Study: chronic stress reshaped alpha-band brain activity, and a month of cognitive training improved visual memory in frontline students
- A Perceived Stress Scale (PSS-10) survey of 1,200 frontline-zone students found 62% with moderate stress, 22% with low stress, and 16% with high stress; 160 students aged 18–24 with low or moderate stress (40 women + 40 men per stress level) entered the main study.[1]
- After one month of CogniFit training, the share of correctly completed visual memory tasks rose in every group, e.g. from 76.06% to 89.4% in low-stress men (P = 5.07 × 10⁻¹⁷) and from 78.20% to 93.05% in low-stress women (P = 1.67 × 10⁻¹⁴), about 17–19% across the sample.[1]
- Perceived stress reshaped where alpha activity mattered: in low-stress men, frontal alpha at the right prefrontal site Fp2 explained 43% of the variation in performance at the first test (β = 18.59; R² = 0.43), while women showed more balanced bilateral prefrontal activity.[1]
- What it does not show: a single-center observational study of young Ukrainian frontline students with no untrained control group, so it cannot prove training, rather than practice or natural change, caused the gains, and should not be generalized.
Chronic stress disrupts the brain's balance of excitation and inhibition, particularly the rhythmic activity of neural networks in the alpha frequency range (8–12 Hz). A regulated alpha rhythm is closely tied to working memory, attention and executive control, and prolonged stress is known to suppress alpha power, a pattern associated, in prior work, with poorer concentration and memory.
A 2025 study in Regulatory Mechanisms in Biosystems examined this relationship where chronic stress is concentrated: young people living near a military front line in Ukraine. The authors measured resting-state EEG alpha-band power spectral density (PSD) and visual memory before and after a month of cognitive training, asking how perceived stress changed the link between brain activity and memory, and whether digital training could improve performance in stressed students.
What the study tested
The study was conducted at Oles Honchar Dnipro National University and approved by its Bioethics Commission (protocol No. 1, 17 October 2023). In a first screening, 1,200 students completed the Perceived Stress Scale (PSS-10): 62% had a moderate level of stress, 22% a low level, and 16% a high level (Fig. 1).[1]
For the main study, 160 students aged 18–24 were divided by sex and stress level into four groups of 40 each (men and women, low or moderate perceived stress). Eligible participants had stable physical and mental health, slept at least 7 hours in the last 5 days, scored at or above average on the CogniFit Memory Test, and were right-handed with normal or corrected vision. Women were tested in the follicular phase (days 5–10) to reduce hormonal influences.
EEG and intervention. Resting bioelectrical activity was recorded with the Neurocom complex (KHAI Medyka, Ukraine) using silver-chloride electrodes per the 10–20% system (resistance ≤5 kOhm, 500 Hz), at rest and again after one month, in 10-second epochs. Participants trained on the CogniFit platform; short-term visual memory was evaluated with the platform's WOM-REST Recognition Test, memorizing visual stimuli then identifying them among distractors. The primary outcome was the percentage of correctly completed tasks, compared before and after training with a one-way ANOVA (α = 0.05), and regression relating alpha-band PSD at each EEG lead to performance.[1]
What it found, visual memory after training
Cognitive training was associated with a statistically significant improvement in visual memory performance in every group, clearest in low-stress students, but significant in moderately stressed participants too.
