Defensive behavioral reactions evoked by pictures of urban violence

After the perception of a threat, a sequence of defensive motivational behaviors is triggered in a process described as the `defensive cascade`. The first behavior observed is freezing, followed by fight-or-flight responses and tonic immobility. The progression of these defensive reactions is according to some characteristics, such as the proximity of the threat. In the human neurobiology, it is possible to study defensive emotional responses by using pictures where the perception of the proximity of the threat can be modulated by varying the direction of the threat stimulus. Studies in this area are still scarce, but the understanding of defensive behaviors in face of urban violence is extremely important, since the number of violent deaths is expressive in Brazil.