Are the anterior negativities to grammatical violations indexing working memory? Manuel Martin-Loeches, Francisco munoz, Pilar Casado, A. Melcon, C. Fernandez-frias, Psychophysiology 42, 2005, Presented by Dora Lu, 09/13/2006
ERP Component: N400 Kutas & Hillyard. (1980).
ERP Component: P600 Osterhout & Nicol (1999)
Anterior Negativities Neville et al (1991): Semantic anomaly: The scientist criticized Max’s event of the theorem. Phrase structure violation: The scientist criticized Max’s of proof the theorem. Specificity constraint violation: What did the scientist criticize Max’s proof of? Subjacency Constraint violation: What was a proof of criticized by the scientist?
Neville et al (1991) N400 N125 P500
Neville et al (1991): difference wave
(early) (left) Anterior Negativities A negative component that peaks between ms after stimulus onset, usually with anterior distribution, sometimes lateralized (e.g. Neville et al 1991)
When will (early) (left) Anterior Negativities appear? Grammatical violations Word category violations (disrupt the building of the phrase structure) – early left anterior negativity (e.g. Friederici et al 1996) Syntactic-category violation: The metal was refined by the goldsmith who was honored. The metal was for refined by the goldsmith who was honored. Syntactic-category ambiguity: The metal was for refining melted by the goldsmith who was honored. The metal was/became refining melted by the goldsmith who was honored. Morphosyntactic violations (gender/number agreement, verb inflection violations) – anterior negativity (e.g. Vos et al. 2001) The tourist have a busy schedule and visit the theater that very famous is. The tourist have a busy schedule and visits the theater that very famous is. The tourist that a busy schedule have, visit the theater that very famous is. The tourist that a busy schedule have, visits the theater that very famous is. Working memory demand (Kluender & Kutas 1993)
What these anterior negativities represent for? Reflect automatic first-pass parsing process, such as detecting morphosyntactic mismatch, inability to build the phrase structure (e.g. Hagoort 2003) Reflecting working memory operation or working memory load. AN have been found in grammatically well-formed sentences that demand large amount of working memory resources. (e.g. Kluender & Kutas 1993) The amplitude of LAN to morphosyntactic violations was affected by the working memory span of the subjects. (e.g. Vos et al 2001)
Unsettled issues about AN: When will you see AN? Grammatical violations: morphosyntactic and word category violations Do these two grammatical violations reflect the same process? (Friederici 2002: word category >> morphosyntactic process, but Hagoort 2003: artifacts of the moment when the violation appears) Different distribution of AN: because of different grammatical violations are used Whether it is related to working memory operations? Controversial – some studies failed to elicit it, effects are small, distribution is not consistent
Current Study Directly compare responses caused by working memory with those caused by grammatical manipulations. Two grammatical violations: word category & morphosyntactic violations Working memory load: relative clauses vs short, SR vs OR (structural difficulties)
Experimental stimuli Short sentence: (The composer edited the opera.) Correct: El compositor edito la opera. Category violation: El compositor edicion la opera. Morphosyntactic violation: El compositor edite la opera. Center embedded subject relative clause: (The composer [that hated the singer] edited the opera.) El compositor [que odio al cantante] edito la opera. El compositor [que odio al cantante] edicion la opera. El compositor [que odio al cantante] edite la opera. Center embedded object relative clause: (The composer [that the singer hated] edited the opera.) El compositor [que el cantante odio] edito la opera. El compositor [que el cantante odio] edicion la opera. El compositor [que el cantante odio] edite la opera.
Methods Participants: 32 Spanish speakers Stimuli: 180 sets (60 simple sentences, 60 SR, 60 OR) fillers (40 ungrammatical sentences with different violations) Word-by word center presentation, 300ms duration, 500ms SOA, 1500ms between each sentence Participants perform grammaticality judgment Recordings: 29 electrodes
Behavioral results Grammaticality judgment: People did pretty good for the grammaticality judgments. 93.2% for grammatical and 97.3% for ungrammatical sentences. People did worse for correct sentences with an object-relative clause (86.4%). Reaction time: People spent 100ms more to respond to correct OR clauses. (683ms for short, 792ms for OR, 618 for SR)
ERP results: Relative Clause region S: The composer edited the opera. SR: The composer [that hated the singer] edited the opera. OR: The composer [that the singer hated] edited the opera. Onset of 1 st word 1000ms, 3 rd word AN: both SR & OR
ERP results: Relative Clause region S: The composer edited the opera. SR: The composer [that hated the singer] edited the opera. OR: The composer [that the singer hated] edited the opera. Frontal distribution, slightly lateralized
ERP results: Relative Clause region SR: The composer [that hated the singer] edited the opera. OR: The composer [that the singer hated] edited the opera. 4 th word, 1500ms after sentence onset, OR has increasing AN, and more centrally distributed
ERP results: Main verb region (short) S: El compositor edito la opera. WV: El compositor edicion la opera. MV: El compositor edite la opera. AN P600 More bilateral
ERP results: Main verb region (SR) C: El compositor [que odio al cantante] edito la opera. WV: El compositor [que odio al cantante] edicion la opera. MV: El compositor [que odio al cantante] edite la opera. Only WC has posterior negativity! P600 larger for MV
ERP results: Main verb region (OR) C: El compositor [que el cantante odio] edito la opera. WV: El compositor [que el cantante odio] edicion la opera. MV: El compositor [que el cantante odio] edite la opera. No AN P600
ERP results: Main verb of relative clause S: The composer edited the opera. SR: The composer [that hated the singer] edited the opera. OR: The composer [that the singer hated] edited the opera. SR vs short: Long duration effect, wide frontal or frontal- central start about 200ms SR vs OR: long duration effect has parietal distribution
Comparing working memory related and syntactical related negativities 4 frontal negativities related to working memory 2 frontal negativities related to grammatical violations Frontal negativities related to grammatical violations has narrower distribution (Fig. 2)
Discussion Frontal negativities related to grammatical violation and working memory are qualitatively different in terms of topography and duration. Left lateralization is more reliable for grammatical related negativities Negativities related to working memory has wider distribution, involving most of the anterior part Duration could be one criterion to dissociate the two types of negativities. Working memory related negativities display longer duration. The syntactic operations involved in grammatical violation and working memory may not be independent. When working memory resources are demanded, the AN that reflects grammatical violations is reduced. two types negativities are different but might from the same resource.
Discussion Two types of grammatical violations do not differ significantly. No latency difference. Found parietal negativities in SR word category violation. probably because local structural differences. There is an ambiguity about whether the wrong noun should be an adjective or a verb. C: El compositor [que odio al cantante] edito la opera. WV: El compositor [que odio al cantante] edicion la opera Coulson et al (1998) Pronoun Case: The plane took *we to paradise and back. The plane took us to paradise and back. Verb agreement: Every Monday he *mow the lawn. Every Monday he mows the lawn.
Discussion Why bilateral parietal long duration negativities rather than AN in SR and OR’s main verb region? could be grammatical and themantic role assignment in OR The P600 is larger in morphosyntactic violation than word category violation. Morphosyntactic violations induce reanalysis and repair operation.
So, are you convinced? Negativities reflect at least two different cognitive processes. Although processes are different, they might use the same resources. But…will different types of grammatical violations yield the same results? Different degrees of grammatical violations. For example, verb/noun violation vs noun/preposition violations. Can we generalize that AN functions as a grammatical mismatch detector? Or just a detector for processing difficulties? Or could it reflect attention shift?