AO3

• Broca's area


  Brain region involved in language production
• Wernicke's area


  Brain region involved in language understanding
• Broca's aphasia


  • Speech that is slow, laborious and lacking in fluency
• Wernicke's aphasia


  • Inability to extract meaning from spoken or written words
• Damage to Broca's area


  Individuals develop expressive Broca's aphasia
• This demonstrates the important role that Broca's area plays in the production of language and the important role that Wernicke's area plays in the understanding of language
• Evidence from case studies of brain-damaged individuals

  • Supports the different functions of Broca's and Wernicke's areas in language production and understanding
• One strength is that there is evidence to support the different functions of Broca’s and Wernicke’s areas from brain scan studies. For example, Petersen et al. (1988) used brain scans to demonstrate that Broca’s area was active during a reading aloud task and Wernicke’s area was active during a listening task. This supports the suggestion that these areas of the brain have different functions. 

   
• Language production

  • Not confined to Broca's area alone
• Dronkers et al. (2007) re-examined the preserved brains of two of Broca's patients
• Purpose of the study

  Identify the extent of any lesions in more detail by using modern high-resolution MRI imaging
• The findings revealed that other areas besides Broca's area were damaged and therefore could have contributed to the patients reduced speech abilities
• This study suggests that language is far more complicated than once thought, and involves networks of brain regions rather than being localised to specific areas
• One weakness is that there is evidence that certain functions cannot be localised to specific areas of the brain. For example, Lashley (1950) removed areas of the cortex in rats that were learning their way around a maze. He found that no area was more important than any other in terms of the rats ability to learn their way through the maze. The process of learning appeared to require every part of the cortex rather than being confined to a particular area. This suggests that learning is too complex to be localised and requires the involvement of the whole brain.   
• What are the strength and weakness of Localisation fo function?


  + case studies for Broca's and Wernicke's

  + Petersen brain Broca active in reading alound Wernicke active in listening

  -Dronker rexamined Broca's patients other area damaged

  -Lashley rats removed cortex leanr maze requied all of cortex not particilar part.
• Sperry's research

  Has led to a growing body of pop-psychological literature that overemphasises and oversimplifies the functional distinction between the left and right hemispheres
• The 'verbal' and 'non-verbal' labels can be applied to summarise the differences between the two hemispheres, oversimiplified by pop-psychology
• In a normal brain, the two hemispheres are in constant communication
• Many of the behaviours typically associated with one hemisphere can be effectively performed by the other hemisphere when the situation requires it
• This suggests that differences in hemispheric function may have been overstated
• There is evidence that lateralisation of function does not stay the same throughout an individual's lifetime
• Lateralised patterns found in younger individuals tend to switch to bilateral patterns in older adults
• Lateralisation of function


  • Language becoming more lateralised to the left hemisphere with increasing age in children and adolescents
  • Lateralisation decreasing with each decade of life after the age of 25
• It is difficult to know why lateralisation of function changes over an individual's lifetime
• Weakness

  Research into split-brain patients can be criticised for lacking control
• Split-brain patients in Sperry's original study

  • All 11 had a history of epileptic seizures
• weakness of sperry research = Epileptic seizures may have caused unique changes in the brain that influenced the findings
• Some split-brain patients had experienced more disconnection between the two hemispheres than others
• Pathways connecting the two hemispheres

  • Corpus callosum
  • Anterior commissure
• In some cases, the anterior commissure was cut along with the corpus callosum, but in other cases it was left intact, possibly allowing for some communication between the two hemispheres
• Sperry's research was affected by extraneous variables, and therefore lacked internal validity
• One weakness is that research into split-brain patients uses very small sample sizes. For example, Andrews (2001) reported that many studies used as few as 3 participants, and some used just 1. This is because split-brain patients are very unusual, and commissurotomies are rarely carried out nowadays. This suggests that the findings of split-brain research lack external validity.  
• What are the weaaknes of sperry's research into hemipsheric laterilsation?

  • small smaple size low external validity
  • lack control previous brain damage, other small pathway, not all cute
  • SzarFlarski 25 laterisation decreases
  • pop-psychology, differences in hemispheric fucntion overstated
• One strength of understanding the processes involved in the functional recovery of the brain is that it has contributed to developments in the field of neurorehabilitation. Techniques include movement therapy and electrical stimulation of the brain to counter the deficits in motor or cognitive functioning that may be experienced following brain trauma. This suggests that research in this area has important applications to the real world.  
• There is evidence that a person’s educational attainment will influence how well the brain recovers after trauma. For example, Schneider et al. (2014) discovered that the more time brain injury patients had spent in education, the greater their chances of a disability-free recovery (DFR). There is also evidence that age can influence how well the brain recovers after trauma. This suggests that the ability of the brain to recover function after trauma is hugely complex and varies from person to person.  
• Evidence of brain plasticity also comes from animal studies. For example, Blakemore & Mitchell (1973) investigated the development of the visual cortex in cats. They found that kittens raised in an environment with vertical stripes did not respond to horizontal stripes as adults, and kittens raised in an environment with horizontal stripes did not respond to vertical stripes as adults. This suggests that the characteristics of the neurons in the visual cortex had been changed as a result of exposure to a specific environment soon after birth. 

   
• However, the research of Blakemore & Mitchell (1973) can be criticised.

  • inappropriate to generalise their findings to humans.
  • significant ethical issues with their research. kept in darkness, visual deficits. no startle response when an object was thrust towards them. This suggests that the kittens were not protected from psychological harm. 
• what are the strength and weakness of brain plasticity and fucntional recovery?

  + Blackemore and Mitchell kittern visusla cortx changed

  • Ethicial issues, can't generalise

  + devolpment of neurorehabitiltiation

  • Scheinder education =DFR recovery, highly complex
• Strengths of post-mortem examinations

  • No discomfort experienced by the individual because they are not alive
  • Post-mortem evidence was vital in providing a foundation for early understanding of key processes within the brain
• Post-mortem evidence used by researchers

  • Broca Wernicke