Biopsychology - Brain

Question 1

What are the three main sections of the brain?

Answer 1

• forebrain
• midbrain
• hindbrain

Question 2

What are the four main regions of the brain?

Answer 2

• cerebrum (cerebral hemispheres) = forebrain
• diencephalon = forebrain
• cerebellum = hindbrain
• brainstem = mid/hindbrain

Question 3

What is the cerebrum?

Answer 3

• largest section of the brain
• split into two hemispheres (left/right)
  
  • they communicate via the corpus collusum
• four lobes:
  
  • frontal =
  • occipital
  • temporal
  • parietal

Question 4

What is the diencephalon?

Question 5

What is the cerebellum?

Question 6

What is the brain stem?

Question 7

What is localisation of function?

Answer 7

• the idea that specific functions (language, memory) have specific locations in the brain

Question 8

What are the motor and somatosensory areas of the brain?

Answer 8

• somatosensory cortex:
  
  • receives sensory input from receptors in the skin
  • located in parietal lobe
  • face and hands take up over half the somatosensory area
• motor cortex:
  
  • generates voluntary movements
  • located in the back of frontal lobe
  • both hemispheres control the muscles on the opposite side of the body

Question 9

What are the visual and auditory centres of the brain?

Answer 9

• visual centre:
  
  • located in occipital lobe
  • requires additional processing in neighbouring areas (perception)
  • where sensation is converted into perception
• auditory centre:
  
  • most of it is located in the temporal lobes of both the left and right hemispheres
  • begins in the inner ear where sound waves are converted to nerve impulses
  • this then travels via the auditory nerve to the auditory cortex

Question 10

What are the language centres of the brain?

Answer 10

• Broca’s area: (motor region)
  
  • patient named Tan was able to understand a spoken language but could not speak it or put his thoughts into words
  • found that the language centre is in the frontal lobe of the left hemisphere
• Wernicke’s area: (sensory region)
  
  • found in the left temporal lobe
  • involved in understanding language

Question 11

What are the strengths of localisation of function?

Answer 11

• brain scan evidence of localisation
• neurosurgical evidence
• case study evidence:
  
  • Phineas Gage forced temporal lobe out of his brain
• aphasia study support

Question 12

What are the weaknesses of localisation of function?

Answer 12

• challenges to localisation = reductionist:
• plasticity argues against this theory
• individual differences:
  • difference in patterns of activation across individuals

Question 13

What is brain lateralisation?

Answer 13

• idea that the two halves of the human brain are not exactly alike
• each hemisphere has functional specialisations
  
  • left = language
  • right = visual-motor tasks
• corpus callosum allows for the communication between the two hemispheres

Question 14

What is the right hemisphere dominant in?

Answer 14

• emotion
• spatial relationships

Question 15

What is the left hemisphere dominant in?

Answer 15

• language

Question 16

What are the strengths of lateralisation?

Answer 16

• helps to understand how specific functions are located on specific sides of the brain (multitasking)
  
  • enhances brain efficiency
• can study left handedness and why they may be prone to allergies/illness
  
  • link between immune system and lateralisation

Question 17

What are the weaknesses of lateralisation?

Answer 17

• changes with age, so this theory is not set in stone
  
  • language became more lateralised to the left hemisphere up to the age of 25
• does not explain brain plasticity
  
  • studies show that having one damaged hemisphere is not abnormal
  • other hemisphere can take over the functions of the damaged hemisphere

Question 18

What is split-brain research?

Answer 18

• used to study brain lateralisation
• cutting of the corpus callosum is called commissurotomized
  
  • communication between the hemispheres is stopped

Question 19

What is Sperry and Gazzaniga’s (1967) research?

Answer 19

• examined the extent to which two hemispheres are specialised for certain functions
• image/word projected in left or right visual field
  
  • describe what you see
  • tactile (touch)
  • drawing task

Question 20

What did Sperry and Gazzaniga find?

Answer 20

• describe what you see:
  
  • picture in right VF patient could verbally describe what they saw
  • in left VF they could not describe the picture
• tactile test:
  
  • right hand = could verbally describe object
  • left hand = could not describe it, but could select similar objects
• drawing task:
  
  • when pic presented to RVF, right hand could not draw as clear as the left hand
  • LVF = left hand would consistently draw clearer images
  • ** shows the superiority of the right hemisphere **
• ** left hemisphere is dominant in speech and language **

Question 21

What is Turk et al’s (2002) study?

