PSYC midterm 3 Flashcards
Problem with LTM
How to acquire information from experience, maintain it over time,
and use it when relevant to guide behavior and plan future actions
Importance of LTM
In Order to change in a meaningful way we have to remember the past
Challenge of LTM
Out of all of experience, what to remember, and how to retrieve it when needed
Is learning the same thing as memory
yes
Processes involved in LTM
encoding, storage, retrieval,
Some types of LTM
semantic (facts), episodic (past experiences), procedural (how to do things)
Systems involved in LTM?
hippocampus, cortex, amygdala, ..
Tasks to study LTM:
free recall, stem completion, motor sequence learning, …
What does memory require in the nervous system
physical change
What part of the nervous system is involved in memory?
Memory is pervasive (almost every part is involved)
common underlying representation of all forms of memory?
number & strength of synaptic connections between neurons
How is STM, working memory, and sensory memory represented differently than LTM?
represented by which neurons are active at that moment and if they stop firing memory gets lost
require active maintenance
Can long term memories be passively stored
yes
Whereis the organization of storage and processing in memory located?
location of memory storage and processing coincide
How does interpretation of representations occur in LTM?
Interpretation of a synaptic weight depends on its location in nervous system (e.g. a synapse in V1 represents something visual) → where memory is is part of its meaning
What are memories accesses based on?
content (e.g. “What do you know about pandas?”) not location
What is encoding of memory in LTM?
Initial creation of memory traces in brain from incoming information → making memories
What is storage of memory in LTM?
Retention of memory traces over time
What is retrieval of memory in LTM?
Accessing/using stored information from memory traces
What is memory consolidation?
Continued organization and stabilization of memory traces over time → the way memories are initially stored may be different than how they are eventually stored
What is memory reconsolidating in LTM?
Possible reorganization and restabilization of memory traces after retrieval
after retrieval the memory can change
What are other words for short-term memory?
Working memory
Sensory memory
What are the two types of long-term memory?
Explicit (declarative)
Implicit (non-declarative)
what are the 4 types of implicit memory?
Procedural memory
Perceptual memory (priming)
Classical conditioning
Non-associative learning
What are the two types of explicit memory?
episodic memory (events)
Semantic memory (facts)
What is the Memory span test and what is it used for?
Used to test short-term memory
You hear three words and are asked to recall them in the same order
What is the list learning task and what is it used for?
Used to assess LTM
Hear ten words: “hand cook laugh …”
Immediately recall in any order: “cook train hand …”
Repeat until all 10 recalled in any order
What occurs in the list learning and memory span test for a patient with damage to the left temporoparietal cortex?
Impaired on the short-term memory task (memory span) and good at the LTM task (list learning)
What is a dissociation?
Performance differs across two task in an experiment
Can we use single dissociations to prove an argument?
NO
What is a single dissociation?
dissociated the performance on two tasks → can perform one task but not the other
What are we tempted to conclude based on single association about temporal parietal junction? Can we say this?
Short-term memory task depends on temporoparietal junction but long-term memory task does not
Therefore short-term and long-term memory are separable systems that depend on different brain regions and distinct cognitive processes
Can’t say this!!!!
What are the two alternative explanations for the results seen in the patient with damage to the left temporoparietal cortex?
- Partial damage argument
- Compensation argument
What is the partial damage argument?
Perhaps there is one system for both short-term AND long-term memory
But the short-term memory task is harder than the long-term memory task
So when this system is partially damaged the short- term memory task suffers more than the long-term memory task
What is the compensation argument?
Perhaps there is one system for both short-term AND long-term memory
But the short-term memory task is harder than the long-term memory task
So when this system is completely damaged, the brain can compensate for the long-term memory task (easier task) but not the short-term memory task
Does a single dissociation demonstrate that LTM and STM are separable systems? What do we need to determine this?
A single dissociation does not necessarily demonstrate separable systems, different brain regions, or distinct cognitive processes
A single dissociation might mean this, but to rule out alternative explanations 1 and 2, we need a double dissociation.
What is seen in a single dissociation of a patient with damage to the bilateral medial temporal lobes?
Patient can perform the memory span test (STM) but can’t perform the list learning test (LTM)
What is a double dissociation?
Two patients, Two different areas of damage
Two opposing single dissociations
What does a double dissociation show and why?
A double dissociation provides strong evidence for separable systems that depend on different brain regions and distinct cognitive processes
Suggests that short-term and long-term memory are separable systems
Short-term memory task cannot be both harder and easier than long-term memory task!
What is the timescale, capacity, and neural basis of STM?
Timescale: seconds
Capacity: extremely limited
Neural basis: sustained activation of neurons → current activation of neurons → if they stop firing the memory is gone
What is the timescale, capacity, and neural basis of LTM?
Timescale: minutes, hours, days, years
Capacity: massive
Neural basis: number & strength of synapses –> physical connections
How many words on average can a person remember in the memory span (short-term) task?
7
How many words on average does a person have in their vocabulary (LTM)?
20000
What is the perceptual identification task and what does it measure? What does it show?
Measures implicit (non declarative) memory
Study phase: 24 words presented for 2 sec each on screen
Test phase: 24 old (studied) and 24 new words flashed extremely briefly
Identify word
The words that you have been recently exposed to, you are faster at identifying
What is the word recognition task and what does it measure? What does it show?
