Cognitive Neuroscience 2 Flashcards
What evidence do we have that grammar (Syntax) is important and unique to language?
We can assess grammar even when meaning is lost (Jabberwocky)
Animals can’t learn it
What is recursion?
Embedding linguistics units within each other to make a sentence
What is a constituent?
Words/phrases that can operate as a single unit in a hierarchical structure
How do we parse sentences?
Identify local phrase structure through word category information
Compute syntactic and semantic relations by assigning thematic roles
What is the extra step taken in parsing ambiguous sentences?
The integration of context
What is a garden path sentence?
A grammatically correct sentence that starts in a way that means a reader’s first interpretation will probably be wrong
What is a serial parsing model?
A model that suggests that the parser maintains one structure and then, if it is wrong, starts parsing the sentence again, accommodating the new information
What is a parallel parsing model?
Parser maintains all possible structures and discards as new information becomes available
What is an encapsulated parsing model?
The parser only uses syntactic information (bottom-up), frequency and prosody
What is an interactive parsing model?
Parser uses lots of information including syntax, context, discourse, and visual information (bottom up and top down)
What can ambiguity tell us about how we parse sentences?
Tells us our preferences in how we interpret sentences – suggests not all sentences are considered in parallel
May tell us how we handle unambiguous input – reaction times and eye movement tech as well as EEGs for auditory parsing
What is the garden-path model?
Immediate, serial, encapsulated
Each word added to current syntactic structure, only one structure maintained at a time
Processing difficulties occur at points of ambiguity when preferred analysis disproved
Initial analysis only guided by syntactic info
What is the two-stage model?
input > lexical processor > syntactic parser > syntactic structure > thematic interpreter > sentence meaning
context info only influences at a later stage
What are some of the heuristics that cause garden path sentences?
Late closure – attach new parts of a sentence to a phrase/clause that is currently being processed rather than starting a new one
Minimal attachment – attach info to the phrase structure with the fewest nodes
What are the characteristics of constraint-based models?
Immediate, parallel, interactive
Each word processed immediately
Multiple structures are maintained and ranked according to how well they fit constraints
All information types used to aid analysis – context, visual context, frequency of syntactic structure, syntax, prosody, word meanings
What have eye movement studies shown us?
How garden path sentences affect parsing
When you reach the ambiguous section of the sentence, you have to go back and start it again to reinterpret what you read before you can continue reading
How does the frequency of syntactic forms affect parsing?
If a word is most commonly used in one syntactic form, you are most likely to parse it that way which can lead to garden path sentences in the long run
What is a P600 and when does it appear?
positive spike in ERP 600s after a syntactic anomaly e.g. a garden path sentence
also by morphosyntactic errors e.g, wrong ending/SVO disagreement
What is an ELAN?
Early Left Anterior Negativity
100-200ms after syntactic anomly occurs
specifically when it’s impossible to build a phrase structure/word-category errors
more temporal
Where does a P600 occur?
not lateralised
more parietal/frontal
What do brain scans tell us about ELANs?
They correspond to the point in parsing when a phrase structure is built
How has sign language been useful for brain scans?
confirmed findings about N400, P600 and ELANs
also right anterior negativity though which is unusual
Can we use ERPs to understand whether sentence parsing is serial or encapsulated?
The fact that the ELAN comes before the N400 could suggest that syntax comes first
What happens if a sentence contains both a word-category violation and a semantic one?
Only an ELAN is observed, no N400
a word that doesn’t doesn’t make syntactic sense doesn’t quality to be evaluated on semantic grounds
isn’t lexically integrated
What happens if a sentence contains both a word-category violation and a semantic one and ps are told to focus on semantics?
N400 is restored and P600 is much bigger
suggests that P600 can be an interaction between syntactic and semantic information
What areas have neural correlates of sentence processing implicared?
posterior MTG (medial temporal gyrus) anterior STG (superior temporal gyrus) posterior STS (superior temporal sulcus) middle frontal gyrus pars orbitalis IFG (inferior frontal gyrus)
What is the relationship between Broca’s area and agrammatism?
Patients with Broca’s aphasia have impaired syntactic processing aka receptive agrammatism
rarely use function words
impaired processing of agents in complex sentences
struggle with pronouns in different word orders
Which type of sentence did Broca’s and conduction aphasics struggle most with?
Object cleft
When college students were tested on sentence comphrehension with compressed, low pass sentences, what happened? What did this indicate?
They showed results similar to those of Broca’s/conduction aphasics (very low performance on object cleft sentences)
suggests that Broca’s/conduction aphasics may struggle with those types of sentences because of demands on cognitive resources
What caused increased activation in the Left Anterior Temporal Lobe?
more specific concepts when syntax was the same
also at the onset of adjectives
How did the vmPFC respond to adjectives?
activation 200ms after onset
What are the symptoms of amnesia due to hippocampus damage? What is a case study of this?
profound memory loss
intact faculties and intelligence
Clive Wearing
What areas did Clive Wearing suffer damage?
left and right temporal lobes
hippocampus - both sides
left frontal - causes excessive repetition, highly emotional behaviour
What types of learning are spared in amnesia?
perceptual-motor skills (mirror reading)
classical conditioning (learn to avoid aversive stimuli)
priming (prior exposure affects performance subconsciously)
What is aterograde nmnesia?
amnesia where you have lost your long term memories but still have short term memory up until a certain point
What is retrograde amnesia?
