Cascaded processing develops by five years of age: evidence from adult and child picture naming

ABSTRACTAlthough there is compelling evidence for cascading activation in adult lexical planning, there is little research on how and when cascaded processing develops. We use a picture naming task to compare word planning in adults and five-year-old children. We manipulated image codability (name agreement) and name frequency, factors that affect lexical selection and phonological encoding, respectively. These factors had qualitatively similar influences on naming response time in both populations, suggesting similar underlying planning processes. Critically, we found an under-additive interaction between codability and frequency such that the frequency effect was attenuated when name agreement was low. This interaction generalises across experiments and languages and can be simulated in a planning architecture in which phonological forms become activated before lexical selection is complete. These results provide evidence for cascaded processing at an earlier age than previous studies, suggesting that informational cascades are a fundamental property of the production architecture.KEYWORDS: Language productioncascaded processingword planningname agreementcodabilityfrequencylanguage acquisition AcknowledgementsThank you to Parker Robbins and Benazir Neree for their assistance with data collection and processing as well as to Alfonso Caramazza and Joshua Cetron for sharing their thoughts on the project and analyses. We are additionally grateful to the anonymous reviewers of this article for their helpful comments.Disclosure statementNo potential conflict of interest was reported by the author(s).Data availability statementData and Supplementary Materials are available from https://osf.io/myrtg/.Notes1 Reconciling the mixed error effect with a serial model of lexical planning (e.g. Levelt et al., Citation1991) requires the assumption of a post-encoding editor (Baars et al., Citation1975; Butterworth, Citation1981; Kempen & Huijbers, Citation1983; Levelt, Citation1989).2 It is important to note, however, that codability effects, while commonly attributed to co-activation at the lexical level, may not exclusively reflect an influence on lexical decision; name agreement may also influence processes prior to lexical decision such as conceptual access.3 One exception we have found is an adult sentence production study by Spieler and Griffin (Citation2006). Their experiment elicited sentences in the form The A and the B is above the C. The researchers manipulated the frequency (high, low) and codability (high, medium) of critical items that appeared in either the B or C position (the item in A always had high codability). They observed an interaction between the frequency and codability of the critical items on the latency between the onset of A and the onset of the critical item. This interaction is not in the direction we observe, however: they observed an over-additive effect of frequency for medium codable items compared to highly codable items (latencies were especially slow for low frequency, medium codable items). While not extensively discussed in Spieler and Griffin (Citation2006), they similarly attribute such an effect to cascading activation (see discussion in Griffin & Bock, Citation1998 about how increased constraint in word choice may attenuate the influence of frequency).4 The power analysis was performed using the random effects structure specified in our preregistration.5 The adult preregistration lists the use of an adjective as a potential example of prenominal verbalisation. Given that some of the stimulus images elicited responses with adjectives that modified the head noun such that the response could potentially be considered a single lexical item (e.g. a compound noun) with a different meaning than the head noun (e.g. school bus, steering wheel, candy bar), we decided to allow adjectives in the responses.6 We altered the model structure specified in the preregistration to (i) make our model estimates more conservative and (ii) aid in model convergence. We added a random intercept for item as well as an interaction term in the random slope by subject, and we omitted the random effect of trial (an investigation of participant slopes for trial suggested minimal variation in trial slope by participant).7 The large τ effect in the child data is unlikely to be solely attributable to the imbalance in target name frequency between the child codability conditions (Table 3). The adult data suggest that an effect of frequency should influence τ and µ roughly evenly, meaning that the lower frequency of the low child codability condition should not have disproportionately inflated the τ effect above the µ effect.8 Bates et al. (Citation2003) also elicited data from native speakers of Bulgarian, however we decided to exclude this language from our analysis, as the frequency measure provided was in the form of subjective ratings instead of derived from corpus counts. It is not clear that we should expect a frequency measure on an ordinal scale to show the same interaction with H score as the frequency score measure used in Study 1.9 As pointed out by a reviewer, under some assumptions, cascading activation may in fact predict an over-additive interaction. In particular, over-additivity could arise if (i) phonological encoding begins as soon as lexical candidates are active, (ii) phonemes linked to different lexical candidates compete with each other (but phonemes activated by the same candidate do not), (iii) phonological competition depends on frequency (high frequency competitors result in greater competition), and (iv) in cases of low name agreement, the frequency advantage for the produced name relative to alternatives is greater for high frequency words than low frequency words. Under these assumptions, competition during phonological encoding would have a minimal effect on high frequency, low codability items and the largest effect on low frequency, low codability items, thereby resulting in an over-additive interaction. Our data are inconsistent with this hypothesis.Additional informationFundingThis work was supported by an internal grant from Harvard University, FAS Psychology.