Osterhout (1997) B&L

On the brain response to syntactic anomalies: Manipulations of word

position and word class reveal individual differences

N400Kutas & Hillyard (1980) Science= First published N400 in response to semantically anomalous words in sentences

Kutas & Hillyard (1984) Nature= First published demonstration that N400 amplitude reflects degree of semantic anomaly

Osterhout (1997) TICS- Straightforward N400 effect for anomalous word

P200 response to next word

Next word presented (SOA = 650 msec)

N400

P600

P200 response to next word

Next word presented (SOA = 650 msec)

Osterhout & Holcomb (1992) JMLHagoort, Brown, & Groothusen(1993) LCP- First published P600/(Syntactic Positive Shift) in response to ungrammatical words in sentences

Osterhout (1997) TICS- Straightforward (& huge!) P600 effect for ungrammatical word

N400 + P600Osterhout (1997) TICS- Both components evoked by same word that has both semantic & grammatical problems in the context- Unusually clean!

P600 amplitude a bit lower, probably because continuing N400 effectpulls waveform more negative- N400 & P600 have very similar scalp distributions

Osterhout (1997) B&L

Experiment 1 - Stimuli

Semantic AnomalyThe cats won’t EAT the food that Mary leaves them.

The cats won’t BAKE the food that Mary leaves them.

Agreement ViolationsThey said you were wandering about and talking to YOURSELF (in Latin).

They said you were wandering about and talking to MYSELF (in Latin).

Stimulus Sentences

Experiment 2 - Stimuli

The boat sailed down the river and SANK (during the storm).

Semantic AnomalyThe boat sailed down the river and ATE (during the storm).

Garden PathThe boat floated down the river SANK (during the storm).

Procedures/Design• Sentences presented word-by-word centrally • SOA = 650 msec (slow!)• End-of-sentence acceptability judgments

• Expt 1 – N = 16– 120 sets of 4 sentence versions in Agree Viol conds (30)– 60 sets of 2 sentence versions in Sem Anom conds (30)– So, 90 unacceptable + 90 acceptable sentences = 180 trials– No distractors

• Expt 2– N = 30– 90 sets of 3 sentence versions in Sem Anom/GP conds (30)

– Sentence length = between subjects manipulation

– 60 sets of 2 sentence versions in Agree Viol conds (30)– 30 distractors (15 unacceptable)– So, 75 unacceptable + 75 acceptable + 30 ? = 180 trials

Osterhout (1997) B&LSemantic Anomalies

N400

NOT typical N400scalp distribution- Too much frontal negativity- Something else going on, too

Reflexive Agreement Violations

Pretty typical P600scalp distribution

P600

But also Left Anterior Negativity (LAN)?

Garden-Path SentencesGP word sentence-medial

GP sentences= Reduced Relatives

N400 + P600in response toGP word- Previously, Osterhout got only P600 for these sentences

Garden-Path SentencesGP word sentence-final

Similar N400+P600pattern for GP word

More late positivityoverall because finalword in sentence

Individual Differences

• Grand means showed N400 followed by P600– BUT, when looked at individual participant

means, discovered that they showed either N400 or P600, but no one showed both

• So grand means are quite misleading!

• Unrelated to only individual difference measures collected– Gender– Handedness

“P600” Participants OnlySentence-medial N = 12, Sentence-final N = 7

Comparing ERPs to the same word- Only difference is 1 preceding word

“N400” Participants OnlySentence-medial N = 2, Sentence-final N = 7

Comparing ERPs to the same word- Only difference is 1 preceding word

GP N400 is like Sem Anom N400

Agree Viol P600 similar acrossall participants

• Osterhout (personal communication) has recently found that doing frequency decomposition of the EEG at the critical point in the good versions of the sentences & looking at the power in different frequency bands predicts whether a participant will show N400 or P600 in the GP sentences