It has been demonstrated that parental reminiscing plays an important role in preschoolers' cognitive development among which memory (Waters \& al., 2019). Specifically, both correlational and interventional studies show that children of parents using a high-elaborative style during reminiscing (i.e., frequent, detailed and collaborative discussions about the past) recount their memories in a more detailed and coherent way (Wu \& Jobson, 2019). Besides, some correlational studies (e.g., Langley et al., 2017) seem to also reveal an effect of parental reminiscing on children's ability to learn new information, as assessed in clinical neuropsychology by episodic memory tasks. However, the mechanisms underlying these influences are currently unclear. Indeed, several non-mutually exclusive hypotheses are frequently suggested (e.g., among which the development of metacognition (Rudek \& Haden, 2005)) but, to date, have never been tested. Identifying these mechanisms could contribute to design interventions targeting parental reminiscing and to determine in which clinical contexts to use them. Currently, interventional studies in the field are scarce (for a review, see Corsano \& Guidotti, 2019) and lack of consensus.

The primary aims of the present study are multiple. First, we aim to evaluate the effectiveness of a brief intervention program to improve the way parents reminisce with their child. After the intervention, we expect an increase in the frequency of use of the targeted behaviors and thus an increase in the level of parental elaboration. The second goal of this study is to explore the effects of the improvements in parental reminiscing style on children's memory skills, both autobiographical memory (i.e., ability to recount one's own memories) and episodic memory (i.e., ability to learn new information). Regarding autobiographical memory, we anticipate to replicate the results shown in other interventional studies (i.e., an increase in the amount of information reported by children at the end of the intervention; for a review, see Corsano \& Guidotti, 2019). Regarding episodic memory, based on the results of correlational studies (e.g., Léonard et al., in prep), we anticipate after the intervention to show among children an improved ability to learn new information. Beyond these primary aims, secondary aims are also targeted in this study. Currently, the mechanisms underlying the relation between parental reminiscing and child's memory are still relatively unknown. A hypothesis that is frequently suggested is the development of metacognition (Rudek \& Haden, 2005). One purpose of this study is to test this assumption by focusing on 2 metacognitive skills that develop during the preschool years: (a) the ability to make confidence judgments, (b) the ability to use the memorability-based heuristic. After the intervention, we expect children to make more accurate confidence judgments and to use more successfully the memorability-based heuristic to guide their memory decisions. Therefore, we may obtain information on the active ingredients of the relation between parental reminiscing and memory. Then, in an exploratory way, we explore whether such an intervention could improve parental cognitions as well as parents' perception of reminiscing with their child. We anticipate an improvement in parental cognitions and a more positive perception of reminiscing. Finally, we are interested in assessing parents' adherence to the intervention by exploring their feelings about its format, content and feasibility in daily life.

For all these purposes, a randomized controlled trial is currently being conducted. 2 experimental groups have been created and parent-child dyads were assigned to one of them using a stratified randomization on children's age and when possible on children's gender. Participants from both groups begin the study with an assessment of all variables of interest (i.e., baseline1). Immediately after this baseline assessment, participants from Group 1 receive the intervention. Participants from Group 2 (i.e., a waiting-list group acting as a control group) receive exactly the same intervention but later (i.e., after a second baseline assessment which is held after the completion of the intervention by the Group 1). Approximatively 2 weeks after the intervention, the dyads in each group undergo a post-intervention assessment (i.e., follow-up 1; similar to the baseline assessments). Besides, 6 months later, the Group 1 will participate in a follow-up session to check the persistence of the effects over time (i.e., follow-up 2). If the intervention is successful, this long-term follow-up may allow us to show either the maintenance of effects over time (e.g., an increase in parental elaboration) and/or the appearance of some effects (e.g., effects on child outcomes due to the time it takes for the improvement in parental style to have an effect on them).

In this study, all parents are provided with an 8-session intervention (i.e., 1 session/week) targeting different aspects of parental reminiscing: (a) the promotion of child participation (e.g., through parent's use of feedbacks), (b) the structure of reminiscing (e.g., parent's use of open-ended questions) and (c) the content addressed during reminiscing (e.g., contextual information). Parents learn to use the target behaviors through different standardized techniques: (a) psychoeducation, (b) modeling and (c) supervised practice. Due to Covid-19 epidemic, the intervention is held completely online (i.e., 4 e-learnings and 4 videoconferencing sessions).