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Introduction to Cognitive Neuropsychology &
Cognitive Neuropsychology of Language
C81BIO
Dr. Mark Haselgrove
Overview of the lecture
(1) Introduction to Cognitive Neuropsychology
What is it?
History: (i) Phrenology & Localization(ii) Recovery of function following damage
(3) Cognitive Neuropsychology of Language
Broca’s Area and Aphasia
Wernicke’s area and aphasia
(2) Mapping the brain
Brodmann’s map
(1) Introduction: What is Cognitive Neuropsychology?
- The study of the relationship between brain function and behaviour.
- Especially as determined through evidence from damaged brains, but can include other methods (e.g. imaging).
• Missile wounds (bullets)• Tumours (cancer)• Impact (road accidents)• Surgery (intractable epilepsy)• Disease (encephalitis,
hydrocephalus, HIV)• Strokes (blocks, bleeds)
(1) Introduction: What is Cognitive Neuropsychology?
- The study of the relationship between brain function and behaviour.
- Especially as determined through evidence from damaged brains, but can include other methods (e.g. imaging).
• Missile wounds (bullets)• Tumours (cancer)• Impact (road accidents)• Surgery (intractable epilepsy)• Disease (encephalitis,
hydrocephalus, HIV)• Strokes (blocks, bleeds)
(1) Introduction: What is Cognitive Neuropsychology?
- The study of the relationship between brain function and behaviour.
- Especially as determined through evidence from damaged brains, but can include other methods (e.g. imaging).
- Aims to assign particular psychological functions to particularbrain structures (if we accept modularity of brain function).
• Missile wounds (bullets)• Tumours (cancer)• Impact (road accidents)• Surgery (intractable epilepsy)• Disease (encephalitis,
hydrocephalus, HIV)• Strokes (blocks, bleeds)
• Assumption: brain function is “localised” or “modular”, with different structures performing different roles.
• Many functions rely on distributed brain systems.
– Language, memory etc. use much of the brain.
– Brain regions are specialized to perform particular roles, but these may not map neatly onto our ideas of “brain functions”.
(1) Introduction: What is Cognitive Neuropsychology?
CAUTION!
(1) Introduction: History
- Franz Joseph Gall (1758-1828).- Johan Spurzheim (1776-1832)
- As a youth, Gall was annoyed by students with a good memory but poor original thinking…
- Recalled these students had large protruding eyes
Developed a theory of brain function:Localisation of function:
Different parts of the brain responsiblefor variations in individual differences
(1) Introduction: History
Phrenology
- People who had skills in maths, music, sense of colour combativeness, - bumps in other areas
- Depressions in skull indicate underdevelopment- Amativeness (sex drive) behind lower part of ears
Variety of people with different extreme traits examined:
Murderers (N=25)SadistsTorturers
Considered evidence from paintings and busts
(1) Introduction: History
- Used as a method of personality assessment: Cranioscopy
- The fall and ……collapse of Phrenology
- Invited quackery, and ridicule by association- Most assessments entirely subjective
- Outside of the skull does not mirror even the inside of the skull, let alone the underlying brain
Pierre Flourens (1794-1867)
“The famous physiologist, Magendie, preserved the brain of Laplace. Spurzheim had the very natural wish to see the brain of the great man. To test the scienceof the phrenologist, Mr Magendie showed him, instead of the brain of Laplace,that of an imbecile. Spurzheim, who had already worked-up his enthusiasm,admired the brain of the imbecile as he would have admired that of Laplace”
(1) Introduction: History
Flourens also conducted experiments…
Lesioned parts of the cortex of different animals: Observed how it behaved
At first: → Moved very little, refused to eat and drink
Later: → Recovery of function. To the point of appearing normal.
Pattern of loss and recovery seemed inconsistent with the assumption of localisation
However:
Lesions to: Parts of the brain stem → permanent breathing difficultiesCerebellum → loss of locomotor co-ordination (not sex drive!)
(2) Mapping the brain
- Brodmann’s Areas (BAs, 1909)
- Appearance of cortex under microscope (cytoarchitectonics)
- Should BAs map neatly onto psychological functions? - Partly, because cytoarchitectonic structure is influenced by connections.
(2) Mapping the brain
- Brodmann’s Areas (BAs, 1909)
- Appearance of cortex under microscope (cytoarchitectonics)
- Should BAs map neatly onto psychological functions? - Partly, because cytoarchitectonic structure is influenced by connections.
(3) Cognitive Neuropsychology of Language
Launched the field of Neuropsychology
Jean Baptiste Bouilaud (1796-1881)
Proposed that certain functions were localised
Physicians noted that damage to left hemisphere → impaired movement on right
Writing also disrupted…Language on the left?
Paul Broca (1824-1880)
Received a patient Monsieur “Tan” LeborgneCould only say “Tan” and utter an oath
Bouilaud’s son in law, Ernest Auburtin, reported a case of a patient who lost theability to speak when pressure was applied to the exposed frontal lobes
(3) Cognitive Neuropsychology of Language
Tan died in 1861
Autopsy revealed a lesion to the left frontal lobe:
Thus demonstrating: LateralizationLocalization
Anterior speech region = Broca’s area
Syndrome that results = Broca’s Aphasiafrom damage to this area
(3) Cognitive Neuropsychology of Language
Carl Wernicke (1848-1904)
Investigated region of the cortex that receivesinformation from the ear. Behind Broca’s area
Wenicke’s patients:
- Spoke fluently, but with no sense- Could hear, but could not understand what was said
to them
This region of temporal lobe = Wernicke’s’s area
Syndrome that results = Wernicke’s Aphasiafrom damage to this area
(3) Cognitive Neuropsychology of Language
Model of Language processing
Auditory information sent to:
(1) Wernicke’s area (Sounds → sound
images)
(2) Sound images transmitted along Arcuate fasciculus to:
(3) Broca’s area (representation of speech movements)
From here instructions sent to control mouthmuscles…..
Conduction aphasia:Consequent upon Arcuate fibres being damaged:
Comprehension maintained…and speech sounds
Speech impaired (difficulty repeating what is said to them)
Reading
Kolb, B., & Wishaw, I. Q. (2003). Fundamentals of Human Neuropsychology,Worth Publishers. Ch’s 1, 3 & 17.
Next Time: The Neuropsychology of Memory and Vision (1st May noon)
Email: [email protected]