Mindfulness Intervention Affects Cognitive Abilities of Students: A Time–Frequency Analysis Using EEG

The instantaneous frequency measurement is the primary focus of different variably-dimensions signal processing applications. It addresses the non-stationarity of signals globally and the spread of signal frequency locally across time. The present work evaluates the effect of a mindfulness intervention on cognitive workload through different frequency step sizes utilizing one dimensional Gabor function and discrete wavelet transform (DWT) on Electroencephalogram (EEG) signals. Time–frequency tiling is carried out for four different cognitive workload levels of a visual task which shows variation in frequencies along the timeline. The statistical analysis utilizes the mean of small segments (100 ms) from long-duration (7 s) EEG data. The significant difference is found in post-meditation data than pre-meditation data for 90% subjects (18 Subjects out of 20) using a paired t-test with p-value < 0.001 for frontal and occipital electrodes from left and right hemisphere. The right hemisphere shows higher modulation of α activity than the left hemisphere. The results using the Gabor function show good performance by meeting the generalized uncertainty principle. The results with DWT show ‘what is where’ on time as well as frequency scales clearly with orthogonal basis. Moreover, the cognitive load of four levels is discriminable for an individual with pre-meditation data of twenty subjects, which is clarified with behavioral measures and using statistical analysis on objective measures (p-value < 0.05). The empirical evidence based on EEG signal analysis clarifies that the proposed method is used as an initialization step to quantify cognitive workload based on its emergent frequency at a given time scale for developmental research. This initial investigation holds relevance in determining the optimal duration for implementing meditative programs among students.