Download presentation
Presentation is loading. Please wait.
1
Abstract Neuron { o u t p u t y i n p u t i i2 in i1 . . . w0 i0=1 w2
1 if net > 0 0 otherwise { w0 i0=1 w2 wn w1
2
Link to Vision: The Necker Cube
4
Constrained Best Fit in Nature
inanimate animate physics lowest energy state chemistry molecular minima biology fitness, MEU Neuroeconomics vision threats, friends language errors, NTL
5
Computing other relations
The 2/3 node is a useful function that activates its outputs (3) if any (2) of its 3 inputs are active Such a node is also called a triangle node and will be useful for lots of representations.
6
Triangle Nodes: Encoding relational information with abstract neurons
The triangle node (aka 2/3 node) is a useful function that activates its outputs (3) if any (2) of its 3 inputs are active Such a node will be useful for lots of representations.
7
Triangle nodes and McCullough-Pitts Neurons
Relation (A) Object (B) Value (C) A B C
8
Basic Ideas Parallel activation streams.
Top down and bottom up activation combine to determine the best matching structure. Triangle nodes bind features of objects to values Mutual inhibition and competition between structures Mental connections are active neural connections
9
5 levels of Neural Theory of Language
Pyscholinguistic experiments Spatial Relation Motor Control Metaphor Grammar Cognition and Language Computation Structured Connectionism abstraction Neural Net SHRUTI Computational Neurobiology Triangle Nodes Biology Neural Development Quiz Midterm Finals
10
Behavioral Experiments
Identity – Mental activity is Structured Neural Activity Spreading Activation — Psychological model/theory behind priming and interference experiments Simulation — Necessary for meaningfulness and contextual inference Parameters — Govern simulation, strict inference, link to language
11
Bottom-up vs. Top-down Processes
Bottom-up: When processing is driven by the stimulus Top-down: When knowledge and context are used to assist and drive processing Interaction: The stimulus is the basis of processing but almost immediately top-down processes are initiated
12
Stroop Effect Interference between form and meaning
13
Name the words Book Car Table Box Trash Man Bed
Corn Sit Paper Coin Glass House Jar Key Rug Cat Doll Letter Baby Tomato Check Phone Soda Dish Lamp Woman
14
Name the print color of the words
Blue Green Red Yellow Orange Black Red Purple Green Red Blue Yellow Black Red Green White Blue Yellow Red Black Blue White Red Yellow Green Black Purple
15
Body-Specificity Hypothesis
If concepts and word meanings are constituted, in part, by mental simulations our own perceptions and actions… …then their neurocognitive representations should differ for people with different kinds of bodies, who perceive and act upon the environment in systematically different ways. (Casasanto, in review, link on course page)
16
Testing body-specificity
pinch chew In between the red and blue boxes is a white box filled with hundreds of clear glass marbles. Ss would see one word at a time in the center of the screen, in red or blue font, and move one marble into the box that matched the color of the font. Manual Action Non-Manual Action
17
Testing body-specificity
For one block of trials they’d use only their left hand, and the other block only their right hand -- block order was counterbalaced across Ss. Left handed movements for one block of trials Right handed movements for the other block of trials
18
Design 96 Words (48 manual verbs, 48 non-manual verbs)
2 blocks (LH movements, RH movements) 2 groups of Ss (Left handers, Right handers) Dependent measures: RT & Surprise recognition (Old/New) So, here’s the full design: There were 96 words, all of which were action verbs -- unbeknownst to the subject, half of them named Manual actions that we normally perform with one hand -- our dominant hand -- and the other half named Non-Manual actions.