| Group | Before training | After training | ANOVA | P-value |
|---|---|---|---|---|
| Men · low stress | 76.06% (SD 3.15)[1] | 89.4% (SD 4)[1] | F1,78 = 260.67[1] | 5.07 × 10⁻¹⁷ |
| Women · low stress | 78.20% (SD 2.00)[1] | 93.05% (SD 5.98)[1] | F1,39 = 107.41[1] | 1.67 × 10⁻¹⁴ |
| Men · moderate stress | 67.47% (SD 8.16)[1] | 81.72% (SD 8.64)[1] | F1,79 = 42.19[1] | 8.10 × 10⁻¹¹ |
| Women · moderate stress | 75.13% (SD 13.95)[1] | 83.88% (SD 6.83)[1] | F1,38 = 12.95[1] | 7.61 × 10⁻⁴ |
Across the four groups, both sexes improved visual short-term memory by approximately 17–19%, consistent, the authors note, with the working-memory-training literature. Low-stress participants reached the highest post-training scores; moderately stressed participants improved but showed more instability in their neural patterns, indicating stress-related barriers to neuroplastic adaptation.[1]
How stress reshaped the alpha band
Regression related alpha-band PSD at each EEG lead to performance. At the first test, frontal alpha in low-stress men was positively associated with better performance: at the left prefrontal site Fp1, β = 14.62 (95% CI 5.46–23.78), R² = 0.22, and at the right prefrontal site Fp2, β = 18.59 (95% CI 11.53–25.64), R² = 0.43, right-prefrontal alpha explained 42.8% of the variation in correct responses. In posterior (parietal-occipital) regions the relationship was inverse.[1]
The pattern differed by stress and sex. Low-stress men showed dominant right-frontal activation (Fp2), suggesting hemispheric specialization, while women showed more balanced bilateral prefrontal activity. In moderately stressed participants the associations were weaker, read as reduced neural efficiency under stress.
After a month of training, both groups showed increased frontal alpha and decreased parietal-occipital alpha, a shift the authors interpret as process automatization, with cognitive control becoming increasingly frontally mediated. In low-stress men after training, Fp2 reached R² = 0.963.[1]
Limitations, what this does NOT show
No untrained control group in the main analysis. Performance was compared within each group before and after training, not against a group that did not train, so practice effects and natural change over the month cannot be fully separated from a training effect.
Narrow population. Participants were healthy, right-handed Ukrainian students aged 18–24 living near a military front line, pre-screened for stable health and average-or-better baseline cognition. Findings should not be generalized to older adults, clinical populations, or people with high stress (the high-stress screening cohort was not analyzed).
Single platform task. Short-term visual memory was measured with one recognition test, EEG was resting-state rather than task-locked, and the study did not test whether gains persisted or transferred to everyday function. The authors emphasize that training effectiveness "depends on how well people handle stress and how their brains are structured."
Where this fits in the broader evidence
The findings sit alongside a small but growing line of work on training the stressed brain. A 2024 study by Loock and Schwabe reported that six weeks of intensive adaptive memory training left healthy adults' working memory resilient to acute stress; earlier neurofeedback work (Zoefel et al., 2011) showed that increasing alpha-component activity could improve spatial memory. This 2025 study extended that direction to chronically stressed students. See the research index, and related pages on cognition in adults over 60 and brain training for older adults.
References
- Impact of chronic stress on alpha band spectral power and the potential of digital correction of cognitive functions. Regulatory Mechanisms in Biosystems 2025, 16(3), e25099. doi:10.15421/0225099 The study covered on this page.
- A global measure of perceived stress. Journal of Health and Social Behavior 1983, 24(4), 385–396. doi:10.2307/2136404
- Cognitive training prevents stress-induced working memory deficits. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging 2024, 9(10), 1039–1047. doi:10.1016/j.bpsc.2024.05.005
- The neural correlates of psychosocial stress: A systematic review and meta-analysis of spectral analysis EEG studies. Neurobiology of Stress 2022, 18, 100452. doi:10.1016/j.ynstr.2022.100452
- Stress-related deficits of older adults' spatial working memory: An EEG investigation of occipital alpha and frontal-midline theta activities. Neurobiology of Aging 2018, 69, 239–248. doi:10.1016/j.neurobiolaging.2018.05.027
- Neurofeedback training of the upper alpha frequency band in EEG improves cognitive performance. NeuroImage 2011, 54(2), 1427–1431. doi:10.1016/j.neuroimage.2010.08.078