Correlating Visual and Auditory Perception and Attention Level Using EEG Parameters

Focus, alertness level, and reaction time are key cognitive factors and are dependent on visual and auditory perception. Present work aims to study the functional changes in cortical regions; through frequency domain features of EEG, in correlation to perception and attention level (visual and auditory), using a computer screen-control task. Psychophysiological data consisting nine channel EEG for 26 subjects were recorded during three conditions; 5 minutes eyes closed (EC), 5 minutes visual focus on a red dot on dark screen (DOT), and approximately 10 minutes battery test consisting 3 visual and 3 auditory subsections (intrinsic, cross-modal phasic and unimodal phasic) through perception and attention functions: alertness (WAFA). Relative power spectrum density (PSD) of different activity bands for each epoch of one second have been computed; corresponding to each task. For WAFA task, mean reaction time (MRT, in milliseconds) and dispersion of reaction time (DRT, in milliseconds) have been registered. Correlation values between PSD of every EC, DOT and WAFA; and, MRT and DRT of WAFA assignment was registered. For task EC, correlation values are positive for theta, alpha, negative and positive for MRT and DRT consecutively, throughout the cortical region. For task DOT, correlation values negative for delta, theta and gamma; positive for alpha and beta. For task WAFA, correlation values are negative for delta and theta, but for different subsections of visual and auditory (intrinsic, cross-modal phasic and unimodal phasic) are either of positive, negative or uncorrelated for alpha, beta and gamma throughout the cortical region. EEG band activities are observed to be directionally correlated with visual and auditory alertness level.