Notes:

Exam corrections – due on Thursday, November 12

Last Exam

Concrete vs Abstract words

22

“Language”

Human Neuropsychology (486 / 686)

Lecture Chapter 19

.

Components of Language

The Production of Sound

Origins of Language

Vocalization theories - precursors of language were animal vocalization. (poo-poo, bow-wow, yo-he-ho, sing-song)

Gestural Theory – Primitive gestures evolved into language

Multimodal Theory – gestures and vocalizations evolved together

A Theory of Language

Core skills for language:

1. Categorization

2. Label categories

3. Sequence behaviors

4. Mimicry

The Localization of Language

Anatomical Areas :pSTP

aSTP

Wernicke Geshwind Model

Localization of Language

Primary auditory Visual

areas

parietal

Electrical stimulation – generally confirms roles of classic speech areas, adds primary motor and somatosensory areas and supplimental motor area (prefrontal)

Transcranial Magnetic Stimulation (TMS) – generally confirms electrical stimulation studies but suggests additional role for Broca’s area

Imaging – fMRI: many areas activated

PET: specific areas active for specific tasks

Mapping Speech Zones:

Mapping Speech Zones

Confirm roles of anterior / posterior speech zones

Posterior speech zone: analysis of auditory input

Additional role for Broca’s areaLanguage maps onto primary sensory areas

Disorders of Language

Aphasia - Disorder of speaking, writing (agraphia), or reading (alexia) that does not result from loss of sensory input, muscle paralysis or intellectual impairment

Why is studying language complex? 1. Widespread areas of the brain

contribute to language

2. Most studies of language disorders involve patients with damage to the Middle Cerebral Artery

3. Language deficits after a stroke are severe at first, but recover over time

4. Aphasias have many symptoms and causes

Disorders of LanguageThree Main Categories of Aphasia

Fluent Aphasias:

Wernicke’s (Sensory) AphasiaTranscortical mixed Aphasia (isolation

syndrome)Conduction AphasiaAnomic or Amnesic Aphasia

Nonfluent Aphasias

Broca’s or Expressive aphasia

Transcortical Motor Aphasia,

Global Aphasias

Cortical Components

Fluent Aphasias:Core deficit is Lack of

speech

comprehension -

temporal regions around

Wernicke’s

Non-fluent Aphasias:

Five symptoms – 1. Speech Apraxia - insula

2. Sentence comprehension

- superior temporal gyrus

3. Speech repetition - arcuate fasciculus

4. Working memory

5. Articulation Broca’s area

Pure Aphasias

Alexia - Inability to read (left temporooccipital)

Agraphia - Inability to write (left inferior parietal)

Word deafness - Cannot “hear” or repeat words (superior temporal gyrus)

Subcortical Components of Language

Basal GangliaImportant for speech articulation

ThalamusInfluences language by activating the cortex

Right Hemisphere Contributions to Language