Stress, working memory, and academic performance: a neuroscience perspective

Abstract

The relationship between stress and working memory (WM) is crucial in determining students’ academic performance, but the interaction between these factors is not yet fully understood. WM is a key cognitive function that is important for learning academic skills, such as reading, comprehension, problem-solving, and math. Stress may negatively affect cognition, including WM, via various mechanisms; these include the deleterious effect of glucocorticoids and catecholamines on the structure and function of brain regions that are key for WM, such as the prefrontal cortex and hippocampus. This review explores the mechanisms underlying how stress impacts WM and how it can decrease academic performance. It highlights the importance of implementing effective stress-management strategies to protect WM function and improve academic performance.

Keywords:

• Stress
• cognitive function
  
• working memory (WM)
  
• academic performance
  
• neuroscience
  
• hippocampus
• prefrontal cortex

Introduction

Stress is a part of daily life and can be caused by internal factors, such as thoughts and emotions, as well as external factors, such as illness or trauma. It triggers physiological responses through hormonal and neural processes, enabling individuals to react and adapt to challenging situations. For example, the fight-or-flight response redirects energy resources to vital organs during mental or physical challenges. Although stress can enhance focus and performance in some instances, excessive or chronic stress can decrease physical and psychological well-being, thus reducing academic performance (Juster et al., 2010).

A recent global survey conducted in over 45 countries reported that a growing number of adults classified as Millennials and Generation Z experience stress, anxiety, and worry (Deloitte, 2022). This increase may be attributed to emerging contemporary factors, including the deterioration of sleep hygiene (Irish et al., 2015), the increased use of social networks (Steele et al., 2020), academic stressors, and challenges in peer relationships (Seiffge-Krenke et al., 2013).

Working Memory (WM) is recognized as a robust predictor of academic performance, even surpassing the predictive power of IQ levels (Siquara et al., 2018); stress can negatively impact WM, potentially leading to poor academic performance (Roberts et al., 2011). Acute stress is short-term and typically occurs in response to a specific event, whereas chronic stress is long-term and persists over an extended period. Both types of stress can negatively impact WM function and academic performance.

Understanding the interplay between stress, WM, and academic performance is critical for developing effective stress interventions to improve cognitive function and academic performance. This review explores the concept of WM, the impact of stress on WM, and how these factors collectively influence academic performance from a neuroscience perspective.

Academic performance

Academic performance is an important indicator of the effectiveness of an educational system. Academic performance refers to students’ mastery of course content and skills, their ability to complete academic tasks, and their overall academic achievement. It is linked to individual well-being (Pascoe et al., 2020) and impacts not only current students’ performance at school but also their future career and work opportunities (Mappadang et al., 2022). Poor academic performance is linked to worse social, mental, and physical well-being, along with higher substance use and school dropout rates (Pascoe et al., 2020). Academic performance is typically measured by summative assessments and standardized tests, and the results guide educational policymakers in implementing interventions and development strategies (Stickler & Breland, 2007).

Academic performance and stress

Although moderate stress can enhance learning and increase students’ motivation to learn, excessive stress can impair academic performance (Lewis et al., 2008). Melaku et al. (2015) explored the impact of stress among 329 medical students in different academic years and found that over half (52.4%) of the students experienced stress (Melaku et al., 2015). Greater stress was associated with worse academic performance (Melaku et al., 2015). In a longitudinal study, high school students exposed to chronic stress had lower grades than those infrequently or never exposed to stressors (Schraml et al., 2012). Those with low self-esteem, poor sleep, low social support, high perceived demands, and poor health were more vulnerable to stress (Schraml et al., 2012). The findings of this study support the results of an earlier longitudinal study (Stewart et al., 1999), in which the authors examined the impact of pre-medical school academic performance among 121 medical students surveyed twice, 8 months apart. As anticipated, pre-medical school academic performance predicted academic performance during medical school; however, greater stress was associated with worse academic performance before and during medical school. These studies and growing evidence in the literature support the notion that stress impairs academic performance in students. Understanding the mechanisms involved in how stress impacts academic performance is crucial for developing effective strategies to limit its impact.

