“Proactive” in many ways: Developmental evidence for a dynamic pluralistic approach to prediction

Abstract

The anticipation of the forthcoming behaviour of social interaction partners is a useful ability supporting interaction and communication between social partners. Associations and prediction based on the production system (in line with views that listeners use the production system covertly to anticipate what the other person might be likely to say) are two potential factors, which have been proposed to be involved in anticipatory language processing. We examined the influence of both factors on the degree to which listeners predict upcoming linguistic input. Are listeners more likely to predict book as an appropriate continuation of the sentence “The boy reads a”, based on the strength of the association between the words read and book (strong association) and read and letter (weak association)? Do more proficient producers predict more? What is the interplay of these two influences on prediction? The results suggest that associations influence language-mediated anticipatory eye gaze in two-year-olds and adults only when two thematically appropriate target objects compete for overt attention but not when these objects are presented separately. Furthermore, children's prediction abilities are strongly related to their language production skills when appropriate target objects are presented separately but not when presented together. Both influences on prediction in language processing thus appear to be context dependent. We conclude that multiple factors simultaneously influence listeners’ anticipation of upcoming linguistic input and that only such a dynamic approach to prediction can capture listeners’ prowess at predictive language processing.

Keywords:

• Prediction
• Associative strength
• Vocabulary development
• Production
• Children

Notes

¹The verb klettern [climb] was strongly associated with Rutsche [slide] and less strongly associated with Berg [mountain] for children, while the reverse was true for adults. Our assignment of items to conditions, therefore, took this into consideration and differed across the adult and child version of the experiment. Excluding this item does not change the pattern or the significance of the results.

²Not all children were reported to know all the words presented to them in the experiment, at least according to parental reports. While parental reports have been shown to underestimate word knowledge (Houston-Price, Mather, & Sakkalou, 2007), we, nevertheless, carried out a reduced analysis removing any trials where children were reported not to comprehend either the target or distractor image or the verb. This reduced analyses yielded very similar results compared to the main analyses. In particular, there was a significant main effect of window in the 2 × 2 ANOVA comparing the strong and the weak association condition, F(27) = 9.35, p = .005,  = .26, with no significant interaction between condition and window, p > .8. There was also a significant increase in fixations to the strongly associated image from the baseline to the verb window in the conflict condition, t(27) = −2.92, p = .007.

³We suggest that the data from conflict trials and the strongly and weakly associated trials ought not to be analysed together due to differences in the relationship of “target” and “distractor” images across these trials. However, one could have an a priori hypothesis about the strongly associated image being more appropriate than the weakly associated image and, therefore, more suitable as a target. Therefore, we analysed the data in a 3 × 2 ANOVA with condition (conflict, strongly associated, weakly associated) and window (baseline, verb) as within-subjects factors. This analysis yielded highly similar results to the main analyses reported for both children and adults. In particular, there was no significant interaction between window and condition, p = .8. Nevertheless, we maintain that this is a less preferable method of analysing the data due to the a priori assumption that the strongly associated image is the target.

⁴We could not obtain vocabulary data from two children who are, consequently not included in these analyses. We also excluded one child whose vocabulary scores were more than 2 standard deviations below the mean—that is, this child was reported to comprehend 39 words and produce 34 words. Further analysis of the data from this child suggested that the caregiver predominantly marked the child as comprehending a word only when the child also produced this word. Note that the pattern remained highly similar for both strongly and weakly associated trials even when the data from this child were included.

⁵This corpus includes data from 22 normal hearing children whose interactions were recorded at five points between 1;4 and 2;10 years of life. We included all mentions of the label across all data points at 1;4, 1;8, 2;1, 2;5, and 2;10 years of age.

⁶We note, however, that this is precisely the reason why we included a baseline phase in the experiment since were children to merely fixate the image of the more frequent label (in six out of 10 trials), then this preference should also be present in the baseline phase. Any increase from the baseline to the verb phase, therefore, excludes fixations driven by a putative preference for the more frequent image.