This week we didn’t have a lecture. During the exercise session we visited the Aalto Behavioral Laboratory and made some electroencephalography (EEG) measurements. EEG measures the electrical activity of the brain using noninvasive electrodes that are placed along the scalp. Surprisingly the most time consuming part of the measurement was the placement of the electrodes. Electrodes were embedded in a cap that was placed on test subject’s head. Blunt needles were stuck through wholes next to the electrodes in the cap and were used to move the hair and to inject conducting gel between the electrode and the scalp.
We measured the response to similar test performed during the exercise session of the fourth week. However, this time we measured the EEG when the test subject performed the test. The test subject reacted to visual and auditory stimuli and the reaction time as well as the brain activity were measured. The EEG data was visualized so that we were able to locate the activated areas. We observed that in response to the visual stimuli the visual cortex was activated and in response to auditory stimuli the auditory cortex was activated. The test subject reacted to the stimuli by pressing a button in the keyboard and therefore there was also some activation in the motor cortex.