Metacognitive abilities and self-knowledge are necessary for psychological maturation and good mental functioning of individuals. It is generally agreed that an adequate representation of oneself and others is essential to establish functional interpersonal relationships. These metacognitive abilities are not adequately developed in patients with various mental health problems, such as personality disorders, eating disorders, psychosis, and depression, and are associated with the severity of the pathology.

Self-awareness is a central element that begins to consolidate during adolescence. For that reason, the investigators aim to evaluate the effects of immersive training on the metacognitive abilities and self-knowledge of young people. Based on the repertory grid technique (RGT), our research team has developed a brief immersive training to enhance metacognitive abilities. This intervention facilitates the exploration of personal identity in a safe environment. Specifically, it is an immersion in the person's own world of meanings using Virtual Reality (VR), with the Explore Your Meanings (EYME) tool, a technological platform created to help mental health professionals to enhance the personal development and therapeutic change of their clients. Expected results include an increase in participants' self-concept clarity, metacognition, and reflective function as well as a deeper knowledge about their relationship with various aspects of self-knowledge and self-esteem.

INTRODUCTION

Metacognitive abilities and self-knowledge are necessary for psychological maturation and good mental functioning of individuals. Self-knowledge is a central element in cognitive and personality development that begins to be structured during adolescence and evolves during youth and even later stages. It can be considered as the "mental map" or theory people use to construe themselves, and others based on their personal experiences. Self-knowledge consists of the schemas or constructs people use to interpret events, organize their responses and actions, and for anticipating the future. The variables that reflect metacognitive abilities and self-knowledge are diverse in the scientific literature. The investigators highlight the following:

1. Self-concept clarity is understood as the degree to which the contents of the person's self-concept are clearly defined, with certainty, with consistency, and are experienced as internally and temporally stable (Campbell et al., 1996).
2. Metacognition refers to the ability to identify, understand and reflect on one's own and others' mental states (e.g., thoughts, desires, emotions) (Pedone et al, 2017).
3. Reflective Function (RF) refers to the operationalization of the mental processes underlying mentalizing (Katznelson, 2014), which is defined as the ability to understand or interpret one's own and others' mental states, either implicitly or explicitly (Fonagy & Bateman, 2008).
4. Self-knowledge is a broad term used in several studies (e.g., Carapeto & Feixas, 2020) and is understood as the construction of one's personality characteristics in relation to the constructs they perceive in others and to their own "ideal self".
5. Self-esteem is a classic concept, often related to the previous terms, referring to the person's evaluation of their self and their capabilities.

Given that a good development of metacognitive capacities and self-knowledge is considered fundamental for the optimal functioning of individuals and society, the investigators consider the need to generate tools and/or interventions that can improve and enhance their development to be essential. In accordance, several approaches are considered. Personal Construct Theory (Kelly, 1955) focuses on the study of personal identity, understood as the core constructs of a person, and offers valid instruments to enhance metacognitive abilities and transformative self-knowledge. Based on the repertory grid technique (RGT), our research team has developed a brief immersive training to enhance the described metacognitive capacities.

This intervention allows participants to explore their personal identity in a safe environment. Specifically, it is an immersion in the person's own world of meanings through Virtual Reality (VR), with the Explore Your Meanings (EYME) tool, a technological platform created to help mental health professionals to enhance the personal development and therapeutic change of their clients.

OBJECTIVES

The general objective of this research is to evaluate the effects of immersive training based on RGT and EYME on the metacognitive abilities and self-knowledge of young participants. The specific objectives are:

1. To verify the hypothesis that such training increases participants' self-concept clarity, metacognition, reflective function, and self-esteem.
2. To identify the relationships between these variables and their relationship with indicators of self-knowledge (e.g., current self/ideal self-discrepancy; cognitive conflicts) derived from the RGT.
3. To explore the general characteristics of the contents and structure of self-knowledge in young participants.
4. To examine the relationship of gender and other sociodemographic variables with the level of metacognitive capacities and self-knowledge in young participants.

PROCEDURE. Participants will be contacted by posting an announcement on Internet forums and social networks, asking to those interested in participating to access an online survey. The survey will begin with the informed consent form. After reading and accepting the informed consent, participants will be presented with sociodemographic questions, such as age, sex, country, employment, and marital status as well as whether they have a record of severe mental illness or substance misuse in the last year. As part of this initial assessment, the following questionnaires will be administered: LS, SCC, MSAS, RFQ-8, RSE, CORE-OM, and DASS-21 (see Outcome Measures Section).