Working memory

Executive brain processing refers to high-order neurocognitive processes essential for planning, directing, and monitoring behaviors that facilitate learning and goal achievement (Diamond, 2013). They also govern core cognitive functions, such as WM and inhibitory control (Diamond, 2013). Cognitive factors are important for academic performance, including WM (Siquara et al., 2018). WM is a core cognitive function that involves the ability to cognitively store and actively utilize information over brief periods (Baddeley, 2010). It plays a crucial role in regulating and coordinating the functions needed for decision-making (Baddeley, 2010). According to this definition, WM is an active process that requires memorizing and using acquired information to reach a desired outcome (Aben et al., 2012). A prime example of WM is solving mathematical problems. To solve these types of problems, an individual must hold numbers in their mind while simultaneously applying specific arithmetic laws to find the solutions. WM is strongly correlated with performance in essential academic core skills, including reasoning abilities (Yin et al., 2020). The effectiveness of WM processing is influenced by factors such as emotional state, contextual factors, and specific goals (Blasiman & Was, 2018).

WM is not controlled by a single area in the brain; rather, a diverse neural network, including regions such as the hippocampus (Leszczynski, 2011) and the prefrontal, parietal, and cingulate cortices (Chai et al., 2018), influences it. Different brain circuits are responsible for specific types of memory, such as spatial and object memory. The dorsal system is involved in spatial memory, whereas the ventral system is responsible for object memory (Van Polanen & Davare, 2015). The connectivity between these regions is important for efficient WM processing and allows for the integration of information from different sources. WM engages brain regions such as the frontoparietal brain areas, the dorsolateral prefrontal cortex (DLPFC), and the parietal cortex (Chai et al., 2018). Subcortical regions, such as the midbrain, also play a role in this processing (Chai et al., 2018). In addition to memory-specific areas of the brain, other areas that perform non-memory functions also contribute to WM processing. For example, the cerebellum, which is responsible for regulating motor control, interacts with WM cortical areas (Tomlinson et al., 2014). Similarly, areas responsible for aversive emotions, such as the amygdala, can contribute to differences in WM performance between individuals (Peinado-Manzano, 1990).

The role of WM in academic performance

WM performance is correlated with complex cognitive and learning abilities, such as general intelligence, inhibitory control, language comprehension, reading, and mathematical skills (Bergman Nutley & Söderqvist, 2017). WM assessment is often used to predict academic performance and evaluate children’s educational needs and learning capabilities (Alloway et al., 2009). Likewise, visuospatial and verbal WM are strongly correlated with academic performance (Giofrè et al., 2018).

Both WM and recall—the ability to retrieve information from the past—are required for academic performance in children; however, recall only contributes to passage comprehension and math fluency, whereas WM contributes to passage comprehension, math fluency, reading fluency, and calculation (Blankenship et al., 2015). Therefore, even without recall deficits, WM deficits could affect academic performance, and much of the association between academic underachievement in reading and mathematics is explained by WM deficits (Gathercole et al., 2016). WM impacts multiple processes that affect academic performance, such as encoding, maintenance, and retrieval of information (Nyberg & Eriksson, 2016). Individuals grappling with poor WM function may face challenges in tasks requiring attention, the acquisition of new vocabulary, or problem-solving, which are all essential components of academic performance (Gathercole et al., 2016).

Stress

Physical and psychological stressors that disrupt the body’s normal balance result in a stress response. Stress can manifest as emotional, cognitive, behavioral, or physical symptoms, regardless of the stressor (Attia et al., 2022). Although both acute and chronic stressors can be disruptive, chronic stress is generally more deleterious (Schneiderman et al., 2005). Early-life stressors are major risk factors for comorbidities during development as well as later in life (Shapero et al., 2014).

The body’s response to stress is mediated by two systems: the neural (sympathetic) and the endocrine systems. The sympathetic nervous system produces a rapid and short-lived reaction, triggering the fight-or-flight response by releasing two chemical neurotransmitters: adrenaline and noradrenaline. By contrast, the endocrine system responds slower, but the response lasts longer and is mediated by the hypothalamic–pituitary–adrenal (HPA) axis (McEwen, 2017). The HPA axis is activated by the secretion of corticotropin-releasing hormone (CRH) from the paraventricular nucleus of the hypothalamus, which stimulates the anterior pituitary gland to release adrenocorticotropic hormone. This in turn stimulates the adrenal cortex to produce and release glucocorticoids (McEwen, 2017). After the stressor is removed, a negative feedback mechanism is initiated in which glucocorticoids inhibit further CRH release, ultimately stopping the stress response (McEwen, 2017).

Stress can impact cognitive functions required for academic performance, including WM (Sandi, 2013). Although mild stress can create motivation to learn and improve WM performance (Lewis et al., 2008), excessive stress can cause more harm than benefit. This relationship is complex and depends on the intensity and duration of the stress encountered (Yu, 2023). An “inverted U” relationship has been proposed to describe the impact of stress on cognitive function: mild stress may be beneficial compared with no stress, but beyond an optimum level, memory begins to decline (Diamond et al., 1992).