Where you’ve lost your short term memory but can still remember things from the past (can’t remember what happened just before you got amnesia but can remember things from your past)
What are the subsystems of long-term storage? What can these be broken down into?
explicit (declaratice) memory - episodic and semantic
implicit (non-declarative) memory - procedural, priming, conditioning
What are the dissociations between episodic and semantic memory?
anterograde amnesia involves a loss of both episodic and semantic memories from the onset of the amnesia
retrograde amnesia invoves the loss of episodic memory but the retention of semantic memory (general knowledge)
What are the effects of early hippocampal damage?
striking episodic memory damage - can’t remember big things that happened in their lives
semantic memory is spared - reading, vocab
STM intact for recent info - digit recall, pics, stories
Explain the theory about semantic memories being retained better rather than there being a double dissociation
semantic memories are retained better because they are stronger - semantic info is reinforced a lot more than episodic (which by nature only happens once) so maybe that’s why they’re retained better and not because of separate encoding methods
What was Tulving’s rebuttal to the theory that semantic memories are retained better because they are stronger?
He used the case study of KC who could remember the difference between stalagtites and stalagmites but couldn’t remember an accident at a coal manufacturing plant that had caused his whole town to evacuate
surely second memory should be stronger because of emotional salience?
What are the symptoms of semantic dementia?
loss of semantic memory - struggle with naming and using objects, picture matching
episodic memory is intact and so is working memory and problem solving
autobiographical info is spared but non-specific but doesn’t remember them as objective historical events, only in the way they were personally affected
What cortical areas show damage in semantic dementia?
atrophy to anterior temporal lobe
bilateral but worse in left hemisphere
Where does episodic memory seem to be localised?
the medial temporal lobe
Where is content localised in episodic memories?
verbal - left hippocampus
visual - right hippocampus
Where is content localised in semantic memories?
living/non-living - temporal lobe
fruit veg vs anmals - occipitotemporal
tools/actions - premotor/parietal
What evidence is there that the MTL is important for encoding episodic memories?
items that ps remember correctly are associated with greater activity in the MTL during encoding
What evidence is there that the MTL is important for retrieving episodic meories?
researchers tried to use hippocampal activity to figure out waht stimulus the participants were thinking about
could decode it about chance (~45% to 33%)
What evidence is there that anterior temporal lobe is important for semantic memories?
when ps had to access info about tools, anterior TL activated
What do we know about the storage of semantic memories?
Semantic memories are clustered all over the cortex in different categories although anterior TL may be important for accessing (the hub)
Huth et al 2012
Explain the theory that suggests that rather than an episodic/semantic dissociation, there is a distinction between specifics and generalities
Hippocampus separates info, neocortex integrates it
want memory system to remember specifics and generalities about the world - stable and plastic
hippocampus remembers specifics, neo puts those specifics together to extrapolate general rules about the world
What is the contrasting pattern of memory loss in people with semantic dementia and people with amnesia and what does it suggest?
amnesia - not complete retrograde loss of EMs, just most recent ones
case study PZ
reverse in patients with semantic dementia - increased EMs for closer things and loss of memories from further back
newer episodic memories reliant on MTL, esp newer ones
suggests that info gradually transferred from hippo to neo
older memories ‘semanticised’ - almost like a 3rd person memory
What types of information (apart from memory) is the hippocampus associated with?
spatial info - Maguire taxi drivers, place cells
amnesic patients have poor spatial orientation usually
novel info in WM - Ranganath and Blumenfield, novel associations/objects
hippo damage leads to problems learning new associations
What is the Complementary Learning Systems theory (McClelland et al)?
Theory that suggests that hippo is in charge of fast learning
creates arbitrary links and remembes specific details
neocortex is in charge of slow learning
integrates memories and creates consistent links
extracts stable generalities
slightly different different to specifics generalities - rather than different types of content, different types of learning
How do the hippocampus and neocortex work together?
new information is rapidly stored in hippocampus and then gradually moved to the neocortex for consolidation
allows you to learn info rapidly and select what is worth keeping
What is hippocampal replay?
hippocampus replays recent experiences during offline periods e.g. rest and during these periods the hippo and neo interact
predicted by CLS
What did Takashima et al find and what is its significance for the CLS?
When you ask people to recall information that they have recently remembered, the hippocampus is activated, but when you ask them for info encoded 24h before, different areas of the cortex are activated
suggests that CLS is right and info is transferred from hippo to neo