Among those completing the survey, eligible participants will be invited to attend in person the three-session intervention. In all these sessions, the CORE-SFB will be administered at the beginning of the session to detect possible suicidal ideation. If so, the researcher in charge will deal with this problem (proposing referral, contact with family, or call to specialized services) instead of continuing with the investigation.

First session: The researcher will explain to the participant the purpose of the three sessions, which consists of increasing self-knowledge to promote personal development and growth. The family and relational context of the participant and possible difficulties or issues of concern will be explored as well as the areas that he/she believes can be improved by increasing his/her self-knowledge. A self-characterization (Kelly, 1955; Feixas & Villegas, 2000) will be requested as a homework assignment (minimum one paragraph, maximum one page) to be handed in during the following session.

Second session: As part of the intervention, self-characterization will be briefly discussed and the RGT applied using the digital platform EYME. It begins with a computer-assisted interview where the constructs of the participant are elicited and applied by means of a 7-point visual scale to the most significant people in their interpersonal world, in addition to the "self now" and the "ideal self" (Feixas, Alabèrnia-Segura & García-Gutiérrez, 2022). Other elements of the self or other constructs that appear relevant from the first session or in the self-characterization can be included.

Third session: The results of the data analysis provided by EYME will be discussed in terms of self-definition, possible areas for improvement, and discrepancies between the current self, the ideal self, and others, as well as possible internal conflicts. The constructs and significant people are visualized in a 3D space visible on a computer screen, in which the participant has an immersive exploration using VR, offering a powerful and clarifying experience about the person's schemas and perceptions of self and others, also with respect to their ideal image. The dialogue with the researcher during and after the immersive experience is oriented towards facilitating the assimilation of the information provided and its analysis, which may include upward laddering from one of the relevant constructs of the person (Neimeyer, 1993). At the end of the session, the LS, SCC, MSAS, RFQ-8, RSE, and DASS-21 questionnaires will be administered.

Follow-up assessment: One month after the third session (placed two weeks after baseline), the CORE-OM, SCC, MSAS, RFQ-8, RSE, LS, and CRES-4 instruments will be administered online.

DATA ANALYSES. The statistical analysis will be carried out with Stata 16.1 (StataCorp LLC), and the reporting will be in accordance with the Statistical Analyses and Methods in the Published Literature (SAMPL) guidelines. Multivariate data normality distribution will be tested by the Mardia´s coefficients of skewness and kurtosis, and the univariate data normality distribution will be tested by the Shapiro-Wilk test. Overlap among variables will be examined with bivariate Spearman's correlations, and the collinearity by with the variance inflation factor (VIF).

A descriptive analysis of the sociodemographic and psychological variables will be performed. Multilevel linear mixed models of repeated measures will be conducted to assess the effect of the intervention, analyzing the pre- and post-scores of the outcome variables of SCC, MSAS, RFQ-8, and RSE, adjusted with the covariates of age, gender, and other sociodemographic variables. The method of estimation will be the Restricted Maximum Likelihood (REML), which is robust for moderate deviations of normality of continuous outcome variables. The adjustment of the model will be assessed with the Likelihood-Ratio test, the R2, the R2 adjusted, and the Bayesian Information Criteria (BIC). For all analyses, the significance level will be taken as 0.05, the confidence intervals will be calculated, and the effect size (Cohen's d) will be reported.

To achieve the second specific objective, correlations will be calculated between the variables related to the metacognitive abilities assessed with the SCC, MSAS, RFQ-8, RSE instruments, and the self-knowledge measures derived from the RGT. The inclusion of the CORE-OM will make it possible to assess the degree of change achieved with respect to psychological distress. Likewise, the application of CORE-SFB in each session will make it possible to evaluate the suicide risk and percentage of change session by session. With the DASS it will be possible to observe if there have been variations in the levels of anxiety, depression, and stress, although they are not expected to be high at the onset because it is a non-clinical sample.

A secondary analysis will be performed considering LSS as an outcome variable, in order to assess the evolution of a positive result, and its relationship with the other results will also be examined by means of a correlational analysis.

For the exploratory content analysis, two raters will code the constructs collected through the RGT, discuss disagreements found (if any), and perform a descriptive analysis. Inter-rater agreement will be calculated using the Kappa index.

Inclusion Criteria:

• Volunteers between 18 and 29 years of age

Exclusion Criteria:

• Diagnosis of a mental disorder (current or in the last year)
• Current psychological or psychiatric treatment
• Suicidal ideation
• Insufficient level of competence to communicate in Spanish or English

Individual participant data for all primary and secondary outcomes, after deidentification

Data will be available after six months of study completion

Researchers who provide a methodologically sound proposal whose proposed use of the data has been approved by an independent review committee