Brain Activity During Defensive Reactions to Virtual Threats

The study of brain activity under the appearance of an unexpected visual threat can give some insights into how the brain reacts to potential dangers, and how the consequent defensive response is originated. In this study, a virtual reality (VR) scene is used to present an unexpected threat aiming to invoke a defensive reaction, as well as non-threatening stimuli as control. The brain activity is measured along the pre and post stimuli conditions using electroencephalography (EEG). The goal is to identify how the information propagates between cortical regions once the threatening situation is presented. The functional connectivity study evidenced a flux of information from the left middle temporal gyrus to the premotor cortex, evidencing a defensive response induced by the sound involved in the stimulus. Additional connections involving diverse cortical areas as the left inferior frontal gyrus, the primary motor cortex, the prefrontal cortex, beside the premotor cortex may represent part of the information flux involved in action planning. Other activated cortical areas were the supplementary motor cortex, the right temporal gyrus, the associative visual cortex, and primary somatosensory cortex. Concluding, the immersive scenario provided by VR allowed to induce more natural defensive response, and consequently the identification of relevant brain activity.