Measures explicit (declarative memory)
Study phase: 24 words presented for 2 sec each
Test phase: 24 old (studied) and 24 new words presented until response → don’t disappear
Respond “yes” or “no” if words from study phase → explicitly asked
Can detect the words that were seen
What does the single dissociation of implicit & explicit Long-Term memory show for patients with damage to right occipital lobe?
impaired on perceptual identification task (implicit) but can do the word recognition task (explicit)
What does the single dissociation of implicit & explicit Long-Term memory show for patients with amnesia, Korsokoff’s syndrome and epilepsy?
Impaired on word recognition task (explicit) but can do perceptual identification task
Are regular people generally better at perceptual identification task or word recognition task
Word recognition
What does the double dissociation of explicit and implicit LTM suggest?
Suggest that implicit and explicit memory are distinct types of memory that depend on separate parts of the brain
What are the characteristics of implicit LTM. Is it declarative or non-declarative? Conscious awareness? Types of of implicit LTM? Timescale?
Capacity?
Neural basis?
Non-declarative → memory that you can’t describe if asked about them
Independent of conscious awareness
Procedural, conditioning, nonassociative, or priming
Timescale: minutes, hours, days, years
Capacity: massive (e.g. ~1,000s of skilled motor sequences)
Neural basis: number & strength of synapses → connections between neurons
What are the characteristics of explicit LTM. Is it declarative or non-declarative? Conscious awareness? Types of explicit LTM? Timescale?
Capacity?
Neural basis?
Declarative
Available to conscious awareness
Semantic or episodic
Timescale: minutes, hours, days, years
Capacity: massive (e.g. ~20,000 word families in adult vocabulary)
Neural basis: number & strength of synapses → connections between neurons
What does declarative mean>
if you are asked “what did you do last night” you can them
What is the difference between semantic and episodic LTM? Give an example of each.
Semantic: know facts “what is the capital of BC”
Episodic: about your own experiences “what did you do last night”
Is non-associative learning implicit or explicit?
Implicit
What is non-associative memory
A change in response to an unchanging stimulus
What are the two types of non-associative memory?
Habituation
Sensitization
What is habituation? Give an example?
Reduced response to an unchanging stimulus?
You stop noticing the busy street outside your new apartment after a while
What is sensitization?
Increased response to an unchanging stimulus
E.g.: Rubbing your arm hurts more the longer you do it
What does habituation and sensitization primarily involve?
sensory-motor reflex pathway → don’t involve higher processing in the brain
What organism was used to determine the first evidence of neural basis of memory>
sea slug Aplysia
What is a syphon?
used to pull in water and nutrients from ocean
How is the neural circuitry connecting the syphon and the gills organized inn a sea slug?
sensory neurons that are detecting touch on syphon synapse directly on motor neurons that signal the gill to contract
For habituation, what happened upon repeated siphon stimulation?
less withdrawal
What was seen regarding EPSP and AP in a sea slug experiencing habituation?
The AP from the syphon is the same
For the EPSP (excitatory postsynaptic potential) in the motor neuron of the gill were large in response to the syphon touch initially then decreased
Initially a large gill withdrawal then less
What is Pre-synaptic depression? Where is it seen?
Seen in habituation. After learning/habituation there is less neurotransmitter released for the same AP → smaller EPSP –> less gill withdrawal
For sensitization, what happens to the sea slug after it is shocked?
More withdrawal –> sensitizes the animal
What was seen regarding EPSP and AP in a sea slug experiencing sensitization?
AP are the same in the sensory neurons
EPSPs in the motor neuron are larger after
What is presynaptic facilitation? Where is it seen?
In sensitization
same action potential leading to more neurotransmitter release → larger EPSP
What did the sea slug study on habituation and sensitization show?
Showed that we can connect behavioral changes due to memory to neural changes in the brain.
Changes for habituation and sensitization happens at the synapse.
less or more release of neurotransmitter in presynaptic neuron
What are the short-term changes for habituation and sensitization? and how long do they last?
Last for minutes
Changes in amount of neurotransmitter released
What are the long-term changes for habituation and sensitization? and how long to they last
Last for hours, days, weeks
Changes in number of synapses
What happens to the # of synapses in habituation and sensitization?
More when sensitized
Less when habituated
What does conditioning involve and is it more or less complex than sensitization and habituation?
Involves the association between stimuli
More complex
What is the main study that showed classical conditioning and what did it find?
Pavlov noticed that a dog learned to salivate in response to a bell that predicted food
What happens in the classical conditioning experiment involving pavlov’s dogs?
An initially neutral conditioned stimulus (CS) comes to elicit a conditioned response (CR) due to pairing with an appetitive or aversive unconditioned stimulus (US) which reflexively elicits an unconditioned response (UR)
what is the US, CS, UR, CR in the pavlov experiment?
US = food
UR = salivation
CS = bell
CR = salivation
How does fear conditioning in a mouse work and what are the US, UR, CS, CR?
Mouse walking around in cage. Initially when you play a tone the animal doesn’t respond. After repeated pairing the tone with a shock to the animal → now if you play the tone the animal will freeze as if it is anticipating the shock
US = shock
UR = freezing
CS = tone
CR = freezing
Where does the CS and the US converge in fear conditioning? And what does the output lead to?
lateral nucleus of amygdala –> leads to fear
What does the neural circuit in fear conditioning involve?
