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Informal research
description
How do people manage
to speak? That is, how do they take some idea that isn't expressed in
words and express it out loud? Right now we in the Cognition and
Communication lab are particularly concerned with the timing of it all.
Many people have assumed that fluent speech requires advanced planning
- that speakers decide pretty far in advance which words to use and the
order in which they will say them. Recent work in the lab has focused
on showing that people don't prepare words far in advance of saying
them, even when they sound perfectly fluent (like news-anchors).
Instead, people often make decisions about what to say next and which
words to use at the last possible moment. If they are lucky, the timing
works out so they sound fluent. Often though, speakers are disfluent -
meaning that they pause in the middle of sentences, stretch words out,
restart sentences, or say "uh" or "um". When speakers are particularly
concerned about sounding fluent, they seem to estimate how little
advanced planning they need to do to have words ready to say when
needed. These estimates increase the likelihood that speech will be
fluent, but these estimates can be sometimes wrong.
A fun and challenging aspect of the research is that we don't know
what ideas look like, so we don't know what speakers start with when
they speak. However, to get interpretable results, we often have to
make sure that multiple speakers start off with the same ideas and end
up saying the same sentences. This makes it necessary to come up with
new ways of creating and changing the ideas that speakers express, and
new ways of measuring the processes we think are involved in speaking.
One of the new methods is to have people describe pictures while we
monitor when they look at different objects in the pictures. Under
these circumstances, people tend to look at objects during the second
before mentioning them. In other words, their eyes are about a second
ahead of their mouths. Monitoring what speakers look at seems useful
for predicting what they will talk about and when they prepare the
names of objects. We can then use this information to figure out more
about other aspects of speaking.
So general questions of interest in the lab are: How does language
production work? How are conceptual representations mapped on to words
and phrases? What determines the grammatical roles that words and
phrases occupy in a sentence? What are the computational properties of
the production system that underlie relatively error free speech? How
might processes of language production and comprehension be related?
What features might language production share with other cognitive
processes? How is the sequencing and timing of word production in
speech related to the sequencing and timing of motor movements in other
activities (such as dancing)? How do individual differences such as age
and dialect affect word choice and the timing of speech?
Current projects investigate the time course for selecting words and
making syntactic decisions when producing sentences, how speakers
monitor their speech preparation and vary their degree of planning, how
the cognitive changes associated with normal aging affect language
production, and cross-linguistic studies of production, particularly
word order.
We study these questions and others using traditional measures of
performance such as response latencies and response probabilities, in
addition to eye movement data. Computational modeling of existing data
provides predictions for future research.
Click on these links for more on
last
updated 9/03
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