The neuropsychological mechanisms of the impact of stress on WM

Stress can disrupt WM function in various ways. Stress impairs synaptic plasticity and affects the learning and memory processes (J. J. Kim et al., 2006). The hippocampus, a vital brain region for memory and learning, is especially sensitive to stress-induced damage (J. J. Kim et al., 2006). A recent study by Shields et al. (2019) explored the effect of stress on WM capacity versus its effect on WM precision. They found that stress impairs WM by reducing WM capacity, but it spares WM precision (Shields et al., 2019). Furthermore, consistent with cognitive models of mood disorders, stress can lead to an increase in non-task-related negative thoughts, such as worry (Ellis, 1990). In their meta-analysis, Zetsche et al. confirmed that rumination (i.e. repetitive negative thinking) is associated with deficits in discarding irrelevant information from WM (Zetsche et al., 2018). A review by Buschman (2021) discussed two types of thought interferences that negatively impact WM. One type occurs when interference arises from overlapping representations, which happens when two or more items overlap in WM. This type of interference impedes the ability to accurately decode information about individual items (Buschman, 2021). The second type of interference, which the author labeled competitive interference, occurs when the increased number of items required for WM processing leads to increased interference between their representations within the neural population of WM. Therefore, the accuracy of the first item presented decreases (Buschman, 2021). Another alternative mechanism underlying the impairment of WM under stress is the destructive effect of stress on sleep. Stress induces dysregulation in the sleep–wakefulness cycle, making it difficult to fall asleep and/or stay asleep (Kalmbach et al., 2018). WM performance is impaired under sleep deprivation (Xie et al., 2019) possibly through the selective impairment of emotional WM (Gerhardsson et al., 2019). Sleep deprivation is associated with altered neural activity, specifically in the parietal and frontal areas of the brain, which are key regions involved in WM (Frenda & Fenn, 2016).

Lastly, stress can impair individuals’ ability to update affective information in their WM, particularly positive information (Luethi et al., 2008). This can be a form of maladaptive affective processing, as stressed individuals may experience a mental struggle in accommodating such information. This was also demonstrated in the context of depression in a study by Levens and Gotlib (2010). They compared 29 individuals with major depressive disorders with 29 controls performing a 2-back task, during which the participants were simultaneously presented with a sequence of neutral, sad, or happy faces. Individuals with depression were not only slower to disassociate from sad faces but also faster to disassociate from happy facial stimuli (Levens & Gotlib, 2010). A study by Hood et al. (2015) found that anxiety mediated the negative effect of acute stress on WM but only in participants who demonstrated high cortisol levels after acute stress exposure (Hood et al., 2015). A previous study investigating emotional WM capacity in a cohort of individuals with post-traumatic stress disorder (PTSD) found that participants were less likely to perform well on WM tasks when presented with trauma-related thoughts compared with neutral ones (Schweizer & Dalgleish, 2011). The authors concluded that such participants are unable to use WM effectively when presented with negative thoughts and suggested WMT as a potential method of improving WM capacity in these patients (Schweizer & Dalgleish, 2011).

The distinctive mechanisms of acute and chronic stress on WM

Acute and chronic stress affect WM via different mechanisms. Acute stress can create an attentional bias toward stress-related stimuli, diverting cognitive resources from required tasks (Jiang et al., 2017), whereas chronic stress can reduce the updating process in WM, impairing cognitive flexibility and the ability to adapt to new challenges (Yuan et al., 2016).

The mechanisms and effects of acute stress on working memory

Acute stress affects WM mainly through a binary mechanism that involves the release of glucocorticoids and the activation of neural pathways (Barsegyan et al., 2010). Acute stress rapidly activates the autonomic sympathetic system, leading to the release of catecholamines (Barsegyan et al., 2010). The impact of acute stress on WM performance may vary depending on the timing of the release of these two chemical mediators. Studies suggest that in shorter time frames following stress (10 min), noradrenaline tends to predominate in mediating the physiological response, whereas at later times (25 min post-stress event), a hormonal-based response mediated by glucocorticoids predominates (Geißler et al., 2023). Supporting this finding, Qin et al. conducted a functional magnetic resonance imaging (fMRI) study involving 27 healthy participants who performed a WM task under induced experimental acute stress; they also monitored the participants’ autonomic and endocrine responses. The authors documented reduced activation of DLPFC activity, which was coupled with increased sympathetic HPA axis activity (Qin et al., 2009).

