LBM Midterm Flashcards

Merleau-Ponty quote

Subject and world are inseparable: each defines the other. The course's central premise.

Living

Sense-making in precarious conditions: creating a world of relevance in order to persist.

Knowing

Effective adaptation that lets an organism's lineage persist. Even an amoeba "knows."

Cognition

Embodied action directed toward something missing (intentional) that keeps the organism going.

What a nervous system adds

It links distant body parts and sensors to motor cells, expanding cognition, but it is still operationally closed.

Operational closure

Each nervous system state is set by the previous one. The world can only perturb it: we enact a world rather than represent one.

Speaking

Embodied, goal-directed communication that keeps us going as social beings. NOT a code mapping an independent reality.

Effability

Whether experience can be put into words. Wittgenstein: "The limits of my language are the limits of my world." (e.g., describing the taste of coffee)

Five biological features of language

Species-specific, species-general, ontogenetic, has a critical period, has unique brain correlates.

Species-specific

Only humans have full language. Apes reach a 2-year-old's level: meaning pole intact, formal pole (syntax etc.) undeveloped.

Apes vs. children

Apes: here-and-now, no syntax, need training, rarely ask questions. Children: displacement, syntax, no training, frequent questions.

Species-general

All humans acquire full native language by about 12, regardless of intelligence, unless severely brain-damaged.

Ontogenetic process

Language isn't taught; it emerges during maturation on a similar schedule across languages.

Critical period

About 18 months to early puberty. After that: accent and imperfect complex syntax.

Lateralization

The hemispheres specialize; language is usually in the LEFT. Unique to humans.

Contralateral organization

Each hemisphere handles the opposite side of the body: right ear -> left hemisphere, giving a right-ear advantage for language.

Handedness and language

Right-handers: 96% left-hemisphere language. Left-handers: 70% left, 15% right, 15% bilateral.

Left vs. right hemisphere

Left: words, syntax, math, analysis, writing. Right: metaphor, music, spatial, emotion, faces.

Right hemisphere and language

Handles metaphor/figurative meaning (more right activation for metaphors) and some auditory language processing.

Split-brain experiment

KEY|RING flashed: the patient says "ring" (left hemisphere) while the left hand picks a key (right hemisphere): speech is left-lateralized.

Sylvian fissure

Separates the temporal lobe from the frontal and parietal lobes. Language areas surround it (perisylvian network).

Broca's area

Left inferior frontal gyrus, BA 44/45, next to the motor cortex.

Wernicke's area

Posterior superior temporal gyrus, BA 22, near the auditory cortex.

Wernicke-Geschwind model

Auditory cortex -> Wernicke's (comprehension) -> arcuate fasciculus -> Broca's (planning) -> motor cortex.

Arcuate fasciculus

Fiber tract linking Wernicke's and Broca's areas. Robust in humans, reduced in chimps; damage causes conduction aphasia.

Broca's aphasia

Nonfluent, agrammatic, telegraphic speech; comprehension fairly good; aware of the deficit. Frontal lesion (BA 44/45).

Wernicke's aphasia

Fluent but empty speech, paraphasias, poor comprehension, unaware of the deficit. Lesion in BA 22.

Conduction aphasia

Fluent, good comprehension, POOR REPETITION. Arcuate fasciculus lesion (BA 40-44 area).

Transcortical motor aphasia

Nonfluent (poor initiation), good comprehension, GOOD repetition. Lesion anterior/superior to Broca's area.

Transcortical sensory aphasia

Fluent, poor comprehension, GOOD repetition. Posterior temporal lesion (BA 37).

Mixed transcortical aphasia

Nonfluent and poor comprehension, but repetition still good.

Global aphasia

Little or no speech; everything impaired. Large left perisylvian lesion.

Anomic aphasia

Word-finding/naming trouble; fluent, with good comprehension and repetition.

Paraphasias

Speech errors: literal/phonemic (wrong sounds) or verbal (wrong words).

Echolalia

Automatic repeating of others' speech; seen in the transcortical aphasias.

Word deafness

Hearing intact, but speech comprehension badly impaired.

Globalization of aphasic syndromes

The same deficit arises from many lesion sites: language is distributed, not neatly localized.

Dronkers et al. 2004

Sentence-comprehension study of aphasics: MTG damage was worst; Broca's area wasn't crucial for comprehension.

Middle temporal gyrus (MTG)

Key for language comprehension.

Supramarginal gyrus

Linked to semantics (per class notes).

Language network

Many left perisylvian regions (IFG, STG, MTG, angular and supramarginal gyri), not just Broca's and Wernicke's areas.

Primary progressive aphasia (PPA)

Gradual language loss from neurodegeneration (e.g., Alzheimer's). Variants: PNFA, SD, LPA.

PNFA (progressive nonfluent/agrammatic)

Effortful, nonfluent speech like Broca's plus articulation problems. Left IFG/insula atrophy; tau pathology.

Semantic dementia (SD)

Fluent speech with semantic errors; poor comprehension; repetition intact. Anterior temporal atrophy; like Wernicke's.

Logopenic progressive aphasia (LPA)

Fluent with word-finding pauses and phonological errors; poor complex comprehension. Temporoparietal; often Alzheimer's.

Semantic dementia naming over time

Errors go from specific to general: swan -> duck -> bird -> animal.

