Datensatz

Zusammenfassung

Experimentally induced disruptions provide a window
into processes underlying speech production. Studies
exploiting this technique have tended to focus on lexical
access, where evidence is compatible with parallel
influences of unselected and intended words on
processing (Macleod, 1991). Another issue concerns
cascade between lexical access and articulation. Cascade
models predict that disruptions to lexical access should
produce corresponding disruptions to articulation
(Goldrick & Blumstein, 2006), however the evidence for
such effects is mixed (Damian, 2003; Kello, 2000). These
conflicting results could result from individual differences
in the stability of processing. When individuals
experience high degrees of disruption to lexical access,
they will be unable to discretely select a target
representation for production. This will allow distortions
arising in lexical access to influence articulation. We
tested this hypothesis by varying the degree of disruption
of lexical access induced by a paradigm that results in
semantic substitution errors in picture naming (Ferreira &
Griffin, 2003). In Experiment 1, we examined young
adult monolinguals; the high level of stability associated
with speech production in young adults is predicted to
result in weak interactive effects. Two additional
experiments were then conducted to examine whether
more robust interaction is found when speech production
is further destabilized. In Experiment 2, a separate group
of younger adults performed the cloze sentence
completion paradigm under time-pressure. In Experiment
3, we examined a group of older adults, where the effects
of normal cognitive aging on lexical access may naturally
increase disruptions at articulation. Our hypothesis
predicts there will be increased disruptions to articulation
in Experiments 2 and 3 relative to the baseline of
Experiment 1. We will discuss the results and consider the
implications of our findings for a dynamic account of
interaction during speech production.