Stress signaling pathways negatively affect the structure and function of the prefrontal cortex (PFC), a key region in WM. Electrophysiological studies have demonstrated a direct link between reduced background theta activity in the PFC with reduced WM function under acute stress induction; this further supports the determinant role of PFC in WM impairment under stress (Gärtner et al., 2014). Additionally, as mentioned above, specific brain regions such as the DLPFC are susceptible to acute stress (Qin et al., 2009).

Studies on acute stress in humans disagree on the direction and magnitude of the effects on WM. Whereas some studies have reported a negative impact (Gärtner et al., 2014; Xin et al., 2020; Zandara et al., 2016); others have found no effect or a positive effect (Hood et al., 2015). This variability in the studies can be attributed to several factors that contribute to stress outcomes (Diamond et al., 1992). Various factors have been identified that influence the effects of acute stress on WM, such as uncertainty and past stress experiences (De Berker et al., 2016; Luettgau et al., 2018). Specifically, emotions play a pivotal role in modulating the effect of acute stress on WM performance, with anxiety levels mediating the negative influence of stress on WM, particularly in individuals with elevated cortisol levels (Hood et al., 2015).

Glucocorticoids operate through abundant receptors in the brain, specifically in regions key to WM, such as the PFC, hippocampus, and amygdala (Koning et al., 2019). Although glucocorticoids contribute to the potential deficit in WM, they are not sufficient to mediate all the effects of acute physiological stress (Shields et al., 2016). Furthermore, acute stress alters PFC neural connections, including the release of high levels of catecholamines in the PFC, contributing to the impairment of WM (Arnsten, 2009). Interestingly, stress-induced WM deficits can be prevented by transcranial stimulation of the DLPFC, opening the possibility of using transcranial stimulation in clinical contexts (Bogdanov & Schwabe, 2016).

In summary, acute stress can impair WM performance through stress triggering the release of glucocorticoids (GCs) and catecholamines, which both work to modulate stress-sensitive brain areas that are crucial for WM performance. This relationship is further modulated by many contextual and endogenous factors that influence the extent and direction of stress’ impact on working memory performance.

The mechanism and effects of chronic stress on working memory

Chronic stress causes hormonal signaling and neurotoxic changes within the hippocampus (E. J. Kim & Kim, 2023) and impacts PFC-dependent behaviors, such as WM performance (Matuszewich et al., 2014). In addition, chronic stress can lead to structural alterations and reduced brain volume in cognitive areas that are key for memory, such as the hippocampus (Lupien et al., 2018). Collectively, these changes can have lasting effects on cognitive function and potentially accelerate cognitive decline later in life (Christensen et al., 2023).

Chronic exposure to stressful events in life can have a negative impact on WM capacity because of the competition between cognitive and attentional resources in WM tasks and stress-induced feelings, thoughts, and behaviors (Klein & Boals, 2001). This competition limits WM capacity and is particularly pronounced in challenging WM tasks. For example, individuals with PTSD, which is due to chronic stress, were less able to remember words within trauma-related sentences than individuals with a history of trauma but no PTSD (Schweizer & Dalgleish, 2011). The authors suggested that WM capacity was interrupted in emotionally threatening contexts, such as traumatic past experiences, in this group (Schweizer & Dalgleish, 2011). Individuals with post-traumatic stress symptoms can have difficulty regulating behaviors and emotions, which is reflected in poor academic performance (Mathews et al., 2009). Chronic physiological stress resulting from childhood poverty has also been associated with poor WM function in adulthood (Evans & Schamberg, 2009). Those with childhood trauma are more prone to academic failure, and this is mediated by psychological health disorders (Larson et al., 2017)

The ability to maintain information in WM relies on the intricate interplay between the hippocampus and PFC as well as other areas, such as the amygdala (Lupien et al., 2007). Animal and human studies have shown that chronic stress can significantly impact these regions through neuronal and hormonal mechanisms (McEwen, 2017). In areas such as the hippocampus, which has a high density of glucocorticoid receptors, chronic stress can lead to functional and morphological changes in the brain that cause apoptotic alterations (McEwen, 2017).

Animal studies have also demonstrated that chronic stress can alter neuronal structure and interrupt neural communication in areas crucial for WM, such as the PFC (Radley et al., 2006), and alter the release of neurotransmitters such as dopamine (Mizoguchi et al., 2000). An fMRI study involving healthy adults found disrupted functional connectivity in the PFC networks after only 1 month of exposure to psychosocial stress (Liston et al., 2009). These effects were reversible after the cessation of stressful stimuli (Liston et al., 2009). Although this study did not directly measure WM, it did measure attentional control, which is a critical component of WM and is likely mediated by the same neural substrates (Morey et al., 2011).

