On the Neurocognitive Basis of Syntax Sydney Lamb l[email protected] 2010 November 12 Wenzao Ursuline College of Languages Kaohsiung, Taiwan
Jan 11, 2016
On the Neurocognitive Basis of Syntax
Sydney Lamb
2010 November 12
Wenzao Ursuline College of LanguagesKaohsiung, Taiwan
Why is it important to consider the brain?
“I gather…that the status of linguistic theories continues to be a difficult problem. … I would wish, cautiously, to make the suggestion, that perhaps a further touchstone may be added: to what esxtent does the throry tie in with other, non-linguistic information, for example, the anatomical aspects of language? In the end such bridges link a theory to the broader body of scientific knowledge.”
Norman Geschwind “The development of the brain and the evolution of language” Georgetown Round Table on Languages and Linguistics, 1964
The two big problems of neurosyntaxHow does the brain handle..
1. Sequencing – ordering of words in a sentence– And ordering of phonemes in a word
2. Categories– Noun, Verb, Preposition, etc.
• Subtypes of nouns, verbs, etc.– What categories are actually used in syntax?– How are syntactic categories defined?– How represented in the brain?– How does a child build up knowledge of such categories
based on just his/her ordinary language experience?
First step: accounting for sequence
• Important not just for language– Dancing– Eating a meal– Events of the day, of the year, etc.– Etc., etc.
• In language, not just syntax (lexotactics)– Ordering of morphemes in a word
• Morphotactics – Ordering of phonological elements in syllables
• Phonotactics – Ordering of sememes in a thought
Neurological Structures for Sequence
• How is sequencing implemented in neural structure?
• For an answer, consider the structure of the cortical column
Lasting activation in minicolumn
Subcorticallocations
Connections to neighboring columns not shown
Cell Types
Pyramidal
Spiny Stellate
Inhibitory
Recurrent axon branches keep activation alive in the column –Until is is turned off by inhibitory cell
Lasting activation in minicolumn
Subcorticallocations
Connections to neighboring columns not shown
Cell Types
Pyramidal
Spiny Stellate
Inhibitory
Recurrent axon branches keep activation alive in the column –Until is is turned off by inhibitory cell
Simple notation for lasting activation
Thick border for a node that stays active for a relatively long time Thin border for a node
that stays active for a relatively short time
N.B.: Nodes are implemented as cortical columns
Recognizing items in sequence
This link stays active
a b
Node c is satisfied by activation from both a and b If satisfied it sends activation to output connections Node a keeps itself active for a whileSuppose that node b is activated after node a Then c will recognize the sequence ab
c
This node recognizes the sequence ab
Example: eat apple(structure for recognition)
eat apple
eat apple
(Just labels, not part of the structure)
How does the delay element work?
• Remember: each node is implemented as a cortical column– Within the column are 75-110 neurons
• Enough for considerable internal structure• When node ab receives activation, it
– Sends activation on down to node a– And to the delay element, which
• Waits for activation from clock timer or feedback– Will come in on line labeled ‘f’ in diagram
• Upon receiving this signal, sends activation on to node b
Producing items in sequencea different means
a b
f
This would apply for items ‘a’ and ‘b’ in sequence where there is no ‘ab’ to be recognized as a unit.Example: Adjectives of size precede adjectives of color, which precede adjectives of material in the English noun phrase, as in big brown wooden box
Two different network notations
Narrow notation• Nodes represent cortical columns• Links represent neural fibers• Uni-directional• Close to neurological structure
Abstract notation• Nodes show type of relationship (OR,
AND)• Easier for representing linguistic
relationships• Bidirectional • Not as close to neurological structure
eat apple
eat apple
eat apple
eat apple
Two different network notationsNarrow notation
ab
a b
b
a b
Abstract notation Bidirectional
ab
a b f
Upward Downward
Constructions have meanings and functions
• They are also signs
Meaning/Function
Form/Expression
The sign relationship: a (neural) connection
The difference is that for a construction the expression is variable rather than fixed
The transitive verb phrase construction
CLAUSE DO-TO-SMTHG
Vt NP
Transitive verb phrase
Syntactic function
Semantic function
Variable expression
Add other types of predicate
CL
DO-TO-SMTHG
THING-DESCR
BE-SMTHG
be
NP
Vt
Adj
Vi
Loc
(A rough first approximation)
The other big problem for syntax
• Categories• Problems of categories are considered in a separate
presentation– “Categories in the Brain”
• Lexotactics uses very broad categories– We can say, e.g., “tried to eat a truck”
• For narrower categories, Semotactics– So the prototypical goals of EAT are edible objects