Do Age of Acquisition and Orthographic Transparency Have the Same Effects in Different Modalities? (2022)

Abstract: This paper is intended to study the effects of age of acquisition (AoA) and orthographic transparency on word retrieval in Persian, which is an understudied language. A naming task (both pictures and words) and a recall task (both pictures and words) were used to explore how lexical retrieval and verbal memory are affected by AoA and transparency. Seventy two native speakers of Persian were recruited to participate in two experiments. The results showed that early acquired words are processed faster than late acquired words only when pictures were used as stimuli. Transparency of the words was not an influential factor. However, in the recall experiment a three-way interaction was observed: early acquired pictures and words were processed faster than late acquired stimuli except the words in the transparent condition. The findings speak to the fact that language-specific properties of languages are very important.

## introduction the majority of research on word retrieval and recall are done only on few languages of the word such as english @xcite , dutch @xcite , french @xcite , spanish @xcite and italian @xcite . there are only few reports available in other languages of the world such as persian. age of acquisition (aoa) is known to have a strong effect on word retrieval. words which are learned earlier are usually processed faster than late acquired words @xcite . this finding has been replicated across several languages in where aoa effect interacts with orthographic transparency is another question. orthographic transparency refers to the level of consistency in grapheme to morpheme correspondence. for instance, the word car is orthographically transparent, while the word night is not. arbitrary mapping hypothesis (amh) @xcite posits that aoa effect is only observable in words where print to sound correspondence is inconsistent (opaque). they believe that aoa effects is diminished in the transparent orthographies. findings from highly transparent orthographies in other languages such as turkish failed to replicate the predictions of amh @xcite . the aim of this paper is to see if previous findings could be replicated in persian which is an understudied language. persian orthography is both opaque and transparent thus allowing researchers to test aoa effects within one single language. this report is intended to see if aoa interacts with transparency similarly across both naming and recall tasks. if predictions of arh are correct, it is hypothesized that in both modalities (words vs. picture) of naming and recall tasks aoa should only show an effect in the opaque condition. in the transparent condition, aoa effect should disappear based on arh predictions. ## results linear mixed effect (lme) modeling is gaining popularity in psycholinguistic research. lme modeling offers several advantages over the classic statistical analyses. lme modeling takes into account item and subject random effects which leads to higher generalizability of findings to the larger population and stimuli @xcite . in this study, lme4 package ( https://cran.rproject.org/web/packages/lme4/) was used in r software (r development core team, 2012) in order to analyze the data in both experiments. ## discussion and conclusion regardless of the interaction patterns, the significant effect of aoa in this report is in line with many previous picture naming studies in other languages @xcite and persian @xcite . words and pictures which were learned earlier were processed faster and recalled more accurately than the late acquired stimuli regardless of the modality. however, the existence of interactions in both the reaction time and recall analyses reveals that aoa effect is more complicated than a simple main effect. the results of the reaction time experiment are not consistent with previous studies. first, there was no interaction between aoa and transparency predicted by amh @xcite . second, aoa had a significant effect only in the picture naming modality, while the effect disappeared in the word reading modality. it is believed that aoa is a fundamental property of lexical retrieval and is independent of the modality. in other words, no matter whether the stimuli are presented as print or picture, the effect should be there. this is a counterintuitive finding which needs further investigation in the future studies. the results from the recall experiment are partially consistent with ahm. although, transparency and aoa did not have any interaction in the picture recall, the interaction observed in the word recall is consistent with ahm predictions. based on ahm predictions, the aoa effect disappeared in the transparent condition. what is still counterintuitive is that why this effect is only observed in word recall and not in picture recall. if aoa effect is independent of modality, a similar effect should have been witnessed in both modalities. we did not control for other variables such as imageability, visual complexity, familiarity, and frequency. it's possible that the effects observed in this study could be attributed to lack of control over these variables. the number of items was not too many limiting the power of the study and hence generalizability of the findings. moreover, the participants in the reaction time and recall experiments were different which could be another limitation due to lack of control over interindividual variability. for these reasons, we believe our findings should be interpreted with caution. however, the counterintuitive findings could pave the way for future studies in other languages. we need more studies with null or counterintuitive effects indeed. the data and codes for this manuscript are available at the following doi 10.17605/osf.io/rtph6.