Older Adults’ More Effective Use of Context: Evidence from Modification Ambiguities

Robert ThorntonPomona College

Method•Participants: 32 young and 32

older adults

•16 items, VP-NP modification ambiguities.

•Single word, self-paced reading

•Three main factors:

1.Contextual expectation (VP modification vs. NP

modification)

2.Disambiguation (VP modification

vs. NP modification)

3.Age (young vs. older adult)

BackgroundA central topic in Psycholinguistics has been: how do context-based expectations affect sentence processing? (e.g., Altmann & Steedman, 1988; Sedivy, 2002).

This work has shown robust effects of context, but mostly on younger adults, with little developmental work. Thus, an open question is: do interpretive processes in sentence processing change with normal aging?

Work on individual differences suggests that it might. Pearlmutter & MacDonald, (1995) found that low span readers are less able to use contextual information in resolving syntactic ambiguities. As working memory span decreases with age (e.g., Bopp & Verhaeghen, 2005), we might expect older adults to be less able to hold contextual expectations in memory during comprehension.

However, work in the aging literature shows similar or larger effects of semantic variables for older adults (e.g., Burke & Laver, 1993; Radvansky et al., 2001), so we might expect larger effects of context.

Specific Aim: To examine how the use of contextual constraints changes as a function of normal aging.

Sample Item

Contextual Expectation

VP Modification Expectation:

The handyman wasn’t sure which tool to use first, so he fixed the television with…

NP Modification Expectation:

The handyman wasn’t sure which television to work on first, so he fixed the television with…

Disambiguation

VP Modification:…with a soldering iron

NP Modification:…with a broken screen

DiscussionAs with previous studies, for younger adults, the context manipulation could eliminate the VP modification preference, but it couldn’t reverse it.

However, older adults showed a greater effect of the contextual expectation for NP modification, in that a significant NP modification preference arose.

One possible explanation for the effect is general slowing (e.g., Myerson et al., 1997): because older adults responded so much more slowly, top down contextual information had longer to build in strength and affect initial comprehension. Alternatively, the result could be explained by an increased number of semantic connections in memory with age (e.g., Laver & Burke, 1993).

Results

Significant results appeared on the word following the disambiguation, e.g., …with the soldering iron before…

Main effect of age: Young adults read faster than older adults (424 ms/word vs. 819 ms/word), F (1, 62) = 74.65, p < .001.

Main effect of disambiguation: Overall, VP modification resulted in shorter RTs than NP modification, F (1, 62) = 11.33, p < .001 Expect x Disambig: Strong VP modification preference with the VP contexts, no preference with the NP contexts, F (1, 62) = 22.03, p < .001

3-way interaction: On top of the 2-way interaction, older adults showed a significant NP modification preference with the NP contexts, young adults showed none, F (1, 62) = 5.47, p < .05

Strong VPPreference

With NP Context,No Preference

Same VPPreference

For olders, a sig. NP pref.