EEG-based investigation of the impact of room size and window placement on cognitive performance

Abstract

This study investigated changes in scalp electroencephalography (EEG) features associated with short-term exposure to four virtual classroom designs, with different window placement and room dimensions. Participants engaged in five cognitive tests in each design condition: the Stroop Test, the Digit Span Test, the Benton Test, a Visual Memory Test, and an Arithmetic Test. Performance on the cognitive tests and EEG data were analyzed by contrasting various classroom design conditions. The cognitive test performance results showed no significant differences related to the design changes in the room studied. We computed frequency band-power and connectivity EEG features to identify changes in neural patterns associated to the different design conditions. A leave-one-out machine-learning classification scheme was implemented to assess the robustness of the EEG features, with the classification accuracy evaluation of the trained model iteratively performed against an unseen participant’s data for the test set. The feature selection and classification results located consistent differences in the EEG features that held predictive power (p<0.003) across participants in the different classroom design conditions: a. Neural vs One-Window, b. Neutral vs Two-Windows, c. Neutral vs Wide room. This effect was observed for the tasks that required short-term memory encoding, including the Digit Span Test (median test set classification accuracy: a. 53.8%, b. 51.3%), the Benton Test (a. 61.3%, b. 56.3%), and the Visual Memory Test (a. 55.0%, b. 57.5%, c. 61.3%). The most discriminative EEG features were primarily frequency band-power features, observed in bilateral occipital, parietal, and frontal regions in the theta (4-8 Hz) and alpha (8-12 Hz) frequency bands. The connectivity features reinforced these findings by showing that there were changes in the transfer of information from centro-parietal to frontal electrodes in the different classroom conditions. This study provides rigorous evidence that brain activity features during cognitive tasks are affected by the design elements of window placement and room dimensions in a virtual classroom. The ongoing development of this EEG-based approach has the potential to strengthen evidence-based design through evaluation of robust neurophysiological evidence.