In summary, chronic stress can impair WM performance through structural brain alterations, neurochemical changes, and disruptions in the neural circuitry. These effects can manifest as difficulties in concentration, problem-solving, and information retention, posing considerable challenges to optimal WM function. Protective factors against WM deficits under chronic stress conditions include higher self-awareness that allows individuals to direct attentional resources toward WM tasks (Xing et al., 2022), along with strong self-regulation in children, which protects them from the disruptive effects of physiological stress on WM later in life (Evans & Fuller-Rowell, 2013).

Conclusion and directions for further research

Stress can impede academic performance by affecting WM and other cognitive processes as well as causing demotivation, low self-esteem, and weak coping skills in students. WM influences various cognitive and learning abilities and is a determining factor for academic performance. Although education-dependent settings may shape the impact of stress on WM, these factors have not been fully explored yet. WM performance is governed by an attention control system with a limited capacity, and stress can redirect attention and neuronal resources away from learned information. Acute stress influences WM capacity via noradrenaline and glucocorticoid release, and the effects vary depending on gender, emotional valence, and other individual factors. Chronic stress leads to deleterious structural and functional changes through the disturbance of the PFC and hippocampus. These changes reduce the WM resources available for academic tasks. These findings have significant implications for educators, policymakers, and institutions.

Stress can be harnessed for the benefit of students (i.e. “good stress”); to a certain extent, stress can mobilize neural resources required to achieve a goal, suggesting that adopting a more positive perspective on stress could support students on their academic journey (Rudland et al., 2020). However, when students experience excessive stress, their cognitive load becomes overwhelming, hindering effective learning. Researchers have developed several strategies to alleviate cognitive load in learning environments (Paas & Van Merriënboer, 2020). This is an interesting area for further exploration that could have significant implications for real-world applications.

It is worth noting that children in the early stages of development are more susceptible to developing WM defects when exposed to stress at a young age (Evans & Schamberg, 2009). Implementing strategies to manage and alleviate stress among students, especially in the early stages of their education, may improve their academic outcomes (Hsu & Goldsmith, 2021). However, devising effective stress relief and management strategies in the academic environment is challenging because of varying backgrounds, individual histories, and biological differences that impact how stress affects academic performance. Furthermore, instructional techniques, such as retrieval practice, have been developed to improve WM capacity, which may help mitigate the impact of stress-related decreases in WM (Bertilsson et al., 2021). This is a critical topic and underscores the need for additional research in this area. Training WM induces changes in brain connectivity, specifically in the frontal and parietal cortices, along with dopamine receptor activity, which is promising for improving neural plasticity and learning (Klingberg, 2010). Because the neural circuitry of WM varies from person to person, the development of universally successful WM training treatments is challenging; however, studies are ongoing (Sala & Gobet, 2020). Xiu et al. (2018) and Sari et al. (2020) have also explored WM training as a means of regulating stress-related emotions, such as anxiety and attention control, yielding promising results (Sari et al., 2020; Xiu et al., 2018). Although not all WM training is generalizable to other domains, WM provides important benefits in certain domains (Klingberg, 2010). These findings highlight the importance of further research and therapeutic exploration in this area. Moreover, future studies on different types of WM training may uncover the potential to drive transfer effects (Pappa et al., 2020). Studies have also explored other therapeutic interventions to reduce stress or improve WM, such as mindfulness practices (Li et al., 2021), meditation (Suwit Uopasai, 2022), and relaxing exercises (Hubbard & Blyler, 2016). For example, progressive muscle relaxation training improved WM and academic performance among 128 graduate students. The treatment group showed favorable anxiety scores and higher academic achievement compared with the control group (Hubbard & Blyler, 2016).

In summary, stress and WM are interconnected through acute and chronic neurological processes, including hormone release, functional and structural brain changes, and impacts on academic performance. Understanding this relationship is crucial for optimizing learning outcomes and supporting students to reach their academic potential. A deeper and more comprehensive understanding of how stress affects WM will inform monitoring, prevention, and intervention strategies for students. Effective stress-management strategies are crucial to protect WM capacity and enhance academic success.

Disclosure statement

The authors have no competing interests to declare.

Data availability statement

Data sharing is not applicable to this article because no new data were created or analyzed in this study.

Notes on Contributor

Dr Abeer F. Almarzouki, MBBS, PhD, Department of Clinical Physiology, Division of Neuroscience, Faculty of Medicine King Abdulaziz University.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.