International Journal of Engineering and Technology

Cognition is a group of information processing activities that involves the visual attention, visual awareness, problem solving and decision making. Finding the cognitive task related regional cerebral activations are of great interest among researchers in cognitive neuroscience. In this study four different types of cognitive tasks, namely tracking pendulum movement and counting, red flash counting, sequential subtraction, spot the difference is performed by 32 subjects and the EEG signals are acquired by using 24 channels RMS EEG-32 Super Spec machine. The analyses of the EEG signal are done by using well known spectral methods. The band powers are calculated in the frequency domain by using the Welch method. The task- relaxes relative band power values and the ratios of theta band power/ beta band power are the two variables used to find the regional cerebral activations during the four different cognitive tasks. The statistical paired t test is used to evaluate the significant difference between the particular tasks related cerebral activations and relaxation. The statistical significance level is set at p< 0.05. During the tracking pendulum movement and counting task, the cerebral activations are found to be bilateral prefrontal, frontal, right central and temporal regions. Red flash counting task has activations in bilateral prefrontal, frontal, right central, right parietal and right occipital lobes. Bilateral prefrontal regions are activated during the sequence subtraction task. The spot the difference task has activations in the left and right prefrontal cortex. The unique and common activations regions for the selected four different cognitive tasks are found to be left and right prefrontal cortex. The pre frontal lobe electrodes namely Fp1 & Fp2 can be used as the recording electrodes for detailed cognitive task analysis were cerebral activations are observed when compared with the other cerebral regions.