短视频作为移动互联网时代的一种新兴媒介，近年来在青少年群体中快速兴起、影响深远。短视频使用满足了青少年娱乐、社交与寻求认同等方面的发展需要，也为青少年文化注入新的活力。但与此同时，其对青少年认知发展与学习的潜在负面影响也引发了人们的关注与担忧。然而，已有研究对这一问题的探讨仍停留在理论假设层面，涉及媒介使用行为与用户认知功能及学业表现的实证研究大多集中在成人网络、手机与社交媒介使用，缺乏针对青少年短视频使用的证据。因此，本研究致力于探究青少年短视频使用行为与认知功能及学业表现间的关系。为探究这一问题，本文采用行为与神经生理数据相结合进行定量分析的方法开展研究。首先依据短视频及短视频应用的媒介性质与用户行为特征将青少年短视频使用行为主要聚焦到日均使用量和算法依赖程度两个方面，并对青少年短视频的使用现状进行较为全面、深入的刻画。其次，对使用行为分别与学业延迟满足、工作记忆、言语能力及学业表现进行回归分析以探究短视频使用的潜在影响，并运用结构方程模型分析认知功能在使用行为与学业表现间的中介作用。在此基础上，以发展的视角进一步探究不同年龄段青少年受短视频使用潜在影响的年龄差异。此外，本研究还通过收集并分析青少年静息态脑电信号与短视频使用行为间的关系，从认知神经科学的视角印证短视频使用对青少年认知功能的潜在影响。本研究的主要发现包括：（1）青少年短视频日均使用量、算法依赖程度与成瘾倾向之间呈显著正相关。（2）短视频日均使用量能够预测两个年龄段青少年更低的学业延迟满足倾向与学业表现，同时预测12-13岁群体更差的工作记忆与言语能力。算法依赖程度能够预测该群体更低的工作记忆任务表现。学业与非学业目的使用对以上效应未造成显著差异。（3）12-13岁群体短视频日均使用量及算法依赖程度通过负向预测工作记忆进而对学业表现施加潜在负面影响。言语能力仅在日均使用量与学业表现的负相关关系中起到中介作用。（4）总体上，青少年早期相比后期更易受到短视频使用行为对认知功能及学业表现的潜在负面影响。（5）静息态脑电delta、theta、alpha、beta和gamma能量分别与特定的青少年短视频使用行为有关，能在一定程度上印证高使用量与高算法依赖对青少年延迟满足、工作记忆与言语能力的潜在影响。研究结果将对指导青少年合理使用短视频、对教育者反思短视频对青少年身心健康发展的影响产生借鉴意义。
As a newly-rising media giant, short videos have rapidly gained popularity among adolescents and exerted its far-reaching influences. Despite its unique affordances for satisfying adolescent’s developmental needs for entertainment, social interaction and identity-seeking as well as empowering youth culture, there is rising concern over its potential impact on adolescent users’ cognitive and learning performance. However, this issue is still raised as a hypothesis due to a lack of empirical evidence on adolescents’ SVA use, though quite a few studies have been conducted on adult users of the Internet, social media and smartphone. Thus, this study is intended to examine the relationship among adolescents’ user behaviors regarding SVA, their cognitive functioning and academic performance. In order to explore this key issue, this study adopts both behavioral and neurophysiological data for quantitative analysis. First, based on the characteristics of SVAs and user behaviors, this study is mainly focused on two aspects of SVA user behaviors, including daily usage and reliance on algorithmic recommendations, and attempts to describe the status quo of how adolescents use SVAs. Second, regression analysis is used to find out whether adolescents’ cognitive functioning, including academic delay of gratification, working memory and verbal ability, as well as academic performance, can be predicted by SVA user behaviors. The mediating roles of cognitive functioning between SVA user behaviors and academic performance are also testified using structural equation modelling. Third, taking a developmental perspective, this study further examines the age-related difference between early and late adolescence regarding the potential impact of SVA use. Additionally, the study measures resting-state brain activity using EEG in order to supplement the results drawn from behavioral data and offer new perspectives on the interpretation of SVA use effects.The main findings of this research are displayed as follows: (1) There exist positive correlations among SVA daily usage, dependency on algorithmic recommender and SVA addiction. (2) Daily usage of SVA predicts lower ADOG and academic performance for both age cohorts. For the younger cohort only, SVA daily usage predicts lower working memory and verbal ability, and the dependency on algorithmic personalization predicts lower working memory. The purpose of SVA use, i.e., academic and non-academic purpose, makes no difference regarding these effects. (3) Younger adolescents’ working memory capacity and verbal ability simultaneously mediate the associations between their SVA daily usage and poorer academic performance. Their working memory capacity also mediates the negative relationship between reliance on algorithmic recommender and academic performance. (4) Generally, younger adolescents show higher susceptibility of to SVA use compared to their older counterparts. (5) Correlations between adolescents’ resting-state brain activity, including delta, theta, alpha, beta and gamma band power, and SVA user behaviors can provide supplementary evidence and interpretation on the potential impact of SVA use on cognitive development. These findings can provide insights on how to instruct adolescents for reasonable use of SVAs and on how parents and educational practitioners should reflect on the relationship between SVA use and the healthy development of adolescents.
