WK6 (M): Visual Agnosia

• What is Cognitive Neuropsychology?

  It studies cognitive impairments by examining what has gone wrong.
• How does Cognitive Neuropsychology help us understand cognitive processes?

  By using patterns of deficits to develop models of cognitive functions.
• What type of studies does Cognitive Neuropsychology primarily look at?

  Case studies of patients with brain lesions.
• What does Cognitive Neuropsychology examine in patients?

  It examines what tasks patients are impaired at and what they can do.
• What are some ways of acquiring brain damage?

  Neurosurgery, strokes, traumatic head injuries, tumors, viral infections, and neurodegenerative disorders.
• Why might patients undergo neurosurgery?

  In the absence of pharmacological treatments, especially in cases of severe epilepsy.
• How do strokes lead to brain damage?

  By disrupting the blood supply in the brain, causing death of neurons.
• What is the most common form of brain injury in people under 40?

  Traumatic head injuries.
• What causes tumors in the brain?

  Tumors are formed when new cells are produced in a poorly regulated manner.
• How do viral infections affect the brain?

  Viruses target cells in the brain, such as Herpes Simplex Encephalitis and HIV.
• What is the impact of neurodegenerative disorders on the brain?

  They increase with life expectancy and include conditions like Alzheimer’s and Parkinson’s disease.
• What can single case studies provide in Cognitive Neuropsychology?

  Valid data to test and develop cognitive theories.
• What does the term "Agnosia" mean?

  Agnosia means "without knowledge".
• What is Visual Agnosia?

  It is an impairment in the ability to recognize visual objects despite intact sensory input.
• How does Visual Agnosia affect object recognition?

  Patients have difficulties recognizing objects despite having normal visual acuity.
• Who conducted the case study of Dr. P?

  Oliver Sacks in 1985.
• What did Dr. P struggle to identify in his case study?

  He struggled to identify objects and their functions.
• What is the name of the test used to assess matching functions?

  The Matching to Function test.
• What are the two basic forms of Agnosia according to Lissauer?

  Apperceptive and Associative Agnosia.
• What characterizes Apperceptive Agnosia?

  It involves problems with percepts and forming stable representations of objects.
• What is a key feature of Associative Agnosia?

  Patients have a normal percept but cannot attribute identity to objects.
• How do the modern accounts of Agnosia differ from Lissauer's account?

  They include additional levels such as shape/feature coding and semantic knowledge.
• What is the significance of the Efron Shape Matching test?

  It assesses whether patients can match basic shapes, indicating intact shape coding.
• What is the debate surrounding Pseudoagnosia?

  Whether failures to perceive shapes should be classified as agnosia.
• How did DF's condition affect her ability to use shape?

  DF could not match shapes but could use shape to guide her actions.
• What was DF's ability regarding object sizes?

  DF could not discriminate between sizes but could accurately pick up objects.
• Why is DF's case significant in understanding visual processing?

  It shows a dissociation between perception and action in visual processing.
• What are some problems in identifying objects?

  Brightness discrimination, colour, acuity, orientation
• What is the debate surrounding pseudoagnosia?

  Whether failure to perceive a shape should be classified as agnosia
• Who supports the classification of shape perception failure as agnosia?

  Humphreys and Riddoch
• Who opposes the classification of shape perception failure as agnosia?

  Warrington
• What does Warrington argue about shape coding?

  Shape coding is sensory
• What condition did DF suffer from?

  CO poisoning leading to posterior cerebral lesions
• What was DF's performance on the Efron Test?

  DF failed to match basic shapes
• What could DF do despite her shape perception impairment?

  Use shape to guide action
• How did DF respond when shown a slot?

  She could not describe its position or rotate her hand to match it
• What could DF do with her hand or card in relation to the slot?

  She could place her hand or card into the slot
• What does DF's ability to calibrate hand movements indicate?

  She 'knew' about orientation
• How did DF perform in discriminating between blocks of different sizes?

  DF was unable to discriminate between sizes
• How did DF manage to pick up objects accurately?

  With a gap between her finger and thumb reflecting the object's size