19
Move marbles by word color
caress jab fling grip pound tap yank erase dial sigh cough growl watch crawl peek tumble dance say Importantly, the only instruction was to move marbles according to the color of the word -- word meaning was completely irrelevant to the task. But we expected people would read the word they saw in front of them, and would automatically activate they meaning, whether they wanted to or not, and we make the following predictions about what that meaning is made of: Manual Action Non-Manual Action
20
Predictions If action word meanings are constituted, in part, by mental simulation of perceptuo-motor experiences, then: Both online and offline effects of congruity should be found between manual motor actions and the meanings of manual action verbs (but not non-manual action verbs). Right and left handed participants should show opposite effects of using their right and left hands to move marbles during incidental encoding of manual action verbs. (Casasanto, in review)
21
Non-Manual Action Verb
Reaction Time Results Non-Manual Action Verb ns *** *** Marble movement time in ms Here’s what we found: Manual Action Verb (Casasanto, in review)
22
Handedness-ness predicts congruity effect
ABS Laterality Quotient Congruity effect in ms Furthermore, We gave Ss the Edinburgh handedness inventory…
23
Recognition Memory Results
ns Non-Manual Action Verb 0.80 LeftHand RightHand 0.75 *** *** 0.70 Proportion correct recognition 0.65 0.60 0.55 0.50 LEFTIES RIGHTIES Manual Action Verb (Casasanto, in review)
24
Procedure for experiment that demonstrates the word-superiority effect
Procedure for experiment that demonstrates the word-superiority effect. First the word is presented, then the mask XXXX’s, then the letters.
25
Word-Superiority Effect Reicher (1969)
Which condition resulted in faster & more accurate recognition of the letter? The word condition Letters are recognized faster when they are part of a word then when they are alone This rejects the completely bottom-up feature model Also a challenge for serial processing
26
Connectionist Model McClelland & Rumelhart (1981)
Knowledge is distributed and processing occurs in parallel, with both bottom-up and top-down influences This model can explain the Word-Superiority Effect because it can account for context effects
27
Connectionist Model of Word Recognition
28
Basic Ideas Parallel activation streams.
Top down and bottom up activation combine to determine the best matching structure. Triangle nodes bind features of objects to values Mutual inhibition and competition between structures Mental connections are active neural connections
29
Interaction in language processing: Pragmatic constraints on lexical access
Jim Magnuson Columbia University
30
Information integration
A central issue in psycholinguistics and cognitive science: When/how are such sources integrated? Two views Interaction Use information as soon as it is available Free flow between levels of representation Modularity Protect and optimize levels by encapsulation Staged serial processing Reanalyze / appeal to top-down information only when needed
32
Reaction Times in Milliseconds after: “They all rose”
0 delay ms. delay flower 685 659 stood 677 623 desk 711 652
33
Example: Modularity and word recognition
Tanenhaus et al. (1979) [also Swinney, 1979] Given a homophone like rose, and a context biased towards one sense, when is context integrated? Spoken sentence primes ending in homophones: They all rose vs. They bought a rose Secondary task: name a displayed orthographic word Probe at offset of ambiguous word: priming for both “stood” and “flower” 200 ms later: only priming for appropriate sense Suggests encapsulation followed by rapid integration But the constraint here is weak -- overestimates modularity? How could we examine strong constraints in natural contexts?
35
“They all rose” triangle nodes:
when two of the abstract neurons fire, the third also fires model of spreading activation
36
Allopenna, Magnuson & Tanenhaus (1998)
Eye Eye camera tracking computer Scene camera ‘Pick up the beaker’
37
Do rhymes compete? Cohort (Marlsen-Wilson): onset similarity is primary because of the incremental nature of speech (serial/staged; Shortlist/Merge) Cat activates cap, cast, cattle, camera, etc. Rhymes won’t compete NAM (Neighborhood Activation Model; Luce): global similarity is primary Cat activates bat, rat, cot, cast, etc. Rhymes among set of strong competitors TRACE (McClelland & Elman): global similarity constrained by incremental nature of speech Cohorts and rhymes compete, but with different time course TRACE predictions
38
Allopenna et al. Results
39
