Task-Related EEG Spectral Power (Theta and Beta Bands) During Visual Memory Performance Under Different Levels of Perceived Stress

Dataset Overview This dataset contains task-related EEG spectral power density (PSD) values in the theta (4-8 Hz) and beta (13-30 Hz) frequency bands recorded during performance of a visual memory task. The dataset also includes: Visual memory accuracy (% correct responses) Perceived Stress Scale total score (PSS-10) Participant sex The dataset was used to examine associations between oscillatory brain activity and cognitive performance under varying levels of perceived stress. Participants The study included university students aged 18-24 years from Oles Honchar Dnipro National University (Ukraine). All participants: Provided written informed consent Were informed about study procedures and potential risks Participated voluntarily Inclusion criteria Participants met the following criteria: Stable physical and mental health No history of neurological, psychiatric, or cognitive disorders Normal cognitive functioning (Mini-Mental State Examination) Memory and attention not below normative mean (CogniFit Memory Test) Moderate to high emotional resilience (Connor-Davidson Resilience Scale) High positive affect and low negative affect (PANAS) Average sleep duration ≥ 7 hours during the 5 days preceding the experiment Right-handed (standard handedness inventory) Normal or corrected-to-normal vision Stress Stratification Participants were selected from a larger screening cohort of 1.200 students residing in frontline territories of Ukraine who completed the Perceived Stress Scale (PSS-10). From this cohort, 160 participants (80 males, 80 females) with low or moderate perceived stress were selected. Sample size was determined using a priori power analysis (G*Power; α = 0.05; power = 0.80), indicating adequate power to detect medium-sized effects. Ethical Approval The study was approved by the Bioethical Commission of Oles Honchar Dnipro National UniversityProtocol No. 1, October 17, 2023. The study was conducted in accordance with: Declaration of Helsinki (1964, revised 2013) Convention on Human Rights and Biomedicine Experimental Design The full experimental protocol included: 1. Resting-state EEG (eyes closed, 1 min) 2. Resting-state EEG (eyes open, 1 min) 3. Task-related EEG during visual memory performance ⚠️ The present dataset contains task-related EEG data only. Resting-state recordings are not included here. Cognitive Task Visual short-term memory was assessed using the WOM-REST Recognition Test (CogniFit platform, USA). Task structure: Encoding phase (1.5-2 minutes) Recognition phase (4-5 minutes) Total task duration: approximately 5-7 minutes (varied depending on response speed). EEG Recording EEG was recorded using the Neurocom system (KhAI Medika, Ukraine). Recording conditions: Sound-attenuated, electrically shielded chamber Silver/silver chloride electrodes International 10-20 system Sampling rate: 500 Hz Impedance maintained below 5 kΩ Reference montage: (specify here — e.g., average reference / linked mastoids) Signal Processing EEG preprocessing included: Band-pass filtering Automated artifact rejection (Neurocom integrated algorithms) Visual inspection by an experienced experimenter Exclusion of segments with ocular or muscle artifacts Exclusion of motor response periods Spectral power density (PSD) was computed using: Welch’s method 2-second Hamming windows 50% overlap No baseline normalization Frequency bands: Theta: 4-8 Hz Beta: 13-30 Hz PSD values represent averaged power across artifact-free task epochs. Units: µV²/Hz No connectivity, phase-synchronization, or cross-frequency coupling measures were computed. Electrodes Included F3, F4, FzC3, C4, CzP3, P4, PzO1, O2, Oz These sites correspond to frontal, central, parietal, and occipital cortical regions associated with working memory and visuospatial processing networks. Behavioral Measures Visual memory accuracy (% correct responses) PSS-10 total score File Structure Each row corresponds to one participant. Variables: Participant_ID Sex (Male/Female) PSS_score Accuracy_percent PSD_Theta_[Electrode] PSD_Beta_[Electrode] Example: PSD_Theta_F3PSD_Beta_F3PSD_Theta_P4PSD_Beta_P4etc. Randomization and Bias Control Stratified randomization by sex and stress level Computer-generated allocation A blinded independent researcher analyzed EEG and behavioral data Statistical Analysis Statistical analyses were performed using RStudio (version 2023.12.1). Linear regression models examined associations between PSD (theta and beta bands) and task accuracy. Assumptions tested: Linearity (residual plots, Ramsey RESET) Normality (Shapiro-Wilk) Homoscedasticity (Breusch-Pagan) Influential observations (Cook’s distance, leverage) Two-tailed tests; α = 0.05.Bonferroni correction applied within each stress-by-sex subgroup. Notes on Interpretation The dataset includes only spectral power measures. No network-level metrics are provided. Cross-sectional design: causal inference is not supported. Results reflect oscillatory activity during task performance, not resting-state dynamics. Keywords: electroencephalography (EEG); chronic stress, frontline population, gender, spectral power density (PSD); visual memory.