Year 2 Chapter 2 Biopsychology Flashcards
Name the 4 lobes of the cerebral cortex and one cortex that’s located in each
- Frontal lobe - Motor cortex
- Parietal lobe - Somatosensory cortex
- Occipital lobe - Visual cortex
- Temporal lobe - Auditory cortex
Name and describe the 4 areas of cortical specialisation in the brain
- 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
Outline the work of scientists, such as Broca and Wernicke, towards the understanding of the brain
- 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
Outline 2 study in which localisation of function in the brain has been investigated
- 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
- Tulving (1944)
Provide 2 pieces of supporting evidence for localisation of brain function
- 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
- Case study evidence
What is meant by plasticity and why does it challenge the idea of localisation?
- 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
- The brain physically adjusts the location of the function if damage occurs
Describe what’s meant by plasticity
- 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
Outline some research into plasticity
- Maquire et al (2000)
- Studied london taxi drivers
- More grey matter in their posterior hippocampus - spatial and navigational skills
- Their knowledge altered brain structure
How has research into brain plasticity help us in the real world? Use examples in your answers
- Neurorehabilitation
- Physiotherapy following illness or injury e.g. motor therapy and electric stimulus after a stroke
- Brain may be able to fix itself
What is meant by functional recovery?
- A form of plasticity
- After trauma, the brains ability to redistribute functions usually performed by the damaged area to an undamaged area
What happens to the brain during functional recovery?
- 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
- Axonal sprouting
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
- 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
Are there downsides to functional recovery?
- Negative plasticity
- Maladaptive - drug use leads to poor cognitive function
- Cognitive impairment and dementia (Medina et al, 2007)
- Phantom limb syndrome (Ramachandran, 1998)r
What other factors have been known to affect functional recovery?
- 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
Explain what’s meant by hemispheric lateralisation
- The two halves of the brain function differently
- Certain mental processes and behaviours are one hemisphere rather than the other
Outline the key study done by Sperry (1968). Included the aim, procedure and findings in your answer
- 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
Briefly evaluate the methodology in split-brain research
- 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
Why are there issues with generalizability in Sperry’s research?
- 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
The conclusions drawn from Sperry’s research are key contributors to our understanding of brain processes. Explain these conclusions
- 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
Explain why the difference in functions may be overstated
- 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
Name 4 ways of imaging the brain
- FMRI
- EEG
- ERPs
- Post mortem
Outline FMRIs as a way of investigating brain functions
- Monitors blood flow and oxygenation in the brain
- As areas become more active they require more oxygen
- Allows us to localize functions
Outline one strength and one weakness of FMRI scans as a way of identifying localisation of brain functions
- Good spatial resolution
- Low radiation - risk free and non-invasive
- Bad temporal resolution
- Cannot hone in on neural activity
- People have to lay still
Describe what an EEG is
- 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
Explain what’s meant by a biological rhythm
- Distinct patterns of changes in a body activity that conform to cyclical time periods
- Influenced by body clocks and external changes to the environment
Explain what is meant by a circadian rhythm and give one example
- Sleep/wake cycle
- A type of biological rhythm subject to a 24-hour cycle
Outline the aim, procedure and findings from Siffre’s cave study
- 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)
Out line 1 piece of research into circadian rhythms
- 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
Outline 2 practical applications of research into circadian rhythms
- 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
- Drug treatments
Outline two possible reasons why the result of research into circadian rhythms lacks generalisability
- 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
- Individual differences
What is an infradian rhythm?
-A type of biological rhythm that has a cycle of more than 24 hours
Give one example of a infradian rhythm?
-The menstrual cycle - governed by monthly hormone changes
Outline some research into infradian cycles?
- 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
What is seasonal affective disorder?
- 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.
What is an ultradian rhythm? Give an example
- A biological rhythm that occurs more than once in a 24 hour period
- The sleep cycle
Explain why the menstrual cycle is said to have an evolutionary bias
- 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
A lot of information on infradian and ultradian rhythms comes from animal studies. Evaluate this
- 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
Outline what’s meant by endogenous pacemakers and exogenous zeitgebers - refer to an example in your answer
- 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
Name and describe an endogenous pacemaker
- 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
- Tiny bundle of nerve cells located in the hypothalamus
Outline some research into the importance of endogenous on biological rhythms
- 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
What is an exogenous zeitgeber
-An external cue that may affect or entrain our biological rhythms
Name and describe 2 exogenous zeitgeber
- 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
Research suggests that the peripheral oscillators and other complex influences could act upon the sleep/wake cycle. Explain this research
- 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
Why is it suggested that the influence of exogenous zeitgeber has been exaggerated?
- 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
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
- 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
What are the ethical issues associated with the research into endogenous pacemakers and exogenous zeitgebers?
- 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
