Osterhout (1997) B&L On the brain response to syntactic anomalies: Manipulations of word position and word class reveal individual differences

N400 Kutas & Hillyard (1980) Science Kutas & Hillyard (1984) Nature = 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

N400 Osterhout (1997) TICS Straightforward N400 effect for anomalous word P200 response to next word Next word presented (SOA = 650 msec)

P600 Osterhout & Holcomb (1992) JML Hagoort, Brown, & Groothusen (1993) LCP First published P600/(Syntactic Positive Shift) in response to ungrammatical words in sentences P200 response to next word Osterhout (1997) TICS Straightforward (& huge!) P600 effect for ungrammatical word Next word presented (SOA = 650 msec)

N400 + P600 Osterhout (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 effect pulls waveform more negative N400 & P600 have very similar scalp distributions

Osterhout (1997) B&L Experiment 1 - Stimuli Semantic Anomaly The cats won’t EAT the food that Mary leaves them. The cats won’t BAKE the food that Mary leaves them. Agreement Violations They 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 Semantic Anomaly Garden Path The boat sailed down the river and SANK (during the storm). Semantic Anomaly The boat sailed down the river and ATE (during the storm). Garden Path The 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&L Semantic Anomalies NOT typical N400 scalp distribution Too much frontal negativity Something else going on, too

Reflexive Agreement Violations But also Left Anterior Negativity (LAN)? P600 Pretty typical P600 scalp distribution

Garden-Path Sentences GP word sentence-medial GP sentences = Reduced Relatives N400 + P600 in response to GP word Previously, Osterhout got only P600 for these sentences

Garden-Path Sentences GP word sentence-final Similar N400+P600 pattern for GP word More late positivity overall because final word 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 Only Sentence-medial N = 12, Sentence-final N = 7 Comparing ERPs to the same word Only difference is 1 preceding word

“N400” Participants Only Sentence-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 across all 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