The extraction of semantic features from EEG signals presents a novel approach to understanding the neural mechanisms underlying perception, imagination, and vividness. This study examines the correlation between EEG-based brain activity and subjective imagery ratings derived from the Vividness of Visual Imagery Questionnaire (VVIQ) and the Bucknell Auditory Imagery Scale (BAIS-V). We used a dataset containing recordings of 15 subjects subjected to audio, pictorial and orthographic stimuli. Before proceeding with feature extraction, the signal was appropriately preprocessed. As regards feature extraction, Power Spectral Density (PSD) and frequency bands were used. In this way we ensure that the neural representations that we consider are significant.