Answer 38

• Endogenous pacemakers - internal body clocks that regulate our biological rhythms e.g. SCN
  
  • Exogenous zeitgebers - external cues that may affect or entrain our biological rhythms e.g. light

Question 39

Name and describe an endogenous pacemaker

Answer 39

• The suprachiasmatic nucleus (SCN)
  
  • Tiny bundle of nerve cells located in the hypothalamus
    
    • one of the primary endogenous pacemakers
  • SCN lies above the optic chiasm - receives information about light
  • Passes this information onto the pineal gland which is involved in the production of melatonin

Question 40

Outline some research into the importance of endogenous on biological rhythms

Answer 40

• DeCoursey et al
  
  • Damaged the SCN of chipmunks and released them into the wild
  • The sleep/wake cycle was affected (they didn’t sleep when they were supposed to)
  • Most of them died because they slept at the wrong times

Question 41

What is an exogenous zeitgeber

Answer 41

-An external cue that may affect or entrain our biological rhythms

Question 42

Name and describe 2 exogenous zeitgeber

Answer 42

• Light - affects the body’s main endogenous pacemaker and also has an indirect affect on key processes that control such hormone secretion and blood circulation
  
  • Social cue - Babies are entrained to have a circadian rhythm - schedules imposed by parents are likely to be important here

Question 43

Research suggests that the peripheral oscillators and other complex influences could act upon the sleep/wake cycle. Explain this research

Answer 43

• POs are circadian rhythms within cells and organs
  
  • These are affected by the SCN but also act independently
  • Damilola et al
    
    • Altered the circadian rhythm of the liver but left the SCN unaffected, other influences on the sleep/wake cycle are possible aside from the master clock

Question 44

Why is it suggested that the influence of exogenous zeitgeber has been exaggerated?

Answer 44

• Miles et al
  - A blind man’s circadian rhythm wasn’t affected when exposed to social cues
  
  • People who live in the arctic regions have normal sleeping patterns despite the absence of light

Question 45

Why is research into internal and external influences often considered as lacking validity? Explain how endogenous pacemakers and exogenous zeitgebers influence the sleep/wake cycle

Answer 45

• Total isolation studies are very rare - lacking validity
  
  • Free-running is very rare
  • In real life the two interact
  • The SCN controls melatonin + light stimulates the production of melatonin

Question 46

What are the ethical issues associated with the research into endogenous pacemakers and exogenous zeitgebers?

Answer 46

• A lot of studies done on animals - generalisability
  
  • More importantly - harm and risk when returning to natural habitat
  • They died
  • Bring about debates of whether or not what we learn is worth it