Seeing Meaning

semantic

getting meaning from words, spoken or written

How we come to understand the meaning of semantics

Word pairs

Phrases

Sentences

Paragraphs (discourse)

Narratives

Binder meta-analysis used 120 neuroimaging studies of semantics in the brain. where were the effects most concentrated?

gestalt cortex

almost all of gestalt cortex is associated

with semantic

Combinatorial semantics

semantics with coherent integration: Word pairs, phrases, sentences (and paragraphs)

Brings together elements of words/sentences into coherent, meaningful wholes

combinatorial semantics focuses on the

meaning of multiword phrases or sentence

• The word car has a different meaning when paired with the phrase “toy car”

the meaning of individual elements (words) change

when combined

combinatorial semantics are analogous to the gestalt

combination of elements discussed in the coherence lecture

Combinatorial semantics (word pairs - 2 word pairs) task:

given 2 words, some word pairings were coherent vs non meaningful pairings

the temporoparietal cortex had a stronger response to

Meaningful combinations compared to non meaningful combos.'

• (fuzzy bottle vs plaid jacket)

The group showed that participants who had damage to the angular gyrus (gestalt)

did worse on the test in proportion to their damage. (more structural damage = performed worse)

Combinatorial semantics (sentences). compared the following type of sentences and looked at brain activity.

Semantically congruent sentences

Semantically random sentences

Pseudoword sentences

Semantically congruent word lists

Semantically incongruent word lists

How did brain regions respond to each of these 5 different types of stimuli?

the angular gyrus in gestalt was the only region that showed a differentiation peak that specifically responded to congruent sentences compared to everything else.

Other regions showed a bump for congruent sentences, but

showed the same bump up for words in a different incongruent order.

Gestalt was the only one to differentiate

coherent sentences from everything else.

What's the difference between coherent sentences from everything else?

Conscious experience of the meaning

Requires little to no effort for a native speaker of english

It's a single coherent thought-->global whole

effortless meaning making

Combinatorial semantics: paragraph. how does reading a paragraph without a title affect the meaning?

without the title its a bunch of coherent sentences but they don't seem to have any relation and it reads incoherently. with the title it gives context.

What was more active when people saw the exact same paragraph with and without the title?

Largest activation in gestalt cortex when you are given the title

how do most neuroimaging studies work?

Have people do a task: look at a series of houses → Rest→task: look at series of faces→ Rest

uses analytical procedure that would search the brain for spots in the brain(voxels), showed patterns that corresponded to a particular hypothesis

neural synchrony definition

Examines the extent to which neural fluctuations are synchronized over time between two or more people (or same person during repeated experience) in one region in the brain.

if fluctuations are highly correlated over time in the same region,

both people have strong neural synchrony.

neural synchrony shows people

naturalistic things, watching a video with no particular structure.

neural synchrony studies

long naturalistic stimuli, like narratives

Uri Hasson's brain regions showed neural synchrony in areas rather than

strength of activity

Showed people a scene from a movie from alfred hitchcock: A1- primary auditory cortex

fluctuates between loud and quiet parts of movie→Everyone synchronized on this because sound does not = meaning

overall the movie of Alfred Hitchcock gave evidence of

Strong neural synchrony throughout much of the brain,

• In a movie where a director is ensuring that everything is happening for a reason, people are unified in what they are thinking and feeling

what if you showed participants footage of Washington square park?

Not much neural synchrony at all

• In a video of just normal life at washington square park, people are having very different responses

what about a silent film? response in motion cortex showed

Neural synchrony across participants

Hasson cut the Charlie Chaplin movie into 2 minute segments. some people saw the correct order, others saw the incorrect order. how do they compare?

in the 2 minute segments, there was neural synchrony regardless of if you watched them out of order. could still measure based on the the input.

Hasson then chopped them into 4 second segments and randomized them. hasson could still take all the neural responses from each clip and line them up in correct order.

he could tell which region of the brain cared about the shuffling vs did not care.

early visual cortex wont care about

the clips being shuffled but parts of the brain that need coherence do care.

early visual cortex doesn't care about arc in movie so there is

Neural synchrony between short and long clips as they still saw the same clips.

neural synchrony between a person who saw the chopped video and the long clips were in the

Gestalt cortex as it makes sense of narratives and long clips

what about storytelling, how are narratives synced?

As you gain more meaning, you aggregate more neural synchrony in the gestalt cortex. meaning exists in narrative form in gestalt.

stories represented at three level:

surface level

textbase level

situation model

surface level

specific wording and syntax can change surface-level representations.

"The sun is out" and "the sun is in the sky" have different words and syntax

Textbase level

how each sentence is interpreted in terms of its underlying proposition. limited to one sentence at a time, never connected to the larger story

"The sun is out" and "the sun is in the sky" have same textbase

situation model

the coherent meaning of the narrative

What is happening across space and time, to characters and objects, what are causes behind changes.

situation model is associated with

TPJ in gestalt cortex and does not depend on effort/WM processes. It is a part of the effortless meaning making process

While surface and textbase processing worsen with age, situational model processing

does not

CEEing meaning is associated with

TPJ and angular gyrus for thematic word pairs, phrases, sentences, and narratives. same regions associated with gestalt visual perception as with meaning.

narrative also relies heavily on an area that is not in gestalt, which is the

medial parietal cortex