Circuitry is between thalamus, amygdala and cortex
Thalamus is a way station that sends info up to the cortex or directly to the amygdala
What happens to the EPSP to the tone in the lateral nucleusof the amygdala after pairing it with a shock?
After conditioning, there is an increase of EPSP in the lateral nucleus of amygdala –> changes in connections between neurons
What does the dip in the graph for fear conditioning mean?
= dip in this graph of extracellular potential, since positive ions enter post-synaptic cells while leaving extracellular space → lower because we are recording outside of cells
What are the 2 types of motor skill learning (procedural memory)?
Motor adaptation
Motor sequence learning
What part of the brain is involved in motor adaptation in motor skill learning
Cerebellar loops
What part of the brain is involved in motor sequence learning in motor skill learning
Cortico-basal ganglia-thalamocortical loops
What does motor skill learning depend on?
motor system
What is the throwing darts with prism glasses measuring and what does it show?
Eye-hand coordination
Prism glasses shift visual field to side
Control participants adapt to distortion
- if they take glasses off it takes time to adjust
Patients w/cerebellar lesions fail to adapt
- if they take glasses off they can do it immediately again because they didn’t adapt
Shows that the cerebellum is required to fine tune the action based on errors → can still do the action as you know it
What model does the cerebellum use and why?
Uses forward model to predict results of motor commands
What does the cerebellum use the feedforward model for? What happens if this system is damaged?
Uses differences between actual results and predicted results for:
Online error correction
Motor learning
Feedback control
If this system is damaged, you can’t make these adaptations based on errors
What is the Serial reaction time task? and why does it measure?
Measures motor sequence learning
Sequence of light appears and you push button associated with each light → record how long it takes to press each button
Initially you are kinda slow, but if the same sequence is repeated again, you get faster
If you switch to a new sequence you are slower again
What does motor sequence learning depend on?
basal ganglia & reinforcement learning:
What occurs in reinforcement learning for motor sequence learning?
Select action expected to lead to maximum reward
Perform action
Compare actual reward to expected reward
What is prediction error?
Prediction error = actual reward – predicted reward (determines if we did worse of better than expected)
If we did better than expected then you are more likely to do that action again
What do we use prediction error for
update actions based on what will give the best reward
What represents prediction error? What occurs when something better or worse than expected occurs?
Dopamine signal from substantia nigra pars compacta (SN c) represents prediction error
Larger response (more dopamine) = better than expected
Smaller response (less dopamine) = worse than expected
What happens in the basal ganglia during reinforcement learning?
Unexpected rewards generate dopamine signals from the substantia nigra pars compacta (SNc)
This excites the direct pathway (via D1 receptors) and inhibits the indirect pathway (via D 2 receptors)
More likely that you will do the same action in the same contex
This allows modification of behavior based on reward
What is priming (perceptual representation system) and what type of memory is it?
Implicit
Change in stimulus processing due to prior exposure to same or related stimulus without conscious awareness
Exposure to a stimulus affects your later response to that stimulus
What are the three types of priming?
Perceptual priming:
Conceptual priming:
Semantic priming:
What is perceptual priming based off
How a stimulus looks
What is conceptual and semantic priming based on
meaning
You are shown the word “envelope” then asked to come up with a word that has the letters EVLP, then you will be able to come up with the envelop quickly
What type of priming is this?
Perceptual
you are shown the word envelope, then you’re asked to think of a word related to stationary → more likely to say envelope since we were recently primed with it
What type of priming is this and why?
Conceptual
Conceptual relationship between stationary and envelope → meanings are related
Having recently seen the word envelope makes up quicker to think of a related word
What type of priming is this?
Semantic priming
What is the difference between conceptual and semantic priming?
The different from conceptual priming is that the thing we are thinking of is not the same as the prime but it is related
Explain the perceptual priming experiment that uses Gollin pictures and what was found in patients with Korsakoff’s syndrome
Show fragmented pictures (Gollin figures)
Identify object in as few frames as possible
Participants improved day to day, despite not remembering the previous day’s training → how evidence of perceptual priming although they don’t have any explicit memory of doing the task
What is Korsakoff’s syndrome
Amnesia (memory deficit) due to severe alcoholism
What is the semantic priming task? What did it find?
You are presented a prime and the sequence of letters you need to judge if the sequence of letters in a word or non-word?
Sometimes the target is related to the prime
Sometimes the target is unrelated to the prime
Sometimes the target is a non-word
Having seen a related word makes us faster at identifying related words as words
Where in the brain do we see activated associated with semantic priming?
distributed throughout the cortices
What areas are involved in priming? For perpetual and conceptual/semantic priming?
Depends on region of cortex processing relevant representations
Perceptual priming: Sensory cortices (e.g. occipital lobe for vision)
Unimodal & multimodal association cortices (e.g. anterior temporal, inferior parietal, prefrontal cortex) → higher level processes areas involved
What is semantic memory and what type of memory is it?
Explicit memory
memory for facts
What areas are activates in semantic memory?
