Speech planning during multiple-object naming: Effects of ageing

Abstract

Two experiments were conducted with younger and older speakers. In Experiment 1, participants named single objects that were intact or visually degraded, while hearing distractor words that were phonologically related or unrelated to the object name. In both younger and older participants naming latencies were shorter for intact than for degraded objects and shorter when related than when unrelated distractors were presented. In Experiment 2, the single objects were replaced by object triplets, with the distractors being phonologically related to the first object's name. Naming latencies and gaze durations for the first object showed degradation and relatedness effects that were similar to those in single-object naming. Older participants were slower than younger participants when naming single objects and slower and less fluent on the second but not the first object when naming object triplets. The results of these experiments indicate that both younger and older speakers plan object names sequentially, but that older speakers use this planning strategy less efficiently.

Acknowledgments

We thank Zenzi Griffin and an anonymous reviewer for helpful comments on an earlier version of this paper.

Notes

¹ In this and the following study by Griffin and Spieler (2000, 2006), a word was considered disfluent when it was preceded by a silent pause (over 200 ms), a filled pause (“um” or “uh”), a false start (“the gira- zebra”), a stressed article (“thee”), or when it was corrected (“the giraffe, zebra”).

² Analyses of the error rates in Experiment 1 and of the error and pause rates in Experiment 2 were also performed on the arc-sine transformed data. These analyses yielded the same results as the reported analyses.

³ In Experiment 3 of Meyer et al. (2007), we only reported the young participants' utterance latencies and left-object gaze durations. We did not report the measures for the right object (i.e., naming latencies and gaze durations) or the speech duration and pause measures reported here. In the present paper, we offer an in-depth examination of how speakers plan their speech during a multiple-object naming task and of how older speakers differ from young speakers in their speech planning.

⁴ The results for the naming latencies for the right object were identical to those for the gaze durations for the right object. We therefore only report the results for the latter measure.

⁵ Analyses of variance with degradation and relatedness included as independent variables did not change the results. We report the results of the analyses in which these two variables were not included for reasons of consistency, since in analyses reported later, in which trial type (pause vs. no-pause) was included as an independent variable, the additional inclusion of degradation and relatedness resulted in empty cells for 3 participants. Instead of excluding the responses from these participants, we conducted the analyses on the responses averaged across the four experimental conditions.

⁶ We did not obtain information about years of education from the participants of Experiment 1. Therefore, we cannot rule out that the older participants of this experiment had fewer years of education than the young participants, and that this contributed to their longer speech onset latencies. However, they were recruited from the same participant pool as were the participants of Experiment 2 (who had stayed in education for longer than the undergraduates we tested), and we would certainly not expect a large difference in educational level.