Answer 21

• 48-year-old JW had commissurotomy for epilepsy
• stimuli
  
  • morphed faces
  • JW’s own and one of the researchers
  • 0% JW’s face to 100% JW
• divided the field procedure to present stimulus to one or other hemisphere
• JW asked to press button if image was of his face/familiar other person
• results = right hemisphere showed clear bias identifying morphed faces as familiar
• left hemisphere showed bias towards identifying morphed faces as himself
• ** right is better at face processing and left is better at self-recognition **

Question 22

What are the strengths of split brain research?

Answer 22

• proves that there is hemispheric lateralisation
  
  • both hemispheres have different functions
• research support for lateralisation through SBR
  
  • shows that the connectivity between the different areas is important
  • cutting of corpus callosum caused patients to struggle with verbally naming an object placed in the left hand

Question 23

What are the weaknesses of split brain research?

Answer 23

• has not shown that brain is organised into different areas with specific tasks
• SBR research had a small sample size
  
  • some of the sample did not fully cut communications between the hemispheres
  • they were an extremely varied group in terms of age, when epilepsy was developed and age of testing
• this makes the results less likely to be generalised to a wider population
• SBR is rarely carried out these days due to modern technology, so it lacks temporal validity

Question 24

What is brain plasticity?

Answer 24

• ability of the brain to change and adapt synapses, pathways, and structures in light of various experiences or after damage caused by trauma

Question 25

What is Villablanca and Hovda’s (2000) study?

Answer 25

• plasticity in newborn brain:
  
  • by the end of the first year, brain has more synapses and neurons than it will have when fully matured
  • developing brain is exposed to a vast range of experiences, environment and stimuli
• hemispherectomy research where baby has one severely damaged hemisphere
  
  • when it is removed soon after birth, the adult shows very few behavioural or cognitive impairments

Question 26

What is Boyke et al’s (2008) study?

Answer 26

• plasticity as a result of new life experience:
  
  • new experiences = nerve pathways developed
  • 60 year olds taught new skill (juggling)
  • found an increase in grey matter in the visual cortex
• ** when practise stopped, changes were reversed **

Question 27

What is Davidson’s (2004) study?

Answer 27

• plasticity and meditation:
  
  • meditation can change the inner workings of the brain
  • 8 Tibetan meditation monks and 10 volunteers were asked to meditate for short periods
  • electrodes picked up greater gamma waves (coordinate neuron activity) in monks

Question 28

What are the strengths of plasticity?

Answer 28

• research support from animal studies
  
  • Kempermann (1998) found increased no. of new neurons in rats in complex houses than in cages
  • associated with new memories and ability to navigate from different locations
  • Blakemore and Mitchell (1973) found that characteristics of visual neurons were changed by exposure to diff. environments
  • kittens in black vertical striped environment did not respond to horizontal black stripes
  • ** may be difficult to generalise to humans as this as conducted on cats (raised in only one env.) **
• research support from human studies:
  
  • Maguire (2000) studied London taxi drivers and found that the front part of their hippocampus was larger than the control ppts
  • positively correlates to how long they had been driving for
• age differences:
  
  • Bezzola (2012) found how 40 hours of golf training produced changes in neural rep. of movement in ppts aged 40-60
  • motor cortex activity increased compared to before training
  • shows how people of all ages are able to improve their brain capacity

Question 29

What are the weaknesses of plasticity?

Answer 29

• negative plasticity:
  
  • Medina (2007) found that brain’s adaptation to prolonged drug use leads to poor cognitive functioning
• generalisation issues:
  
  • studies carried out on animals are hard to generalise to the human population
  • e.g. kittens/rats are mobile at birth so their brain development is faster than humans
• ethical issues:
  
  • e.g. cats in Blakemore and Mitchell’s study were brought up in an ethically questionable environment

Question 30

What is functional recovery after brain trauma?

Answer 30

• transfer of functions from a damaged area of the brain to other undamaged areas in the brain

Question 31

What are common types of brain trauma?

Answer 31

• physical
• cerebral haemorrhage (stroke, blood vessel in brain bursts)
• cerebral ischaemia (stroke, blood vessel in brain blocked)
• viral/bacterial infections

Question 32

How does the brain naturally recover?

Answer 32

• brain is able to rewire and reorganise itself by forming new synaptic connections
• axonal sprouting:
  
  • growth of new nerve endings which connect with other undamaged nerve cells
• denervation supersensitivity:
  
  • axons that perform similar role become aroused to higher level to compensate for lost ones
• recruitment of homologous areas:
  
  • similar areas in opposite side of brain can take on the role of the damaged region
• neuronal unmasking (Wall 1977):
  
  • increasing rate of input to blocked (dormant) synapses can open them which allows for more connections to regions of the brain

Question 33

What is Danelli’s (2013) study?