Memory for concrete word (hit, ring, red) meanings activates areas of cortex involved in relevant processing
DIfferent concrete words activate different areas of the brain
Concrete words for colours activate visual areas
Concrete words for actions activates frontal and parietal regions
Sound words activate temporal areas near auditory cortex
In semantic memory, what part of the brain is activated for action
: motor cortex/somatosensory cortex
In semantic memory, what part of the brain is activated for sounds:
auditory cortex
In semantic memory, what part of the brain is activated for colours and movement:
ventral visual stream (occipital/temporal cortex):
What are the two theories used to explain how semantic representations are distributed in the brain?
Sensory/functional theory:
Domain-specific theory:
What is the sensory functional theory?
Organization of semantic representations (meaning) is based on relevant sensory and motor features of words
Action words activate region of primary motor cortex for specific body part
Lick → face → more activation in face areas
Pick → arm → More activation in arm areas
Kick → leg → more activation in leg areas
What is the domain-specific theory?
Organization of semantic representations is based on semantic categories
E.g.:
Fruits & vegetables: Apple, orange, lettuce
Animate living things: Cat, dog, snake
Nonliving things: Wrench, hammer, rock
Conspecifics: Mom, dad, mailman
What do patients with focal brain legions show for domain-specific theory?
exhibit deficits in identifications of objects from specific categories
Is the sensory-functional theory or the domain-specific theory right? Explain why?
Both are right because Categories often correlate with sensory/functional distinctions
representations of categories may be in different parts of the brain because different categories have different sensory and/or functional representations
Tools are strongly associated with actions
E.g. hammer & hitting a nail
Premotor cortex activation
Animals are strongly associated with appearance
E.g. camel & humps
Posterior temporal cortex (ventral stream)
Tools have strong functional associations
Animals have strong visual/sensory associations
How are semantic memories formed?
They often start out as episodic memories (memory of a particular event)
At first…
What is the capital of British Columbia?
“I learned yesterday in school that it is Victoria.” → episodic memory
Years later…
What is the capital of British Columbia?
“Victoria.”
How do you know that?
“I have no idea!” → semantic memory
where is semantic memory located in the brain?
Represented across cortex organized by categories which often align with sensory or functional features
What is episodic memory?
events in our own life
How are episodic memories encoded?
Hippocampus and related (medial temporal) structures (HC) form indices (pointers) to bind cortical representations
In the memory for a halloween party and the aspect of the event is:
saw Sam dressed as Elmo
heard spooky music
ate lots of sweet M&Ms
What does the cortex represent and what does the hippocampus bind together>
Cortex represents Sam, Elmo, spooky music, M&Ms, etc… → factual representations
Hippocampus binds them together
how are episodic memories retreived?
HC and related structures use indices (pointers) to reinstantiate cortical representations
Retrieval cues are activated in the cortex, which activate pointers in HC –> these cause other representations to be activated
Representations in the cortex are activated
Episodic memories combine our semantic memory in cortex with specific event bindings in the medial temporal lobe structure
Look at the halloween example
Medial temporal lobe structures
Perirhinal cortex
Entorhinal cortex
Parahippocampal cortex
Hippocampus
Explain the flow of information in the medial temporal lobes
Unimodal and polymodal association areas in the cortex that represent meaning feed their signals into Perirhinal cortex and Parahippocampal cortex → from there the signal goes into the hippocampus
The hippocampus feeds information back up tot the cortex via the fornix
This provides a pathway for binding representations in cortex together in the hippocampus then using those bindings to reactivate individual representations in the cortex
What are the two theories that explain the role of the medial temporal lobes?
Cognitive map theory:
Relational map theory
What is the cognitive map theory and how does it work?
Hippocampus is involved in memory for spatial relationships in environment
Place cells in medial temporal lobes
Animal runs around in cage and record in medial temporal lobe while it is moving around and we record it position in the cage
Neuron fires when animal is in a particular location → create a map of this
Lets us know where we are in a familiar place
Episodic memories are usually associated with specific locations
What is the relational memory theory and explain how they tested it using the odor association task?
Memory for associations in general → create associations between things
Animal is shown 2 beakers with distinct smells and one is associated with a food reward → animal is trained to prefer certain smells
Trained to prefer:
A over B
B over C
C over D
D over E
Lesion to fornix:
If the animal was trained to prefer certain pairs and then they got a lesion → still able to choose the right one
If they are shown B and D, since they were not trained on this pair, they do not choose the right one
The control animals are able to choose the right one based on their memory because they can infer that since they like B over C and C over D, therefore they should prefer B or D
Shows that the medial temporal lobe structures and their connections to the cortex via the fornix is necessary to make associations to guide behaviour
What are the roles of the different subregions in the medial temporal lobes? (perirhinal cortex, parahippocampal cortex, hippocampus
Perirhinal cortex: Binding features of objects
Parahippocampal cortex: Encoding spatial layout
Hippocampus: Encoding relationships more generally. Information from the parahippocampus and the perirhinal cortex gets fed into the hippocampus which binds it all together to create the full image
What is hebbian learning and what is the quote that goes along with it?
“Neurons that fire together wire together”
When presynaptic action potential leads to postsynaptic action potential, connection is strengthened
Does hebbina learning allow you to recall memories
yes
What is long term potentiation?
Increase in synaptic strength
Exhibits necessary properties for Hebbian learning
Found in hippocampus (and other brain regions) → could be basis for episodic memory
LTP is synapse specific: if only the pre and postsynaptic neuron both fire we see strength increasing
What is early LTP
Increased presynaptic release of neurotransmitter
Increased number of postsynaptic receptors
Leads to large EPSP
What is late LTP?
