Language (neuro)

Question 1

What is language?

Answer 1

• A system for representing, communicating information about the world using symbols and rules
• Natural language vs. ‘formal’ languages:
  • Formal languages = finite systems of signs and rules for combination
• Human language vs. animal languages:
  • Bees, primates, cetaceans
  • Closed / finite vs. generative
  • Capable of representing abstract concepts

Question 2

Language groups

Answer 2

• ancestral language -> regional dialects -> modern language ‘families’

Question 3

Functional components of language (articulation)

Answer 3

• articulation (phonetics)
• Movement of the tongue, lips and jaw to modify a sound wave
• Classified by place of articulation
  • Labial
  • Alveolar
  • Palatal
• …and by manner of articulation
  • Voiced vs. unvoiced
  • Fricative, plosive etc.

Question 4

Functional components of language (phonology)

Answer 4

• The sound combinations from which the syllables and words of a language are built up
• ‘Legal’ phonological structure varies across languages
• The International phonetic alphabet (IPA) is used as a common notation

Question 5

Functional components of language (meaning)

Answer 5

• meaning (semantics)
• The representation in long term memory of concepts and the
  relations between them
• Actions, objects, properties -> verbs, nouns and adjectives
• Largely independent of grammar
• Mapping between concepts and symbols generally arbitrary
  • though nb onomatopoeia – e.g. ‘hiss’

Question 6

Functional components of language (syntax)

Answer 6

• The arrangement of words and phrases to create well-formed sentences in a language
• Relies on grammatical markers and word order
• In English, word order (SVO) is paramount in assigning role: S V O S V O
  • The dog bit the man vs. The man bit the dog
• Other languages rely on ‘markers’ of word role:
  S V O O V S
  • Canis morduit hominem vs. Hominem morduit canis

Question 7

Functional components of language (comprehension)

Answer 7

• The ability to represent the meaning of words or sentences spoken or written by another person
• Entails knowledge of 1 – 4, but also:
• Context:
  • ‘I reached the bank’
• Pitch:
  • shī shì shí shî
• Stress:
  • ‘Do YOU live here?’ vs. ‘Do you LIVE here?’ vs. ‘Do you live HERE?’
• Prosody:
  • ‘Woman! Without her, man is helpless’ vs. ‘Woman, without her man, is helpless’

Question 8

Broca’s aphasia

Answer 8

• Difficulty with articulation and phonology
• Speech: Halting, fragmented, distorted, agrammatic
• Comprehension: Preserved for words; reduced for sentences
• Follows damage to: Broca’s area
• Typical pathologies: Middle cerebral artery infarction; haemorrhagic stroke

Question 9

Wernicke’s aphasia

Answer 9

• AKA ‘Receptive aphasia’ or ‘sensory aphasia’
• Speech: Fluent, often with meaningless phonological strings
• Follows damage to: posterior regions of language network
• Typical pathologies: penetrating brain injury; cerebral haemorrhage

Question 10

Conduction aphasia

Answer 10

• Difficulty with repetition
• Speech characteristics
  • Mild fluency and comprehension difficulties
• Test
  • single word and sentence repetition
• Follows damage to
  • posterior perisylvian regions and underlying white matter
• Typical pathologies
  • lacunar stroke

Question 11

Dynamic aphasia

Answer 11

• Difficulty planning, initiating or maintaining speech
• Speech characteristics
  • Reduced, fragmentary, echoic, perseverative speech
• Test
  • High vs. low constraint sentence completion
• Follows damage to
  • Anterior left inferior frontal gyrus (BA 45)
• Typical pathologies
  • Left anterior cerebral artery infarction

Question 12

Language change after brain damage: stroke

Answer 12

• Broca’s aphasia
• Wernicke’s aphasia
• Conduction aphasia
• Adynamic aphasia

Question 13

Language change after brain damage: neurodegeneration

Answer 13

• Nonfluent progressive aphasia
• Fluent progressive aphasia
• Logopenic progressive aphasia

Question 14

Non-fluent progressive aphasia

Answer 14

• Slow, distorted, agrammatic speech production
• Begins with subtle changes – progressive course
• Phonological and grammatical errors in spontaneous speech
• Single word comprehension well preserved
• Difficulty understanding sentences
• Typical pathology
  • Primary tauopathy [FTD-Tau]

Question 15

Fluent progressive aphasia

Answer 15

• Normal sounding speech rate and production empty of content
• Begins with subtle word-finding changes
• Generic word and pronoun use spontaneous speech
• Profound single word comprehension difficulties
• Location of pathology
  • Anterior temporal regions
• Typical pathology
  • TDP-43 proteinopathy [FTD-TDP]

Question 16

Logopenic progressive aphasia

Answer 16

• Begins with subtle word-finding changes
• Poverty of speech output
• Occasional errors in syntax and phonology;
  poor sentence repetition
• Posterior perisylvian pathology
• Typical pathology
  • Alzheimer’s disease