Study 1 Conclusions Time locked to speech at a fine grain
As predicted by interactive models, cohorts and rhymes are activated, with different time courses Eye movement paradigm More sensitive than conventional paradigms More naturalistic Simultaneous measures of multiple items Transparently linkable to computational model Time locked to speech at a fine grain
40
Theoretical conclusions
Natural contexts provide strong constraints that are used When those constraints are extremely predictive, they are integrated as quickly as we can measure Suggests rapid, continuous interaction among Linguistic levels Nonlinguistic context Even for processes assumed to be low-level and automatic Constrains processing theories, also has implications for, e.g., learnability
41
Producing words from pictures or from other words: A comparison of aphasic lexical access from two different input modalities Gary Dell with Myrna Schwartz, Dan Foygel, Nadine Martin, Eleanor Saffran, Deborah Gagnon, Rick Hanley, Janice Kay, Susanne Gahl, Rachel Baron, Stefanie Abel, Walter Huber
42
Boxes and arrows in the linguistic system
Semantics Syntax Lexicon Output Phonology Input Phonology
43
Picture Naming Task Semantics Say: “cat” Syntax Lexicon Output Phonology Input Phonology
44
A 2-step Interactive Model of Lexical Access in Production
Semantic Features FOG DOG CAT RAT MAT f r d k m ae o t g Onsets Vowels Codas
45
Step 1 – Lemma Access Activate semantic features of CAT FOG DOG CAT
RAT MAT f r d k m ae o t g Onsets Vowels Codas
46
Step 1 – Lemma Access Activation spreads through network FOG DOG CAT
RAT MAT f r d k m ae o t g Onsets Vowels Codas
47
Step 1 – Lemma Access Most active word from proper category is selected and linked to syntactic frame NP N FOG DOG CAT RAT MAT f r d k m ae o t g Onsets Vowels Codas
48
Step 2 – Phonological Access
Jolt of activation is sent to selected word NP N FOG DOG CAT RAT MAT f r d k m ae o t g Onsets Vowels Codas
49
Step 2 – Phonological Access
Activation spreads through network NP N FOG DOG CAT RAT MAT f r d k m ae o t g Onsets Vowels Codas
50
Step 2 – Phonological Access
Most activated phonemes are selected FOG DOG CAT RAT MAT Syl On Vo Co f r d k m ae o t g Onsets Vowels Codas
51
Semantic Error – “dog” NP N
Shared features activate semantic neighbors NP N FOG DOG CAT RAT MAT f r d k m ae o t g Onsets Vowels Codas
52
Formal Error – “mat” NP N
Phoneme-word feedback activates formal neighbors NP N FOG DOG CAT RAT MAT f r d k m ae o t g Onsets Vowels Codas
53
Mixed Error – “rat” Mixed semantic-formal neighbors gain activation from both top-down and bottom-up sources NP N FOG DOG CAT RAT MAT f r d k m ae o t g Onsets Vowels Codas
54
Errors of Phonological Access- “dat” “mat”
Selection of incorrect phonemes FOG DOG CAT RAT MAT Syl On Vo Co f r d k m ae o t g Onsets Vowels Codas
55
A Test of the Model: Picture-naming Errors in Aphasia
“cat” 175 pictures of concrete nouns–Philadelphia Naming Test 94 patients (Broca,Wernicke, anomic, conduction) 60 normal controls
56
Response Categories Correct Semantic Formal Mixed Unrelated Nonword
CAT DOG MAT RAT LOG DAT Continuity Thesis: Normal Error Pattern: 97% Correct Random Error Pattern: 80% Nonwords cat dog mat rat log dat cat dog mat rat log dat
57
Implementing the Continuity Thesis
2. Set processing parameters of the model so that its error pattern matches the normal controls. Random Pattern Model Random Pattern cat dog mat rat log dat Normal Controls Model Normal Pattern 1.Set up the model lexicon so that when noise is very large, it creates an error pattern similar to the random pattern. cat dog mat rat log dat
58
Lesioning the model: The semantic-phonological weight hypothesis
Semantic Features Semantic-word weight: S FOG DOG CAT RAT MAT Phonological- word weight: P f r d k m ae o t g Onsets Vowels Codas
59
Patient CAT DOG MAT RAT LOG DAT
Correct Semantic Formal Mixed Unrelated Nonword LH s=.024 p= IG s=.019 p= GL s=.010 p=
60
Representing Model-Patient Deviations
Root Mean Square Deviation (RMSD) LH .016 IG GL .043
61
94 new patients—no exclusions
94.5 % of variance accounted for
62
Conclusions The logic underlying box-and-arrow- models
is perfectly compatible with connectionist models. Connectionist principles augment the boxes and arrows with -- a mechanism for quantifying degree of damage -- mechanisms for error types and hence an explanation of the error patterns Implications for recovery and rehabilitation
63
Behavioral and Imaging Experiments Ben Bergen and Shweta Narayan
Do Words and Images Match? Behavioral – Image First Does shared effector slow negative response? Imaging – Simple sentence using verb first Does verb evoke activity in motor effector area?
