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LA NEUROSINTAXIS 2 13 ABR 2011 – DÍA 37. Neurolingüística del español SPAN 4270 Harry Howard Tulane University. ORGANIZACIÓN DEL CURSO. http://www.tulane.edu/~howard/SPAN4130-Neurospan/ El curso es apto para un electivo en neurociencia.
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LA NEUROSINTAXIS 213 ABR 2011 – DÍA 37 Neurolingüística del español SPAN 4270 Harry Howard Tulane University
ORGANIZACIÓN DEL CURSO • http://www.tulane.edu/~howard/SPAN4130-Neurospan/ • El curso es apto para un electivo en neurociencia. • Neurolinguistics and linguistic aphasiology está en reserva en la biblioteca. • Human Research Protection Program • http://tulane.edu/asvpr/irb/index.cfm • Before beginning research at Tulane University, all research personnel must complete the CITI Training Program; this can be completed at www.citiprogram.org. SPAN 4130 - Harry Howard - Tulane University
REPASO SPAN 4130 - Harry Howard - Tulane University
EEG • Electroencephalography (EEG) is the measurement of electrical activity produced by the brain as recorded from electrodes placed on the scalp. SPAN 4130 - Harry Howard - Tulane University
SCALP (CUERO CABELLUDO) EEG • Scalp EEG is collected from tens to hundreds of electrodes positioned on different locations at the surface of the head. • EEG signals (in the range of millivolts) are amplified and digitalized for later processing. SPAN 4130 - Harry Howard - Tulane University
ERP (POTENCIA EVOCADA) • Event-related brain potentials (ERPs) are positive and negative voltage fluctuations (or components) in the ongoing EEG that are time-locked to the onset of a sensory, motor, or cognitive event. • ERPs reflect brain activity that is specifically related to some stimulus or other event. • This activity cannot be directly observed in the EEG • the EEG is a composite of simultaneously occurring brain activity • it doesn't reflect just the activity associated with the event of interest • In other words, the "signal" (the brain response to some event) is swamped by the "noise" (the brain activity that is unrelated to that event). SPAN 4130 - Harry Howard - Tulane University
SIGNAL AVERAGING • The solution to this problem is to present not just one instance of the event of interest, but many instances. • Epochs of brain activity, each one time-locked to the onset of an event, are then averaged together. • The "random" activity washes out during averaging, whereas the brain activity of interest - namely, what is constant over presentations of the event of interest - stays in the signal. • Through this signal-averaging procedure, it is possible to isolate the brain response that is specifically elicited in response to some event of interest. SPAN 4130 - Harry Howard - Tulane University
ERP PROCEDURE SPAN 4130 - Harry Howard - Tulane University
ERP COMPONENTSNAMED BY THEIR POLARITY AND PEAK LATENCY (IN MS) SPAN 4130 - Harry Howard - Tulane University
NEUROCOGNITIVE MODEL OF AUDITORY SENTENCE PROCESSING SPAN 4130 - Harry Howard - Tulane University
Brodmann areas in the left hemisphere Inferior frontal gyrus (IFG) = green, Superior temporal gyrus (STG) = red Middle temporal gyrus (MTG) = blue SPAN 4130 - Harry Howard - Tulane University
INTRODUCTION • The first phase (100-300 ms) represents the time window in which the initial syntactic structure is formed on the basis of information about word category. • For instance, the insertion of a contracted preposition+article between an auxiliary verb and past participle in German, produces a significantly higher ERP amplitude during this period than the same sentence without the intrusive material • Die Gans wurde (*im) gefüttert. • The goose was (*in the) fed. SPAN 4130 - Harry Howard - Tulane University
PHRASES CAN BE PUT TOGETHER TO FORM SENTENCES • Striped orange cats slept soundly. • Colorless green ideas slept furiously. SPAN 4130 - Harry Howard - Tulane University
The ELAN SPAN 4130 - Harry Howard - Tulane University Early left anterior negativity
SINCE THE MEANING DOESN’T MATTER, WE CAN WRITE WORD-ORDER RULES BASED ON CATEGORIES • A noun phrase (NP) consists of … ? • An optional determiner followed by one or more adjectives followed by a noun • NP (Det) Adj (Adj) N • A verb phrase (VP) consists of … ? • A verb followed by an adverb • VP V Adv • A sentence consists of … ? • A noun phrase followed by a verb phrase • S NP VP SPAN 4130 - Harry Howard - Tulane University
BUT SUCH A REAL GRAMMAR IS FAIRLY COMPLEX • Perhaps too complex for direct study • They can teach subjects a simplified set of rules from a language that they do not know. • But even better is to teach subjects an artificial grammar (the syntactic analog of a nonsense word) which have easy-to-control properties. SPAN 4130 - Harry Howard - Tulane University
A REGULAR GRAMMAR • The rules • S Xab • X Xab • X ab • How would you generate the string “ababab”? • This language is known as (ab)n. • From fMRI we know that violations of this grammar activate BA 44 and BA 6. • The English grammar that we made up is also of this type. • So are the violations of German grammar. SPAN 4130 - Harry Howard - Tulane University
A CONTEXT-FREE GRAMMAR • The rules • S aXb • X aXb • X ab • How would you generate the string “aaabbb”? • How would you generate the string “ababab”? • This language is known as anbn. • From fMRI we know that violations of this grammar activate BA 44, but not BA 6. SPAN 4130 - Harry Howard - Tulane University
The LAN SPAN 4130 - Harry Howard - Tulane University Left anterior negativity Phase 2 (300-500 ms)
OVERVIEW • The LAN component is observed with: • morphosyntactic errors • filler-gap dependencies SPAN 4130 - Harry Howard - Tulane University
SUBCATEGORIZATION VIOLATIONSIN GERMAN 1 (RÖSLER ET AL. 1993) • The passive voice only applies to transitive verbs: • Someone greeted the president. > • The president was greeted. • The teacher fell. > • *The teacher was fallen. • We say that (4) violates the subcategorization requirement of fall, which is that it cannot take a direct object • Sample test sentences in German • Der Präsident wurde begrüßt. • the president is-being greeted • *Der Lehrer wurde gefallen. • the teacher is-being fallen SPAN 4130 - Harry Howard - Tulane University
SUBCATEGORIZATION VIOLATIONSIN GERMAN 2 (RÖSLER ET AL. 1993) • In German, verbs take one auxiliary (haben) or another (sein) in the perfect tenses: • Der Clown hat gelacht. • the clown has laughed • Der Dichter ist gegangen. • the poet has left • Sample test sentences: • Der Clown hat gelacht. • *Der Dichter hat gegangen. SPAN 4130 - Harry Howard - Tulane University
AGREEMENT VIOLATIONS IN ENGLISH (OSTERHOUT & MOBLEY 1995) • Verbs must agree with their subjects in number • The elected officials {hope/*hopes} to succeed. • Reflexive pronouns must agree with their antecedents in number and gender • Number: The hungry guests helped {themselves/*himself} to food. • Gender: The successful woman congratulated {herself/*himself} on the promotion. SPAN 4130 - Harry Howard - Tulane University
ALSO … • with English pronouns marked incorrectly for case, Coulson et al. (1998), • with German nouns not agreeing with their articles, Gunter et al. (2000), • with Spanish nouns not agreeing with their articles, Barber & Carreiras (2005) • etc. SPAN 4130 - Harry Howard - Tulane University
EL PRÓXIMO DÍA SPAN 4130 - Harry Howard - Tulane University Más neurosintaxis