Increased number of dendritic spines and synapses
Increases number of synapses between neurons
Purpose of long-term depression and what is it?
If synapses only strengthen, neural firing will grow out of control!
“Neurons that fire apart wire apart”?
When presynaptic action potential does not lead to postsynaptic action potential, connection is weakened
Reduction in neurotransmitter released, number of receptors, and number of synapses
Acts as a counter force to balance the amount of neural activity
Explain why episodic memory is reconstruction and not a perfect replay of our past and what it is based on.
guess based on
Memory trace → stored info
Genes
Past experience
Internal state
Environmental context
What is the DRM paradigm and what did the results show?
Presented list of semantically (meaning) related words:
Bed, rest, awake, tired, dream, blanket, doze…
Recall/recognition memory test:
Words on list (rest, tired, dream)
Unrelated distractors (cake, mountain, cloth)
Semantically-related lures (sleep)
Participants are good at identifying words on the list and good at saying words were not on list, but they falsely remember the related distractors as being on the list
Related lures reported almost as often as words actually on the list!
High confidence in accuracy
Participants often report specifically remembering presentation of lures
Happens even if you know about the effect! Unless they think about the word first
Why is episodic retrieval inaccurate?
It is reconstruction
Semantic relatedness → mistakes based on relationships of meaning
Cultural experience → remember things based on past cultural experiences
Source misattributions → if your friend told you that they saw something you won’t be able to determine what they saw vs what you saw
Pragmatic inferences → if you saw someone with a hammer at a construction site, you might remember seeing them hitting a nail, but you didn’t
Misleading postevent information → learn info after an event that is different than what really happen , it can be hard to keep that separate in memory from what really occurred
What type of amnesia does patient H.M have and why?
Removal of bilateral medial temporal lobes to try and cure epilepsy –> caused amnesia
Severe anterograde amnesia
Unable to form new LTMs after surgery
Temporally-graded retrograde amnesia
Unable to recall existing LTMs from just before the surgery → memory lost most severe for memories right before the surgery
What is anterograde amnesia?
Not being able to remember things after your surgery
Explain how consolidation works.
New memories depend on representations in cortex and links from hippocampus → if hippocampus is damaged you will lose that memory (seen in H.M) and can’t create new memories
Over time, reactivation due to retrieval and replay during sleep reduce dependence on hippocampus → create new connections in cortex
Old memories depend on representations and links in cortex, not on hippocampus → explained why H.M had old memories because it only uses cortex
What is the complementary learning systems hypothesis? Why have two memory systems (semantic and episodic)?
Hippocampus:
Learns rapidly (single trial learning) → remember party
Creates distinct memories for each event/instance
More important for episodic memories
Cortex:
Learns slowly
Extracts generalities across events/instances → for long term patterns → memories that are accessed repeatedly
More important for semantic memories
What does “new” semantic information start off as?
as episodic memory
What qualities do old autobiographical memories take on
semantic qualities
started off as episodic memories have become factual stories that are like a semantic memory
Is consolidation as permanent process?
No, can have reconsolidating
What is reconsolidating?
When a memory is retrieved, it is reformed, and is once again subject to interference
In the Fear conditioning in rats stay for consolidation, what was found and what structure did it involve?
Amygdala
Recall/reactivation leads to reconsolidation
If memory formation is blocked during reconsolidation, then the memory is forgotten!
What can happen is other events happen during reconsolidating?
, those events can get mixed in with original memory → inaccurate representation of an original event
What is language?
A systematic means of communicating information using conventionalized sounds, gestures, marks, or signals having understood meanings → doesn’t have to be spoken language
What is the goal of language?
The function of human language is to influence people’s behavior by changing what they know, think, believe, or desire.
What is the problem language is trying to solve?
How to efficiently and expressively communicate Information
What is the importance of language?
Language is the basis for society. It allows us to interact
with each other in a way that goes beyond our immediate surroundings.
What is the challenge of language?
The power of language lies in the seemingly conflicting
needs for it to be shared between people and yet capable of expressing novel ideas.
What are the powers of human language?
Communicates information quickly
Facilitates an interactive social network
Stores knowledge outside individuals → write it in books
Allows wisdom to accrue over generations → animals just teach the same thing over and over
Refers to any time or place, real or imaginary → refer to things that are elsewhere or don’t exist
Enables creative expression due to generativity and compositionality → generate new ideas
What does the hierarchial organization of language allow for?
Allows language to have a limited numbers of phonemes but be able to have an almost limitless number of possible structures → combinatorially
What is a phoneme?
Smallest unit of perceived speech → sounds we make
Are there different phonemes in different languages, how /many are there per language. Give examples for each
Different phonemes in different languages
/l/ versus /r/ in English but not Japanese
Tonal differences, e.g. Chinese
Click sounds, e.g. Xhosa in South Africa
10 to 150 per language
~44 in English, ~11 in Rotokas (Papua New Guinea), ~109 West !Xoon (Botswana)
What do we call the language specific rules for combining phonemes?
phonology
What are morphemes
Smallest unit that signals meaning → can also be stand alone words too → any word can stand alone which is not true of any morphome
Combinations of phonemes
Prefixes, suffixes, roots, or entire words (the)
How many morphemes are there in languages?
