Kashvi Sethi

The Impact of Psychological Stress on HRV and Neural Activity in Adolescents

Started June 20, 2025

Abstract or project description

Adolescence is a developmental period where intense physiological and psychological development happens, during which the autonomic nervous system and brain mature. According to the World Health Organization (2021), 1 in 7 adolescents (aged 10–19) experiences a mental health disorder globally. But how sudden psychological stress impacts the body — particularly the heart and nervous system in real time — and among children is not well understood. This project is significant because it examines how the brain and heart “talk” to each other during stressful experiences, and how these interactions could be used as an early detectable marker for those at risk for emotional regulation difficulties, stress sensitivity, or even future health risk. During an era when teen mental health has become an increasing concern, knowledge of this circuit could lead to new preventive approaches to physical and emotional health. The two types of psychological stress include acute stress — short-term stress that quickly dissipates (such as studying for a test) — and chronic stress — stress that is long-term and often results from persistent pressure (like family conflict or academic overload). Both types have specific effects on the cardiovascular and nervous systems — acute stress may increase heart rate and awareness while chronic stress may dampen emotional expression, reduce HRV, and heighten the risk of psychiatric and somatic diseases. It is particularly difficult to identify psychological stress in adolescents because symptoms frequently intersect with typical developmental changes. A few physiological markers can also be used for estimating indicators of stress — including cortisol (a stress hormone), blood pressure, galvanic skin response (GSR), HRV, pupil dilation, EEG, fMRI scans, and the most straightforward: heart rate. Being able to understand and wield such tools lets us probe the question of how adolescent bodies and brains respond to stress — and to tease apart where vulnerabilities may or may not lie. This review will explore the neurophysiological basis of Heart Rate Variability (HRV) and its regulation by key brain structures—such as the medial prefrontal cortex (mPFC) and amygdala—that form part of the Central Autonomic Network (CAN). HRV is widely recognized as a noninvasive gold standard for measuring autonomic flexibility and cardiovascular health, particularly in youth, whose regulatory systems are still developing. With the growing accessibility of electroencephalography (EEG), we can now analyze how brainwave patterns shift under pressure, offering insight into neural responses during stress. Together, HRV and EEG provide a unique multidimensional window into the bidirectional communication between the brain and heart. In this project, I will review peer-reviewed scientific literature to understand how acute stress alters both HRV and neural activity in adolescents. More specifically, I will focus on how different types of stressors (e.g., academic pressure or social evaluation) affect the sympathetic and parasympathetic branches of the ANS, and how these shifts appear in HRV metrics and EEG waveforms. This review will lay the groundwork for future project ideas around this topic. For the research component of this project, we will examine the influence of acute psychological stress on the adolescent autonomic nervous system (ANS) and neural activity through HRV and EEG activity. To explore this, participants will take part in a brief, standardized stress-inducing task (for example, a timed math task performed under pressure to obtain good scores) in a safe and controlled setting. HRV data during the task will be captured with the Polar H10 chest strap ECG sensor, and EEG data will be collected through an OpenBCI 8-channel EEG headband before, during, and after the task. These new methods will enable accurate noninvasive monitoring of cardiac and neural dynamics during stress. The experiment will examine these measurements across baseline, stress, and post-stress states to show changes in the balance of autonomic nervous system activity (e.g., decrease in RMSSD or high-frequency HRV) and in cortical activation (e.g., increase in beta wave activity). Integrating these signals, this study plans to investigate the real-time “cross-talk” between the heart and the brain – an increasingly popular area of research known as neurocardiology and relevant in adolescent mental health research. Through its focus on youth physiology, this study has the potential to contribute to the development of early, readily accessible biomarker target metricss for stress sensitivity and emotional regulation difficulties among youth. It may also serve as a basis for future investigations toward pediatric mental health assessment, wearable stress monitoring, and personalized resilience training in teens.