PYB304 Behavioural Neuroscience - Language and Aphasia Lecture Notes

Flashcards on Language and Aphasia

Aphasia

Loss of language processing ability after brain damage.

Broca's aphasia

Non-fluent, expressive aphasia characterized by major disturbance in speech production, loss of pronouns, articles and intact comprehension

Wernicke's aphasia

Fluent, receptive aphasia characterized by major disturbance of auditory comprehension, fluent speech, normal rate, rhythm, intonation as well as poor repetition and naming

Conduction aphasia

Failure to repeat, paraphasias (phonemic)

Transcortical sensory aphasia

Disconnection of auditory and concept centres; damage to tracts in temporo-parietal-occipital junction

Transcortical motor aphasia

Disconnection of concept centre from motor and auditory language centers, lesion to tracts superior and/or anterior to Broca’s

Phonology

Sounds that compose language and the rules that govern their combination

Phoneme

Smallest unit of sound that can distinguish one word from another

Allophone

Different representations of the same phoneme

Phonetics

How phonemes are produced in different contexts through the use of the international phonetic alphabet

Semantics

Words and their meaning

Syntax

Methods for combining individual words to convey propositional meaning

Agrammatic aphasia

A graded impairment in which both production and comprehension are impaired

Broca's Aphasia (Classical)

Poor speech production

Wernicke's Aphasia (Classical)

Poor speech comprehension

Anterior lesions (Psycholinguistics)

Syntactic processing

Posterior lesions (Psycholinguistics)

Semantic processing

Dysarthria

Disturbance of speech musculature in terms of speed, strength, steadiness, coordination, precision, tone, and range of motion

Apraxia of Speech (AoS)

Impairment in the ability to program speech movements

Alexia

Impairment in the ability to read

Agraphia

Impairment in the ability to write

Phonological route to reading

Convert letter strings to sounds to understand the meaning (grapheme-to-phoneme)

Direct route to reading

Printed words are directly linked to meaning in a visual form system

Surface Alexia

Read by sound, using grapheme-to-phoneme conversion; difficulty with irregular words

Phonological Alexia

Able to read previously learned words (regular or irregular) via the direct route, but difficulty reading new words and nonwords

Deep Alexia

Semantic substitutions, influence of “imageability” of word, visual errors, damage to both direct and phonological routes

Central Dysgraphia

Problems accessing orthographic information from lexical stores or from applying sound-to-spelling phonological rules

Peripheral Dysgraphia

Reflects distortions in written letter formation, oral spelling or typing (motor programs)

Wundt's Model

A central attention “apperception” system located in the frontal cortex controls a word production and perception network centered around perisylvian cortex

Linked attention systems

System that monitors conflict in information processing, and a compensatory control system that is engaged when conflict is detected related to speech production

ACC

The anterior cingulate cortex which is activated by vocal, manual and oculomotor tasks involving conflict

Lichtheim (1885) Model

Models of word meaning proposing abstract or amodal representations distributed throughout the cortex.

ATL models

Distributed-plus-hub models proposing a key role for the anterior temporal lobe (ATL) in mediating amodal conceptual representations

Dorsal pathway

Interfaces sensory/phonological networks with motor-articulatory systems (arcuate fasciculus)

Ventral pathway(s)

Interfaces sensory/phonological networks with conceptual-semantic systems (inferior fronto-occipital fasciculus, uncinate fasciculus)

Grounded language models

Propose word meaning is represented in the same sensory or motor structures responsible for mediating perception and action

Mirror neurons

Premotor area F5 containing a class of visuomotor neurons that respond congruently when goal-directed mouth or hand actions are both observed and executed