Many thousands per language → can combine small amount of phonemes to make lots of morphemes
What do we call the language specific rules for combing morphemes
morphology
What are words?
Smallest stand-alone units of meaning
Combinations of one or more morphemes → morphemes can be a word
How many words are there per language?
Tens or hundreds of thousands per language
What do we call the language specific rules for combing words
syntax → order in which nouns and adjectives are combined is different for different languages
What are phrases
Organized grouping of one or more words
Play a particular role in grammatical structure of a sentence
How many phrases are there?
Almost limitless number
What do we call the specific rules for combining phrases (syntax)
E.g. “Joseph ate the apple.” in English (SVO)
E.g. “Yusif almani yedi.” in Azerbaijani (SOV) → more common ordering
What are sentences?
A set of words/phrases that (in principle) tells a complete thought
Can express a statement, question, exclamation, request, command, or suggestion
Sentences can be combined to form larger linguistic units (e.g. paragraphs)
How many sentences can there be?
most limitless number
Who came up with the theory about generatively of language?
Noam Chomsky
What did Noam Chomsky say about the generality of language?
We (including children) combine words in novel ways to express novel ideas
Thus language learning cannot be based solely on imitation, association, and reinforcement → can’t just say we copy language
We must learn a set of rules (grammar) that can be applied in a generative way
What did Noam Chomsky say that wasn’t quite true?
Language must be determined by an inborn biological program → may not be true
What is grammar?
Rules for language structure, including:
Morphology: Rules for combining morphemes into words
Syntax: Rules for combining words into phrases into sentences
What is semantics?
How meaning is derived from morphemes, words, phrases, and sentences
Explain this sentence using grammar/syntax and meaning/semantics:
Colorless green ideas sleep furiously
Grammatical but meaningless
Explain this sentence using grammar/syntax and meaning/semantics:
Furiously sleep ideas green colorless.
Ungrammatical and meningless
Explain this sentence using grammar/syntax and meaning/semantics:
Colorful green ants crawl furiously.
Grammatical and meaningful
Explain this sentence using grammar/syntax and meaning/semantics:
Colorful green ants crawls furiously.
Ungrammatical but meaningful
What happens in phrase structure?
Each word is assigned a role → happens implicitly in your brain
Generative grammar (chomsky): Rules specify what orders and combinations these roles can occur in
What is generative grammar and give examples?
Rules specify what orders and combinations these roles can occur in
Example rules:
S → NP VP
NP → (Article) N
VP → V NP
Noun phrase: the boy
Verb phrase: hit the ball
What is the problem with relying on phrase structure alone?
One phrase can have two meanings
Two phrase structures can have one meaning
How many phrase structures and meanings does this sentence have:
The shooting of the hunters was terrible.
1 phrase structure, 2 meanings
How many phrase structures and meanings does this sentence have:
The boy hit the ball
The ball was hit by the boy.
2 phrase structures, 1 meaning
Does phrase structure alone determine meaning?
No
What is surface structure:
Phrase structure that applies to order in which words are actually spoken
What is deep structure:
Fundamental, underlying phrase structure that conveys meaning → exists in your mind
What is transformational grammar?
Rules that transform among surface structures having same deep structure → how we know that two surface structures have the same deep structures (meaning)
Even Though the surface structure of two sentences may be quite different, a transformational grammar shows that the deep structure is the same
DO you get the deep or surface structure when you hear someone else speak
surface then you try to determine deep structure
What are these (surface or deep structures)?
The boy hit the ball
The boy hit the ball
2 surface structures
What is deep structure in this picture?
Deep structure is the same but the assertion/annotation is different
How many surface/ deep structures does this sentence have?
The shooting of the hunters was terrible.
1 surface structure and two deep structures
How many surface/ deep structures does this sentence have?
The boy hit the ball
The ball was hit by the boy.
Two surface structures, one deep structure:
What is ambiguity?
language with multiple interpretations
Multiple meanings that can be drawn from a single sequence of words
What does ambiguity provide insight into?
Like illusions for perception, ambiguity can provide insight into cognitive processing of language
Where is ambiguity often seen and what are some examples?
Newspaper headlines
Miners Refuse to Work After Death
Panda Mating Fails; Veterinarian Takes Over
Teacher Strikes Idle Kids
Enraged Cow Injures Farmer With Axe
Stolen Painting Found By Tree
What are the 3 types of ambiguity?
Lexical
Syntactic
Referential
What is lexical ambiguity?
When a word has two different meanings
What type of ambiguity are these:
He was bothered by the cold
Drunk gets nine months in violin case.
She noticed the port
Rose rose to put rose roes on her rows of roses.
Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo.
lexical
What is syntactic ambiguity?
When the same words can be grouped together into more than one phrase structure → meaning of each word is the same
What type of ambiguity is this?
They are cooking apples.
What type of ambiguity are these?
I saw the gorilla in my pajamas
Police help dog bite victim.
saw the man with the binoculars.
We saw her duck.
The chicken is ready to eat.
syntactic ambiguity
What is this an example of? (syntactic or lexical ambiguity)
She noticed the port.
Lexical but not syntactic ambiguity:
(1 phrase structure, 2 word meanings)
What is this an example of? (syntactic or lexical ambiguity)
I saw the man with the binoculars.