64
Structured Neural Computation in NTL
The theory we are outlining uses the computational modeling mechanisms of the Neural Theory of Language (NTL). NTL makes use of structured connectionism (Not PDP connectionism!). NTL is ‘localist,’ with functional clusters as units. Localism allows NTL to characterize precise computations, as needed in actions and in inferences.
65
Simulation To understand the meaning of the concept grasp, one must at least be able to imagine oneself or someone else grasping an object. Imagination is mental simulation, carried out by the same functional clusters used in acting and perceiving. The conceptualization of grasping via simulation therefore requires the use of the same functional clusters used in the action and perception of grasping.
66
Parameters All actions, perceptions, and simulations make use of parameters and their values. Such neural parameterization is pervasive. E.g., the action of reaching for an object makes use of the parameter of direction; the action of grasping an object makes use of the parameter of force. The same parameter values that characterize the internal structure of actions and simulations of actions also characterize the internal structure of action concepts.
67
Advantages of Structured Connectionism
Structured connectionism operates on structures of the sort found in real brains. From the structured connectionism perspective, the inferential structure of concepts is a consequence of the network structure of the brain and its organization in terms of functional clusters.
68
Multi-Modal Integration
Cortical premotor areas are endowed with sensory properties. They contain neurons that respond to visual, somatosensory, and auditory stimuli. Posterior parietal areas, traditionally considered to process and associate purely sensory information, alsos play a major role in motor control.
69
Somatotopy of Action Observation
Foot Action Hand Action Mirror Neurons: Parietal, Premotor (Area ), and Broca’s (45) A: mimicked actions; no parietal activation B: Action on objects; Parietal activation. Point: location determined by action. Mouth Action Buccino et al. Eur J Neurosci 2001
70
The Simulation Hypothesis
How do mirror neurons work? By simulation. When the subject observes another individual doing an action, the subject is simulating the same action. Since action and simulation use some of the same neural substrate, that would explain why the same neurons are firing during action-observation as during action-execution.
71
Mirror Neurons Achieve
Partial Universality, since they code an action regardless of agent, patient, modality (action/observation/hearing), manner, location. Partial Role Structure, since they code an agent role and a purpose role. The Agent Role: In acting, the Subject is an agent of that action. In observing, the Subject identifies the agent of the action as having the same role as he has when he is acting – namely, the agent role. The Purpose Role: Mirror neurons fire only for purposeful actions.
72
The Sensory-Motor System Is Sufficient
Conclusion 1 The Sensory-Motor System Is Sufficient For at least one concept, grasp, functional clusters, as characterized in the sensory-motor system and as modeled using structured connectionist binding and inference mechanisms, have all the necessary conceptual properties.
73
The Neural Version of Ockham’s Razor
Conclusion 2 The Neural Version of Ockham’s Razor Under the traditional theory, action concepts have to be disembodied, that is, to be characterized neurally entirely outside the sensory motor system. If true, that would duplicate all the apparatus for characterizing conceptual properties that we have discussed. Unnecessary duplication of this sort is highly unlikely in a brain that works by neural optimization.
74
Behavioral Experiments Ben Bergen and Shweta Narayan
Do Words and Images Match? Does shared effector slow negative response? Behavioral – Image First Does verb evoke activity in motor effector area?
76
WALK
78
GRASP
80
WALK
81
Preliminary Behavior Results
Same Action Other Effector Same Effector 788 804 871 767 785 825 40 Native Speakers Eliminate RT > 2 sec.
82
5 levels of Neural Theory of Language
Spatial Relation Motor Control Metaphor Grammar Cognition and Language Computation Structured Connectionism abstraction Neural Net SHRUTI Computational Neurobiology Triangle Nodes Biology Neural Development Quiz Midterm Finals
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.