Impact of Slow Breathing on Markers of Stress in Response to a Virtual Reality Active Shooter Drill

For this study participants will be randomly assigned either slow breathing 1 [(SB1); four second inhale, two second pause, four second exhale, two second pause, repeat for five minutes] or slow breathing 2 [(SB2); four second inhale, two second exhale, repeat for five minutes]. The breathing intervention will take place five minutes prior to the start of the virtual reality based active shooter drill. Researchers will compare the two groups in terms of change in heart rate (HR), blood pressure (BP) subjective stress [(SAI); state-trait anxiety inventory], and salivary markers of stress before and after the breathing intervention and virtual reality active shooter drill (VR-ASD).

All procedures were reviewed and approved by the University Institutional Review Board.

Experimental procedures upon arrival to the testing site, subjects will be instructed to rinse their mouth with water and rest in a quiet room for 10 minutes. Immediately after the 10 minutes of rest period, an initial saliva sample, HR & BP (Suntech, Hauppauge, NY, USA) and SAI measures were collected (30 min prior to VR-ASD). Throughout the experimental session HR, BP, SAI, and saliva samples will be collected a total of four times : 1) 30 minutes prior to start of the VR-ASD, 2) 5 minutes prior to the start of the VR-ASD (immediately before the breathing intervention) 3) 5 minutes post VR-ASD (immediately post breathing intervention), and 4) 30 minutes post VR-ASD.

Virtual Reality- Active Shooter Drill (VR-ASD):

This is a virtually reality simulation, the participant will put on the VR headset and carry a Glock 17 training pistol, they will be able to physically move through the entire ASD without interruption. The VR lab is larger than the virtual environment (~35 x 20 ft). The participant will physically walk down a ~10-foot-long virtual hallway where they will encounter 2 simulated wounded victims. One will be on the ground with traumatic injuries and the second victim will 'run' out of the attack room with gunshot wounds to his/her left arm and leg. Once at the threshold of to the attack room, they will observe one victim on the ground with a traumatic head injury and the shooter firing his handgun at the last victim. If the subject hadn't fired his/her weapon yet, the shooter would turn toward the participant to elicit a response, the participant will " fire" a shot if needed. The shooter will fall after being shot.