Syntactic but not lexical ambiguity:
(2 phrase structures, 1 word meaning)
What is this an example of? (syntactic or lexical ambiguity)
We saw her duck.
Syntactic and lexical ambiguity:
(2 phrase structures, 2 word meanings)
What is referential ambiguity?
When the same word/phrase can refer to two different things within a sentence.
The referring words (“it”, “she”, one …) are anaphors
What are anaphors and in what type of ambiguity are they seen?
The referring words (“it”, “she”, one …) are anaphors → refer to a person place or thing that have already been established
What type of ambiguity is this?
John grabbed his lunch, sat on a rock, and ate it.
referential
What type of ambiguity is this?
Susan told Elizabeth that she had to write a paper
referential
What type of ambiguity is this?
When a bright moon ends a dark day, a brighter one will follow.
referential
What type of ambiguity is this?
John loves his mother and Bill does too
Referential
What type of ambiguity is this?
The girl in the car that needed water is waiting.
Syntactic
What is speech production dependant on and what areas?
Fundamentally a motor act (moving muscles in mouth) dependent on hierarchical planning
Depends on prefrontal cortex areas (involved in planning of action
What area in the brain is involved in speech production specifically?
Broca’s area
In left hemisphere only (in most individuals)
What causes brooks aphasia
Due to damage to Broca’s area
What do patients with Broca’s aphasia show
Having struggle stringing words together → they know they are having struggles
Speech is labored, slow & nonfluent with awkward articulation
Phonemic errors, e.g. pelsil for pencil
Written output shows same errors as speech → language problem
Better fluency for memorized phrases
Singing may be more fluent than speech if learned before injury → is a highly practiced motor production
Comprehension is relatively spared
Problems with language planning and production (not a motor problem!)
What is aphasia
A language problem
What do broca’s aphasia patients show related to grammar?
Greatest difficulty with verbs, articles, pronouns (connecting words)
No verb inflection (conjugating verbs)
Responses make sense but are ungrammatical
Poor syntax comprehension → they can’t understand syntax.
If you say sally was hit by john → they won’t understand
Can only understand simple syntax
Poor at judging grammaticality
Difficulty reading and producing function words (a, and, for, she …)
Problems with understanding and using syntax ← modern view
What are the two main problems in patients with Broca’s aphasia?
Problems with understanding and using syntax
Problems with language planning and production (not a motor problem)
What is speech comprehension?
Fundamentally a perceptual process
Depends on the ventral “what” stream (in the back)
What area is specifically involved in speech comprehension?
Wernicke’s area (left hemisphere only)
What causes wernickes aphasia?
Due to damage to Wernicke’s area
What do wernikes aphasia patients show?
Speech is phonetically & grammatically normal but meaningless
Use made up words
Generally fluent, unlabored, well articulated
Normal intonation (prosody)
Words used inappropriately, nonsense words, “word salad”
Meaning expressed in roundabout way (circumlocution) → long time to get to that meaning
Comprehension is severely impaired → are not aware that their speech makes no sense
Effects all types of language → spoken and written
What are the three main issues with Wernikes aphasia?
Problems translating auditory input into phonological forms that can then access semantics
Problems with language comprehension
Problems with understanding and using semantics → meaning of language
How did researchers understand the difference in language networks between hemispheres?
Split brain studies
If a split brain patient is shown a picture of a dog in the left visual field, and a picture of a cat in the right visual field, and asked to draw what they see with their right hand, what would they draw?
A. A dog
B. A cat
C. A dog and a cat
D. Nothing
A cat
Cat goes into left V1 and a dog goes into right V1 → left brain understands the question and controls the right hand → Cat is drawn
What happens in split brain patients with visual info?
If object is presented in left visual field it ends up in right visual cortex
In a normal patient the info still goes over to left hemisphere
In a split brain person, info can’t get over to left hemisphere
What would happen to a split brain patient if they were given a pen in both hands
they might draw both at the same time
What is handedness
our tendency to use one side of the body over the other
What percentage of people are right handed, left handed, and cross-dominant/mixed handed?
Right-handed: 70–90%
Left-handed: ~10%
Cross-dominant/Mixed-handed: ~20%
What is language lateralization?
which side of the brain your language centers are on
What is the language lateralization of right-handed people?
95% left-hemisphere dominant, 5% right-hemisphere dominant
What is the language lateralization of left-handed people?
70% left-hemisphere dominant, 15% right-hemisphere dominant, 15% bilateral (language not on one specific side)
Are mots people left or right dominant for language?
left-side dominant for language
What is the right hemisphere involved in for language
Prosody:
What is prosody?
Not which words you say or the order of the words → how you say them
Intonation, tone, stress, and rhythm
Used for emotional state, form (statement, question, or command), irony or sarcasm, emphasis, contrast, and focus
What is aprosodia? and what are the 2 types?
Damage to certain parts of the brain
Productive or receptive aprosodia
What is productive aprosodia? and what area is it associated with?
Problem using prosody in your own language
Monotonic, “robotic” speech lacking emotional tone
Associated with damage to right hemisphere Broca’s equivalent
What is receptive aprosodia and what area is it associated with?