Patient AA

Her art flourished as PNFA progressed: loss of language alongside enhanced visual creativity (right parietal gain).

Ventral stream

"What" pathway: semantics, simple syntax, comprehension.

Dorsal stream

"How" pathway: phonology, repetition, articulation, complex syntax.

Dual-stream model

Dorsal = sound -> articulation; ventral = sound -> meaning; extends into the right hemisphere.

Syntax in the brain

Anterior STG and IFG.

Discourse coherence (Kuperberg 2006)

Moderately coherent stories activate both hemispheres most, because they demand inferencing.

Action words (embodied semantics)

Reading kick/grasp/lick activates the leg/hand/face motor areas: meaning is grounded in the body.

Neuron structure

Dendrites -> cell body -> axon (myelin, nodes of Ranvier) -> neurotransmitters; signals via action potentials.

PET

Positron emission tomography: a radioactive tracer tracks blood flow. Shows WHERE, not when.

fMRI

Measures blood-oxygen changes. Good localization, poor timing.

EEG / ERP

Electrical brain activity measured in milliseconds; an ERP is the response to a stimulus. Shows WHEN.

ELAN

~150 ms, early left anterior negativity: phrase-structure violations ("The blouse was on-the ironed").

LAN

Left anterior negativity to syntactic violations; a different scalp map from the N400.

N400

~400 ms: semantic anomaly ("The cats won't BAKE"). = MEANING.

P600

~600 ms: syntactic violation/reanalysis ("The child throw the toys"). = FORM.

Semantic-reversal P600

"The eggs would EAT" -> P600, not N400: role reversal is processed as syntax.

N400 in low comprehenders

Reduced and delayed: slowed processing.

Brain vs. mind

Brain = physical substrate; mind = psychological experience.

Rationalism

Knowledge comes from innate reason; universals (Plato, Descartes; today Chomsky).

Empiricism

Knowledge comes from sensory experience; diversity (Aristotle, Locke, Hume; today Geertz).

Geertz

Modern empiricist: understand humanity through particular cultural detail.

Chomsky (rationalist)

"Ideal speaker-hearer"; UG is common to all humans; variation is marginal.

Key question of innateness

What lets all humans acquire language, and what do we have that apes lack?

babies and chimps intention-reading

Humans constantly read intentions; chimps don't, and don't point. Babies follow gaze by 5 months.

Brain growth (humans vs. chimps)

Human brain ~25% of adult size at birth vs. chimp ~50%: long, socially immersed development.

kids vs apes on social cognition

Kids and apes are equal on physical cognition; kids far ahead on social cognition.

White sclera

Makes human gaze visible, supporting joint attention and cooperation.

Pro-sociality

Humans are fundamentally cooperative: I + you = we.

Culture as immortality project

Culture lets shared ways outlive individuals.

Evolution of human sociality

Ape -> early human -> modern human: individual -> joint -> collective intentionality.

Joint intentionality

Shared goals between two people (I + you = we); e.g., pointing.

Collective intentionality

Group-level shared goals and norms (nations, subcultures).

Learning to tango

Walking -> walking together -> tango: development builds on joint and collective skills.

Emulative learning

Copying an action for a result without grasping intent (correlation). Chimps and toddlers do it.

Imitative learning

Grasping the intent behind an action and reproducing it (causation); e.g., pointing. Uniquely human; needed for language.

Language as externalization

Language externalizes intentions.

Essentialism

We are born with innate, domain-specific modules for categorizing the world (against the blank slate).

Four naïve theories

Psychology (ToM), physics, biology, sociology.

Naïve physics

4-5-month-olds know solidity and cohesion (no teleporting); animals do too, so it's innate.

Naïve physics experiments

Infants look longer at impossible events (violation of expectation).

Naïve biology

Universal folk taxonomy: plant > tree > oak > white oak > swamp white oak.

Theory of Mind (ToM)

Knowing others have minds that may differ from mine. Its absence in autism = "mind blindness."

False belief test (Smarties): they put pencils in smarties box

Age 3 says others will think "pencils"; age 5 says "Smarties."

Referential communication tasks

Child must give enough information or take the adult's view (e.g., a hidden glass). Mastered around 7-9.

Levels of Theory of Mind

L1 "I know you know" (lying; apes, 5-month-olds); L2 kidding; L3 negotiating; L4+ only humans, by the early teens.

ToM and language

ToM development correlates with the critical period; culture rests on higher ToM levels.

Universal Grammar (UG)

Chomsky/Pinker: innate language knowledge, a "language instinct."

Joan appeared/appealed to Moira

"herself" = Joan (appeared) vs. Moira (appealed): subtle knowledge claimed to be innate.

Auxiliary fronting

"Will the boy who can swim win?" never "*Can the boy who swim will win?": structure dependence.

Item-based schemas

Kids generalize from frames (Can I VP? -> AUX NP VP?): grammar can be learned.

Poverty of the stimulus

Input is too thin to learn grammar, so there must be an innate Lang. Acq. Device (LAD).

Language Acquisition Device (LAD)

Hypothesized innate, language-only learning mechanism.

Rebuttal to poverty of the stimulus

Empirically false: by age 4 a child hears 6M+ utterances and ~10k questions.

Information encapsulation

Each mind module works independently; language depends on no other skill.