Answer 33

• researchers used case study to support claims (Italian boy EB who lost linguistic abilities after brain tumour removal in left hem.)
  
  • right handed so language ability was in left hem.
• joined rehabilitation programme which helped to improve his linguistic abilities until he no longer struggled
• after testing at 17, they found that his right hem. had compensated for the loss of the left hem.
  
  • recruitment of homologous areas

Question 34

What are the strengths and weaknesses of functional recovery after trauma?

Answer 34

• practical application:
  
  • contributed to the field of neuro-rehabilitation
  • doctors provide therapy and electrical therapy to the brain
• age differences:
  
  • studies have shown that it is possible to improve abilities in adults with intensive retraining
  • ** however, capacity for neural reorganisation is greater in children than adults **
• educational attainment and functional recovery:
  
  • Schneider (2014) found that patients with college education are 7 times more likely to recover and be disability free after a year
  • suggests that young gen. should carry on with edu. to help recover
• gender differences:
  
  • women recover better as their function is not as lateralised as men
  • Ratcliffe (2007) found that women perform better on tests of attention/language while men performed better in visual analytical skills

Question 35

What are the ways of studying the brain?

Answer 35

• CT scans
• PET scans (glucose injected and accumulates in areas with greater activity)
• fMRI
• EEG
• ERP
• post-mortem examinations

Question 36

What is fMRI?

Answer 36

• indirectly measures blood flow through conc. of O2 in the bloodstream
  
  • signal used in fMRI is BOLD
• ppt may be asked to alternate between diff. periods of doing tasks to identify active parts of the brain

Question 37

What are the strengths/weaknesses of fMRIs?

Answer 37

• strengths:
  
  • non-invasive technique (allows more patients to undertake fMRI scans)
  • good spatial resolution - smallest feature a scanner can detect (allows psychologists to distinguish between diff. brain regions)
• weaknesses:
  
  • causation - fMRI scans do not provide a direct measure of neural activity (not clear whether brain region is associated with a particular function)
  • poor temporal resolution (1-4 seconds, low accuracy)
  • can only provide info on brain region and not individual neurons

Question 38

What is EEG?

Answer 38

• provides an overall view of brain electrical activity
• small electrodes (24/32) are used on the skull and pick up elec. activity of millions of neurons
  
  • amplitude = size/intensity
  • frequency = speed/rapidity
• two states of EEG:
  
  • synchronised pattern: recognisable waveform is identified
  • desynchronised = no recognisable waveform
• can be used to detect various types of brain disorder/disease

Question 39

What are the strengths/weaknesses of EEGs?

Answer 39

• strengths:
  
  • provides recordings of the brain’s activity in real time (temporal resolution)
  • provides invaluable diagnosis of conditions like epilepsy (contributed to our understanding of stages involved in sleep - ultradian rhythms)
• weaknesses:
  
  • can only detect activity in superficial regions of the brain and not deeper regions - e.g. hypothalamus
  • not useful for pinpointing exact source of neural activity (poor spatial resolution)

Question 40

What is ERP?

Answer 40

• very small voltage changes in the brain which are triggered by specific events/stimuli
• psychologist looks for specific electrical responses to the stimulus shown
  
  • this is done multiple times with the same stimuli to separate the electrical activity and overall activity
    - event-related potential then emerges

Question 41

What are the strengths/weaknesses of ERPs?

Answer 41

• strengths:
  
  • short latency - can reflect early stages of cog. processing (interval between stimulus presentation and beginning of ERP)
  • can measure processing of stimuli even in absence of behavioural response
• weaknesses:
  
  • poor spatial resolution (not possible to localise ERPs components to specific areas of the cortex)
  • lack of standardisation in methodology so findings from studies are hard to generalise (extraneous variables must be minimised)

Question 42

What are post-mortem examinations?

Answer 42

• when a person dies, researchers compare their brain to look for abnormalities
  
  • e.g. Broca examined brain of man with displayed speech problems
  • Wernicke discovered region where language is processed
• allows for a more detailed examination of anatomical and neurochemical aspects of the brain

Question 43

What are the strengths/weaknesses of post-mortem examinations?

Answer 43

• strengths:
  
  • enables researchers to examine deeper regions of the brain such as the hypothalamus and hippocampus
  • Harrison (2000) claimed that post-mortem studies have played huge role in understanding of mental illnesses
• weaknesses:
  
  • too many individual differences (length of time between death and post-mortem, drug treatment, age)
  • ethical issues in terms of consent (especially as this is carried out on patients with severe psychological deficits)
  • retrospective as person is already dead so follow ups cannot be made