On the Neurocognitive Basis of Syntax Sydney Lamb l 2010 November 12 Wenzao Ursuline College of Languages Kaohsiung, 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 neurosyntax How 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 Subcortical locations 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

The ‘Wait’ Element W 1 2

Lasting activation in minicolumn Subcortical locations 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 while Suppose 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 (Just labels, not part of the structure)

Example: eat apple, eat banana (structure for recognition) eat apple eat banana eat apple banana

Producing items in sequence ab Wait element First a, then b

How does the delay element work? Remember: each node is implemented as a cortical column –Within the column are 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 sequence ab Delay element Carries feedback or clock signal f

Producing items in sequence ab May be within one cortical column f

Producing items in sequence a 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

Two different network notations Narrow notation ab b Abstract notation  Bidirectional ab 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

Linked constructions CL NP DO-TO-SMTHG Vt NP Transitive verb phrase The clause construction

Add a few more connections CL NP DO-TO-SMTHG Vt Transitive verb phrase ACTOR-DO

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