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Cognitive Neuropsychology

Warwick in London Summer School. Cognitive Neuropsychology. Dr. Gemma Gray g.gray@warwick.ac.uk. Learning Objectives. After today’s lecture, you will be able to: Give a brief overview of major neuroanatomy Explain what cognitive neuropsychology is

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Cognitive Neuropsychology

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  1. Warwick in LondonSummer School Cognitive Neuropsychology Dr. Gemma Gray g.gray@warwick.ac.uk

  2. Learning Objectives • After today’s lecture, you will be able to: • Give a brief overview of major neuroanatomy • Explain what cognitive neuropsychology is • Describe some famous case studies and what they have told us about the brain • Describe what disorders of vision, action and speech tell us about normal brain function

  3. Introduction to the brain What is cognitive neuropsychology? Case studies and what they tell us

  4. The Brain • Squishy! • Cerebral Cortex: outer layer of the brain • Convoluted: Gyri – ridges, Sulci – grooves • Two hemisphere joined by the corpus callosum Corpus callosum Sulci Gyri

  5. The Brain • Each hemisphere has 4 lobes • Frontal Lobe: planning, decision making • Parietal Lobe: somatosensory functioning • Temporal Lobe: Hearing, memory • Occipital Lobe: vision • Cerebellum: Balance and coordination

  6. The Brain • Contralateral control: Each hemisphere controls the opposite side - vision, attention, action

  7. Brain imaging • Electroencepholo-graphy (EEG) • Positron Emission Topography (PET)

  8. Brain imaging • Magnetic Resonance Imaging (MRI) • Functional Magnetic Resonance Imaging (fMRI) • Transcranial Magnetic Stimulation (TMS) https://www.youtube.com/watch?v=iSOfP5w_AHY

  9. What is cognitive neuropsychology?

  10. What is cognitive neuropsychology? • Study of cognitive impairments following brain injury • Looks at individual cases to determine what processes have been disrupted • Develop understanding of normal cognitive processing

  11. What is Cognitive Neuropsychology • Looks at case studies of patients with brain lesions • Uses this information to understand normal cognitive ability • Uses a variety of neuropsychological tests to understand the patients impairment

  12. Associations and Dissociations • Associations: clusters of abilities or tasks that patients can’t do • Conclude that damaged area of the brain is involved in both tasks Control Test Performance Patient A Speech Task A Reading Task B

  13. Associations and Dissociations • Dissociation: a patient who is impaired at one task but normal at another • Double dissociation: 2+ patients with opposing deficits • Conclude that two functions involve separable processes Patient B Test Performance Patient A Speech Memory

  14. Modularity • By looking at what mental processes are disrupted by brain injury • We can make some conclusions about normal functioning

  15. Single Case Studies • Looking at the abilities of single patients with brain injury • Compared to abilities of age matched controls • BUT individual differences between patients

  16. Assessment • Cognitive assessment: a range of tests designed to assess normal etc. • More specific tests used to determine more specific cognitive problems, i.e. where in the processes problems lie.

  17. Single case studies and what they tell us about the brain

  18. Famous cases Phineas Gage • Railway worker who had an accident • Accident caused a metal rod to pierce his brain (orbito-frontal areas, Damasio et al., 1994) • Massive personality change following accident

  19. Conclusions • Frontal lobes are involved in… • Personality: “vulgar… intolerable to decent people” • Inhibition: “impatient of restraint or advice when it conflicts his desires” • Planning: Abandoning “future plans for others that appear more feasible”

  20. HM (Scoville and Milner, 1957) • Parts of temporal lobe and hippocampus removed to control seizures • Following surgery: • Retrograde amnesia: remembering past events • Antegrade amnesia: learning new information

  21. HM (Milner, 1962) • Mirror drawing task: assesses motor learning • Normal mirror drawing performance: Intact procedural memory

  22. Clive Wearing www.youtube.com/watch?v=Vwigmktix2Y

  23. Conclusions • Hippocampus and temporal lobe important for forming memories • Dissociation between different memory systems: STM, LTM and procedural knowledge • HM and Clive Wearing: Problem with memory consolidation – transferring information from STM to LTM

  24. HJA • Stroke resulting in occipital lobe damage • Resulted in visual problems • Unable to recognise objects – visual agnosia ‘I have not the glimmerings of an idea. The bottom point seems solid and the other bits are feathery. It does not seem logical unless it is some sort of brush’ Humphreys and Riddoch (1987)

  25. Conclusions • Impaired at recognising range of objects • Intact ability to copy pictures, to draw from memory and recognise objects from other modalities • HJAs problem is in perceiving the whole object

  26. Summary • Cognitive neuropsychology involves studying how the abilities of people with brain injury differ from people without brain injury • Case studies of patients with damage to different regions of the brain have informed much of our theories about normal behaviour

  27. Spatial Neglect

  28. Spatial Neglect • Spatial attention disorder: Fail to notice things in one side of space • Following injury to the parietal lobe and temporoparietal junction (usually RH) • Observable in different aspects of their daily life • https://www.youtube.com/watch?v=d4FhZs-m7hA

  29. Assessment of Spatial Neglect Drawing and copying tasks Bisection and cancelation tasks

  30. Is neglect person centred, object-centred, space centred…? • Varies according to the patient • Object centred or space-centred? Ogden scene copying task

  31. Is neglect person centred, object-centred, space centred…? • Varies according to the patient • Object centred vs. space-centred • Near Space vs. far space: Halligan and Marshall, 1991; Vuilleumier et al, 1998 • Personal vs peripersonal space

  32. Does neglect occur in imagination? • Varies according to the patient • Representational Neglect: Bisiach and Luzzatti (1978)

  33. Speech Disorders: Aphasia

  34. Aphasia • Inability to comprehend or produce speech • Broca (1861) Patient Tan: Broca’s aphasia (Expressive Aphasia) Can understand speech, but have trouble producing speech • Wernicke (1874) Wernickes’s aphasia (Receptive Aphasia) Can produce speech but have trouble understanding speech

  35. Goodglass (1983) Cookie theft task

  36. Videos of Brocas and Wernickes aphasia • Wernickes aphasia www.youtube.com/watch?v=3oef68YabD0 • Broca’s aphasia https://www.youtube.com/watch?v=JWC-cVQmEmY&t=84s

  37. What does aphasia tell us about speech and language? • Different parts of the brain are involved in speech production and speech comprehension • Distinction between Broca’s and Wernicke’s aphasia too simplistic • Other brain areas involved

  38. Summary • Cognitive neuropsychological assessment allows us to determine exactly where in a process a patient is impaired • By studying patients with brain injury we can determine how the brain normal processes information • Disorders such as neglect and aphasia have been investigated thoroughly to inform our understanding of language and attention

  39. Further Reading • Gazzaniga, M.S. (2018) Psychological Sciences • Chapter 3: Biology and Behaviour (Sections 3.2 and 3.4)

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