STAGES OF COMPREHENSION
discourse modelling
semantic analysis
syntactic “parsing”
lexical access
phonemic analysis
sensory processing
THE IMMEDIACY PRINCIPLE
OF LANGUAGE
COMPREHENSION
• comprehension involves building a
“model” of meaning, based on
– word type, meaning and order
– prior context and prior knowledge
• to minimize load, build as much of
this structure as possible “on line”
– resolve ambiguities as they’re
encountered:
• lexical: PLANE?
• syntactic: visiting relatives can
be difficult
• this can result in “garden path”
errors
– the conductor stood before the
audience left the hall.
– after visiting his parents left.
Headline Ambiguities
–
–
–
–
–
–
Man charged with battery
Czech leader meets with opposition
Teenage prostitution problem is mounting
Lawyers let fly in court
Police: Fighting robber is foolish
The police officer saw that the lightning
bolt hit the child and dialed 911..
– Bill banning nude dancing on governor’s
desk
– American man sentenced to 10 years in
Scotland
CONTEXT AND WORD
RECOGNITION SPEED
Fischler & Bloom, 1979
Task: read sentence context frames,
“As soon as they entered the room, they
turned on the . . “
then make word-nonword decision to:
TYPE OF
COMPLETION example
speed of
lexical decision
expected
unexpected
incongruous
nonword
600 msec
650 msec
800 msec
910 msec
LIGHT
SWITCH
SNAKE
SNOBE
CONTEXT EFFECTS AND THE
“N400” (Kutas & Hillyard, 1981)
task: read sentences while EEG is
recorded and later averaged:
• semantically unexpected completions elicit a
negative “wave” peaking at 400 msec after
word onset (N400)
• differences can be seen as early as 250 msec
after onset
DOES CONTEXT AFFECT
“LEXICAL ACCESS?”
Swinney, 1979
task: listen to spoken sentences,
watch for word/nonword strings
“. . the
electronic
detector
found
a
bug
200 msec
in
700 msec
the
.
..“
SPY
or
or
or
ANT
PEN
WID
at 200 msec, both SPY and ANT faster than PEN
(so: access of both meanings of homophone)
at 700 msec, only SPY is faster than PEN
(so: rapid selection of appropriate meaning)
SYNTACTIC STRUCTURE AND
SENTENCE PROCESSING
• perceived location of “click” drifts
toward clause boundaries:
– “ . . the man who cheated lost the hand.”
actual reported
• perception of rapidly shown
sentences better if words are grouped
in syntactic constituent “chunks”:
– The man
who cheated
in class
lost
vs
The
man who
cheated in
class lost
SYNTAX, EFFORT, AND EEG
(King & Kutas, 1995)
subject-relative:
“The secretary who gladly married
the senator typed the letter”
object-relative:
“The secretary who the senator
gladly married typed the letter”
A “MINIMAL ATTACHMENT
STRATEGY” FOR BUILDING
SYNTAX (Frazier, 1979)
attach each new phrase to the current
“node” if possible (“late closure”)
as in (A):
VP
PP
NP
V
NP
The spy saw the cop with the binoculars..
but not in (B):
VP
NP
NP
V
NP
PP
The spy saw the cop with the revolver . .
(B) takes longer to read (Rayner &
Frazier, ‘83) - though (A) is ambiguous
SYNTACTIC STRUCTURE AND
SEMANTIC PROCESSING
• Meaning can constrain parsing:
The bird saw the cop with the binoculars
Read as quickly as (A) above
(C) The cop [that was] arrested by the
detective was guilty of taking bribes
(D) The crook [that was] arrested by the
detective was guilty of taking bribes
(C) Is read more slowly; (D) no more
difficult than the “unreduced” version –
why?
[McRae et al, 1998]