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

2. 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

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

4. 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)

5. 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

6. 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).

7. 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).

8. 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

9. Osterhout (1997) B&L Semantic Anomalies
NOT typical N400
scalp distribution
Too much frontal
negativity
Something else
going on, too

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

11. 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

12. Garden-Path Sentences GP word sentence-final
Similar N400+P600
pattern for GP word
More late positivity
overall because final
word in sentence

13. 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

14. “P600” Participants Only Sentence-medial N = 12, Sentence-final N = 7
Comparing ERPs to
the same word
Only difference is
1 preceding word

15. “N400” Participants Only Sentence-medial N = 2, Sentence-final N = 7
Comparing ERPs to
the same word
Only difference is
1 preceding word

16. GP N400 is like Sem Anom N400

17. Agree Viol P600 similar across all participants

18. 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