N400 or N-400 may refer to:
The N400 is a component of time-locked EEG signals known as event-related potentials (ERP). It is a negative-going deflection that peaks around 400 milliseconds post-stimulus onset, although it can extend from 250-500 ms, and is typically maximal over centro-parietal electrode sites. The N400 is part of the normal brain response to words and other meaningful (or potentially meaningful) stimuli, including visual and auditory words, sign language signs, pictures, faces, environmental sounds, and smells.
The N400 was first discovered by Marta Kutas and Steven Hillyard in 1980. They conducted the first experiment looking at the response to unexpected words in read sentences, expecting to elicit a P300 component. The P300 had previously been shown to be elicited by unexpected stimuli. Kutas and Hillyard therefore used sentences with anomalous endings (i.e.I take coffee with cream and dog), expecting to see a P300 to the unexpected sentence-final words. However, instead of eliciting a large positivity, these anomalous endings elicited a large negativity, relative to the sentences with expected endings (i.e. He returned the book to the library) In the same paper, they confirmed that the negativity was not just caused by any unexpected event at the end of a sentence, since a semantically expected but physically unexpected word (i.e. She put on her high-heeled SHOES) elicited a P300 instead of negativity in the N400 window. This finding showed that the N400 is related to semantic processing, and is not just a response to unexpected words.
Ladies and gentlemen! Ladies and gentlemen
This, is truly an event
Nelly Nel, Jazze Phizzle, Jazz Phiza-fel
(Na-nana-na, nana, nana, nana) Woooo-eee!
(Na-nana-na, nana, nana, nana) Woo, woo, woo, oh boy!
(Na-nana-na, nana, nana, nana) Oh boy! Ohhh!
Hey, hey hey hey hey hey hey
Well uh-huh, well uh-huh girl I'm parked outside
And you know that it's sittin on chrome, chrome (uh-huh)
Hey, I'm just lookin for a pretty young thang
that uh, I can take home (take home)
Can we leave hurr (yeah) can we leave hurr (yeah)
Can we leave hurr (yeah) can we leave hurr - shorty can we
leave hurr (yeah) can we leave hurr (yeah)
Can we leave hurr (yeah) can we leave hurr (yeah)
I'm throwin nuggets out the fellow I push to Carmello
Yellow on yellow flooded the band and the bezel
Hear me now! Oh, no, did you see the hue?
I took the Phantom to the Opera, same van roll through the ghetto
Can we leave hurr? Shorty need to make up her mind
I seen them niggaz over there, but they ain't takin my shine
Got 7 niggaz tryin to be me, out here breakin they spine
But they got 7 different levels for they minions to mind
I want you both shorty (oh) go get it crunk shorty (oh)
I see your A-T-L stamp and go' head and stomp shorty (oh)
I got that shake now, and don't be scared now
Cause we can come from the kitchen up to that bed now
Shit it ain't nuttin to a boss, I heat you like air off
It ain't nuttin, they ain't cuttin, they frontin, that's they loss
Cause the, 'Tics is good, and the van is paid off
And I done got so damn cocky I took that Band-Aid off
Uhhhhhhhh, picture perfect, I paint a perfect picture
Third album, same focus, my intent is to get richer
I'm with my dirty Jazze Phizzle, he yieldin that instrumental
Youse a cold-ass nigga on the track (SHO' NUFF!)
Man - I'm tired of poppin these bottles, tired of fuckin these models
I'm tired of these menage-a nights - yeah right (PSYCH!)
I was built for it, I got hip for it
I even got a little swagger in my limp for it
I done had, sex in the city plus sex in the country
You know - sex in the zoo di-rectly behind the monkeys
Hold up! Don't get me wrong, I'm lookin for Ms. Right
But tonight ain't the time, I'm lookin for right now
It's two-thousand-fo', I'm in a new home
Threw out the Bentley bought a Double R {?}
It's like I'm holdin on to permanent mistletoe, I think you been sittin low
I got a driver dirty, he come when the whistle blow
(Na-nana-na) I'm smoother than you know
(Na-nana-na) Cadillac do's and bank rolls
(Na-nana-na) I simply go places you can't go
Ain't see me in no Linc', but you know that derrty in Brougham
I be on my (grind-na-grind-na-grind-na-grind)
With my money on my (mind-my-mind-my-mind-my-mind)
Plus I'm still in my (prime-my-prime-my-prime-my-prime)
And we be smokin that (la-lala-lala-lala)