Neuro Chapter 5 Keywords

Spectrotemporal analysis

the computation of which sound frequencies are modulated at which rates over time

Phonological neighborhood density

the size of a given word’s network of similar-sounding words

Wada Procedure

a way to temporarily shut down an entire hemisphere by injecting sodium amobarbitol into either the left or the right carotid artery

Word Deafness

a disorder in which speech perception is impaired, despite intact hearing and sometimes even intact recognition of nonspeech sounds

lemma

an abstract word node that not only intervenes between semantics and phonology, but also specifies grammatical information (eg: cat is a count noun that can be either singluar or plural)

The ventral stream

the “what” stream; from sound to meaning (comprehension)

The dorsal stream

the “how” stream: from sound to action (motor)

verbal short-term memory

a memory system that allows a person ot keep words in an active state for a relatively short period of time

digit span task

a task that measures a person’s verbal STM capacity by determining the longest string of arbitrary digits that they can repeat correctly

Dorsal Plane (temporal lobe)

Where spectrotemporal processing begins

STG (dorsal/lateral)

site of phonetic processing

Mid-posterior STS

site of word form recognition

Hierarchial organization

phonetic features to phonemes to syllables to words; shaped by prior knoweldge too

Bilateral organization

early speech processing occurs in both hemispheres, mild left bias

AST Hypothesis

left = fast signals (20-80ms, place of articulation) Right=slow signals (150-300ms, syllabic stress)

Double dissociation evidence

brain-damaged patients: comprehension vs repetition/monitoring separated

Lexical Interface

contains lemmas; maps sound to meaning/syntax; located in pMTG (bilateral, left bias)

Combinatorial network

derives phrases/sentence meaning; located in a MTG + ATL, left-dominant; mainly semantic

Dorsal Stream Functions

repetition, verbal STM, motor-simulation-aided perception

Sensorimotor interface

Relay: sound-motor representations; located in area Spt

Articulatory network

underlies speech production; located in left frontal lobe