EEG Analysis:
Data analysis was based on brain responses evoked by the different brake lights simulation.The EEG data recorded from channel Pz was utilised for this purpose. The brain response component P3 (also known as P300) is evoked during decision making processes that occurs in the brain when the subjects decide to lift their foot from accelerator and depress the brake pedal. P3 component is maximal is mid-line parietal and hence the selection of Pz for the location.The EEG data is filtered from channel Pz (for noise reduction) from 0.1 to 8 Hz using Infinite Impulse Response filter to remove the baseline noise and moreover as P3 is a low frequency component. Next, the EEG is segmented into 45 segments, each corresponding to one brake light activation (as there were 45 brake light activations per brake light 45 for each subject). Each segment of 1.2 seconds is obtained for the period of 0.2 seconds before the brake light onset and 1 second afterwards, which is sufficient to capture the evoked brain responses. The segments are averaged to reduce EEG components that are not time-locked to the brake light cognitive processing.
