Language comprehension

Language comprehension

understanding speech • differentiating speech sounds from other noises • recognizing words • activating their syntactic and semantic properties • building a grammatical structure • interpreting this structure

building a grammatical structure? Do we need to do that? Well, consider this: Man bites dog.vs. Dog bites man.

… and how about this? Police kill man with TV tuner. Life means caring for hospital director. Retired priest may marry Springsteen. Kicking baby considered to be healthy. Brand door kaars geblust. Slingerend in een jeep heeft de politie vrijdagnacht een 45-jarige Zeisterse staande gehouden. De burgemeester ging na het telefoongesprek met de officier van dienst naar bed.

upshot • the intended meaning and the funny meaning do not result from different word meanings or sth. • rather, they derive from different arrangements of words into word groups (phrases) • so, structure determines meaning • so, yes, structure building (parsing) is a necessary component of language comprehension

ambiguity S NP VP V NP PP He hit the man with the binoculars

ambiguity S NP VP V NP NP PP He hit the man with the binoculars

parsing algorithms • wait-and-see • parallelism • conservative guessing

wait-and-see • take in words up to a natural boundary (e.g. sentence ending), and then try to arrange them into a structure, following the grammatical rules • comprehension will arise after a sentence has ended • but: we feel we often know how somebody else’s sentence will end • and, if a sentence is interrupted, we nonetheless understand what was said

parallelism • at any bit of input, create all structures that are compatible with it • prediction: the competing structural representations for an ambiguous piece of input will all be kept in memory until disambiguating information comes in • problem: ambiguity is ubiquitous in natural language, and memory is limited

(conservative) guessing • at any bit of input, attempt to build as much structure as possible • prediction: mistakes will be made, and retracing (repairing) will occur

incremental parsing Sentence subject He

incremental parsing Sentence subject verb phrase V He

incremental parsing Sentence subject verb phrase V He gave

incremental parsing Sentence subject verb phrase V ind.obj. dir.obj. He gave her

incremental parsing Sentence subject verb phrase V ind.obj. dir.obj He gave her flowers

incremental parsing Sentence subject verb phrase ??? ??? ??? V ind.obj. dir.obj He gave her flowers to his mother

incremental parsing: repair Sentence subject verb phrase ind.obj. V dir.obj He gave her flowers to his mother 3 2 1 herperspro herposspro

initial attachment decisions • Garden Path Theory:attach incoming words to the evolving structure in the most economic way, I.e., without involving building blocks the necessity of which is unclear.

for example He hit the man with the binoculars. The structure in which “the binoculars” is the instrument of “hitting” has one node less than the structure in which it is an attribute of “the man”.

economic S NP VP V NP PP He hit the man with the binoculars

less economic S NP VP V NP NP PP He hit the man with the binoculars

parsing strategies • minimal attachment • late closure • active filler strategy  ECONOMIZE

the most famous garden path The horse raced past the barn fell. (The horse that was raced past the barn fell.) Tom Bever, 19..

the parser wants to do this: S minimal attachment NP VP V PP The horse raced past the barn

…but it has to do this: non-minimal attachment S NP VP NP S V V PP The horse raced past the barn fell.

how about this? John said the man will die yesterday. late closure

another nice one While she was mending the sock fell off her lap. what the parser likes: late closure

another nice one While she was mending the sock fell off her lap. what the parser has to do: early closure note: since ‘while’ introduces a subordinate S, the main S is expected anyway: minimal attachment is irrelevant

Keep in mind that … …the garden path model assumes that structural (syntactic) analysis is prior to, and independent of, semantic and pragmatic interpretation!

Is this correct? • priority? • autonomy (modularity)?

a note on measurement • Sometimes a garden path (i.e. parsing difficulty) is consciously noticeable, like in the horse raced example. • However, language is full of ambiguities, and the majority go by unnoticed. • So how can we, in such cases, determine whether the sentence processor has a problem?

time • The answer lies in the assumption that every bit of work the sentence processor does takes some time. • If the processor is garden-pathed, it will have to retrace and correct its previous decisions, in order to accommodate the incoming words that don’t ‘fit in’. • This we can measure by the time it takes to process the critical words.

self-paced reading The ----- ----- --- ------ ---- --- ---- ---. --- quick brown --- ------ ---- --- ---- ---. --- ----- ----- fox ------ ---- --- ---- ---. --- ----- ----- --- jumped over --- ---- ---. --- ----- ----- --- ------ ---- the ---- ---. --- ----- ----- --- ------ ---- --- lazy dog. --- ----- ----- --- ------ ---- --- ---- ---. --- ----- ----- --- ------ ---- --- ---- ---.

self-paced reading de moeder van de kleuters die zwaaide/en naar de vertrekkende bus vergat …

eye-movement recording

the priority issue

relative clauses are ambiguous … in Dutch: Karel hielp de mijnwerker die de man vond.Karel helped the mineworker REL the man found ‘mijnwerker’ and ‘man’ can both be finder and ‘findee’ in other words:“die”, which refers back to “mijnwerker” can be both subject (subject-relative) and object (object-relative)

subject-relative is preferred • Karel hielp de mijnwerkers die de man vonden.Karel helped the mineworkers-PL REL the man-SG found-PLplural verb needs plural subject; “die” = subject • Karel hielp de mijnwerkers die de man vond.Karel helped the mineworkers-PL REL the man-SG found-SGsing. verb needs sing. subject; “die” = object • Less errors, shorter reading times, for 1 than for 2

subject-relative is preferred Explanation: readers want to analyse the relative pronoun (“die”) as the subject of the embedded clause, due to the Active Filler Strategy (I.e., this is the most economic option) if “die” turns out to be the object, the processor has to re-analyze Frazier 1987

Mak 2001 • … moeten de inbrekers, die de bewoner beroofd hebben, nog een tijdje op het … • … moet de bewoner, die de inbrekers beroofd hebben, nog een tijdje op het … • … moeten de inbrekers, die de computer gestolen hebben, nog een tijdje op het … • … moet de computer, die de inbrekers gestolen hebben, nog een tijdje op het …

Mak 2001 • … inbrekers, die de bewoner … hebben …SR; animate - animate • … bewoner, die de inbrekers … hebben …OR; animate - animate • … inbrekers, die de computer … hebben …SR; animate - inanimate • … computer, die de inbrekers … hebben …OR inanimate - animate 350 386 347 336 ms. on aux + 1

summary • when the two nouns are both animate, SR is faster than OR • when there is a difference in animacy, the difference in reading time disappears  animacy helps deciding which of the two has to be the subject – immediately NO REANALYSIS

upshot • Mak has shown that semantics (the animacy factor) has a very early effect on parsing decisions. • So it would seem unlikely that semantic interpretation really follows structural analysis. • Rather, it looks like the two work in tandem. … but one could argue that the measurements are not sufficiently sensitive…

does this mean that … … syntactic and semantic analysis are basically the same process?

the independence issue

the brain … … appears to provide an answer to this question

event-related potentials

Language comprehension