EEG changes affected by trauma related to earthquakes

Posttraumatic stress disorder (PTSD) has steadily grown in Japan since “The Great Hanshin-Awaji Earthquake” in 1995. The aim of this paper is to assess whether personality stability can affect brain reactions evoked by earthquake traumatic stimuli or not. The personality stability of 22 healthy subjects was evaluated, and the subjects were categorized into two groups: the “mentally stable group” (M-S) and the “mentally unstable group” (M-US). An EEG was measured during resting and under tasks related to fear from earthquake in ‘quake’ session or generally unpleasant feeling in ‘fear’ session. The results show that the power spectra values of M-US in quake and fear sessions were significantly larger than those in resting session, while there were no significant changes in the power spectra values of M-S in any sessions. These events suggest that traumatic stimuli can provoke not only emotional reactions, but also brain reactions especially in mentally unstable people.