Discovering sound effect on visual memory performance based on electroencephalography

Nowadays, there are a quite study on human memory either in investigating it function, factors affect it performance and it relation with the cognitive ability. But only a few of the studies was discussed based on brain activity. Most of the study only focused on the correct response or score result of the task. Thus, this present study aims to improve the limitations. The brain response is investigates during memorization based on electroencephalography (EEG) analysis. EEG is an imaging technique that able to record the brain electrical signal in a short time. The visual working memory task with two difficulty level (easy and difficult) was preferred for experiment. Sixty healthy subjects were required to memorize the visual task at three different conditions; silent and listening to Mozart music k448 and pure white noise in 2 minutes. The sound intensity was controlled at 40 to 55 dB to minimize the effect of volume on subject. There were two measurements which were memorizing test score and brain activity was used to evaluate the memory performance of the subject. During memorizing process, the brain activity was recorded using 10-20 electrode placement system of Neurofax 9200 EEG acquisition machine. The Fp1, Fz, F8, T3, T4, T5, T6, Pz, O1 and O2 channels were selected for analyzing process by using MATLAB software. The wavelet approach was used to process the raw EEG data. Based on the result, it showed that the memory performance was influenced when the environmental condition was changing. Different pattern of EEG signal has been found for different conditions based on the relative power of frequency band.