Experiments

• Split Brain Research - Roger Sperry (1968)
• Split-brain experiments


  Conducted by Roger Sperry, including the 'divided field experiment where words are projected on the right and left fields of vision to test patients' responses
• Split-brain experiment results


  • Patients could say words presented on the right visual field controlled by the left hemisphere, but not on the left visual field controlled by the right hemisphere. They could draw or pick up objects related to the left visual field due to the right hemisphere controlling motor movements of the left hand
• Major findings from Sperry's research

  • Hemispheres operate independently
  • Hemispheres are contralateral
  • Left hemisphere is linked to language skills/words/ability to speak
  • Right hemisphere is linked to spatial awareness/images
• Walter Freeman (1936-1945) pioneered lobotomies in the US and helped open the psychiatric world to the idea of psychosurgery
• At the time, lobotomies were seen as a possible treatment for severe mental illness like schizophrenia and depression
• Lobotomies involved severing the connection between the frontal lobe and other parts of the brain to eliminate excess emotion and stabilize personality
• Transorbital lobotomies


  A new procedure formulated by Walter Freeman involving severing connections to the prefrontal cortex and frontal lobe
• Many people who received transorbital lobotomies lost their ability to feel intense emotions, appearing childlike and less prone to worry
• Phineas Gage


  • Provided early evidence that specific areas of the brain are associated with distinct functions, particularly in terms of personality and behaviour, before the accident Gage was known for being a responsible and mild-mannered individual, after injury personality changed and became impulsive, irritable, and displayed poor decision-making, Gage's injury primarily affected his frontal lobe, personality changes were directly linked to the frontal lobe, served as an early piece of evidence supporting the idea that different areas of the brain are responsible for different cognitive and behavioural functions, Gage's case attracted the attention of scientists and researchers in the mid-19th century, Gage's case was instrumental in promoting the idea that the brain is not a homogeneous organ but a complex structure with specialised regions, discussions on how damage to specific brain areas can result in specific cognitive and behavioural changes
• Roger Sperry


  • Theorised about the chemicals and axons in the brain, wanted to understand how the nervous system could develop from a group of individual nerves within the body, conducted experiments with the assistance of a participant with epilepsy who had undergone brain surgery to treat his seizures, surgery involved cutting the participant's corpus callosum in half to cut the connection between the two sides of the brain, participant seemed to act normally afterwards, but they realised that it was difficult for him to name objects and had difficulty following particular to assemble blocks, after repeated attempts they realised that some tasks were more difficult depending on the instructions they gave the participant, also did the experiment on cats and monkeys, split-brain cats and monkeys had brain hemispheres that could not communicate with each other, each hemisphere acted as a separate brain
• Walter Freeman


  • Showed the role of the prefrontal cortex using frontal lobotomy, lobotomy is a surgical procedure that involves damaging or disconnecting the prefrontal cortex from the rest of the brain, was used as a treatment for various psychiatric and behavioural disorders, some believed it could alleviate symptoms and improve the lives of those suffering from mental illness or epilepsy, Freeman is most closely associated with the "transorbital" or "ice-pick" lobotomy which was a less invasive form of the procedure, a thin, sharp instrument was inserted through the eye socket and used to cut or damage brain tissue, goal was to disconnect or damage the prefrontal cortex as Freeman believed could alleviate psychiatric symptoms, range of ethical issues as patients were unable to withdraw and there were concerns about informed consent