Difficulty understanding other people’s prosody
Difficulty detecting and understanding emotional tone in speech
Associated with damage to right hemisphere Wernicke’s equivalent
Where is language processed? according to interactive language network
Broca’s area (syntax & planning for production)
Right hemisphere equivalent of broca’s areas for productive prosody
Wernicke’s area (word perception & semantics)
Right hemisphere equivalent of Wernicke’s area for receptive prosody
Sensory cortices (e.g. auditory cortices for speech)
Motor cortices (e.g. motor cortex for speech) → for moving mouth or using sign language
Association cortices (semantics) → for comprehending and producing speech with meaning
Are there bottomm up and top down experiences to language? If so, give an example?
Yes
Actual word coming in → bottom up
Prior experience with language → top down
IS there recurrent and interactive processing in language?
yes
What does what we understand of language depend on?
Genes: Information learned on timescale of evolution
Past experience: Information learned on timescale of a human life
Internal state: Information learned on timescale of current episode
Environmental context: Information learned now
Proximal stimulus: The stimulus itself
What does the interactive activation theory show?
Effects of context & past experience
True for spoken language and understanding
Model of letter & word perception
Integrates bottom-up and top-down processes
–> At the same time that the letters are helping us perceive what the words are, the words help us to perceive the individual letters
What is the Mcgurk effect? and what does it show?
Misinterpretation due to conflicting stimuli
Shows interactivity of language → how your brain is combining lots of sources of information together
You are watching someone speak but the sound that you are hearing is different than the sound their lips are making → audio and visual are mismatched →
: If the audio is playing Ba and the video is of someone saying Ga → you hear Da → you hear something physically in between the sounds
What are garden path sentences and what does it show?
A sentence is parced online as we read
Shows us that we don’t wait to hear a whole sentence before we interpret it → rather our brain is attempting to interpret language word by word as it comes in → can lead our brain down a garden path → interpreting a sentence one way then you hit a word that no longer fits with the interpretation → then you have to reinterpret earlier parts of the sentence to make sense of the whole thing
What do these two garden path sentences show?
The ball thrown past the barn fell.
The ball rolled past the barn fell.
Same sentence structure but different past experiences leads us to interpret it differently
What do these garden path sentences show?
Fruit flies like a banana.
Time flies like an arrow.
Time flies like an arrow; fruit flies like a banana.
First half exerts contextual influence on second half → makes you want to perceive “flies” as the verb as well
How you interpret a sentence can be influenced by the grammatical structure of the surrounding sentences
What does the interactive language network explain?
Brocas and wernicke’s area are part of a larger interconnective area
Language network is highly recurrent, highly interactive and more than brocas and wernicke network
What is fMRI?
Functional Magnetic Resonance Imaging
fMRI looks at function and structure of the brain
What does fMRI measure?
Measures changes in magnetization of stuff in the brain, using electromagnetic radiation and nuclear magnetic resonance
How does fMRI work and how long does it take to see the blood flow?
Neural activity → Increased blood flow → Change in magnetic field → fMRI BOLD signal
When a part of brain is active, through neurovascular coupling, there is an increase in blood flow (haemodynamic response) → detect this using MRI machine
Increase in blood flow changes oxygenation of the blood → neurons take oxygen from the blood → dip in oxygen in that area → more blood is pumped there → oxygen level goes up → detects this because oxygenated hemoglobin and deoxygenated hemoglobin has different magnetic properties
BOLD signal → blood oxygenation level dependant signal
Measuring neural activity by measuring change in oxygenation level → takes a few seconds for brain to move blood to that area (5-6 seconds)
What are the characteristics of fMRI?
Very good spatial resolution (1-2 millimeters) → good at locating where
Ok temporal resolution (seconds)
Non-invasive
Low risk
Very high magnetic field (1 to 5 Tesla)
How is meaning represented in the brain?
By the relationship between concepts
How did Mitchell et al investigate the meaning in the brain?
- Find verbs that co-occur with nouns based on text analysis in lots of text
2.Bring people and get them to think of different verbs and determined brain activation for each verb using fMRI
- Predict activation for nouns as summation of activation for related verbs
- Test predictions… → brought people back in and had them think of different nouns and try to guess which nouns they are thinking of based of their brain activity
How many words of text did they use to investigate meaning in the brain?
trillions
What did they do for textual analysis when investigating meaning in the brain?
Search online text to find verbs near each noun
What did they do to identify brain areas whose activation is associated with different verbs when investigating meaning in the brain?
Brought people in and had them think about verbs such as eat, push and run.
For each one they recorded the brain activity using fMRI
Where do the words “eat”, “push” and “run” show activation in the brain?
Eat shows high activation is gustatory cortex that processes taste
When thinking about push there is a strong activation in the motor activity or somatosensory activation
Run activates superior temporal sulcus → associated with processing visual motion etc
Shows organization in representation
What did they do to predict activation for norms from verbs when investigating meaning in the brain?
Make a weighted sum of the brain activity for certain verbs and add it all together → becomes prediction of brain activity for celery
Since celery co occurs often with “eat” there is a strong weighting for brain activation associated with eating.
What did they do to test the predictions for nouns when investigating meaning in the brain?
Had their algorithm try to guess what word the person was thinking of without being told, just on which of the predicted patterns of brain activity was most similar to the actual pattern of brain activity
Showed that they could do that better than chance
