“The single distortion under fire that Artwohl heard about most, with a full 84 percent of the officers reporting it, was diminished hearing. In the jarring, electrifying heat of a deadly force encounter, Artwohl says, the brain focuses so intently on the immediate threat that all senses but vision often fade away. ‘It’s not uncommon for an officer to have his partner right next to him cranking off rounds from a shotgun and he has no idea he was even there,’ she said. Some officers Artwohl interviewed recalled being puzzled during a shooting to hear their pistols making a tiny pop like a cap gun; one said he wouldn’t even have known the gun was firing if not for the recoil. This finding is in line with what neuroscientists have long known about how the brain registers sensory data, Artwohl explains. ‘The brain can’t pay attention to all of its sensory inputs all the time,’ she said. ‘So in these shootings, the sound is coming into the brain, but the brain is filtering it out and ignoring it. And when the brain does that, to you it’s like it never happened.’
“The brain’s tendency to steer its resources into visually zeroing in on the threat also explains the second most common perceptual distortion under fire. Tunnel vision, reported by 79 percent of Artwohl’s officers, occurs when the mind locks on to a target or threat to the exclusion of all peripheral information. Studies show that tunnel vision can reduce a person’s visual field by as much as 70 percent, an experience that officers liken to looking through a toilet paper tube. The effect is so pronounced that some police departments now train their officers to quickly sidestep when facing an assailant, on the theory that they just might disappear from the criminal’s field of sight for one precious moment.
“According to Artwohl’s findings, the warping of reality under extreme stress often ventures into even weirder territory. For 62 percent of the officers she surveyed, time seemed to lurch into slow motion during their life-threatening encounter – a perceptual oddity frequently echoed in victims’ accounts of emergencies like car crashes. In a 2006 study, however, the Baylor University neuroscientist David Eagleman tested this phenomenon by asking volunteers to try to read a rapidly flashing number on a watch while falling backwards into a net from atop a 150-foot-tall tower, a task that is terrifying just to read about. This digit blinked on and off too quickly for the human eye to spot it under normal conditions, so Eagleman figured that if extreme fear truly does slow down our experience of time, his plummeting subjects should be able to read it. They couldn’t. The truth, psychologists believe, is that it’s really our memory of the event that unfolds at the pace of molasses; during an intensely fear-provoking experience, the amygdala etches such a robustly detailed representation into the mind that in retrospect it seems that everything transpired slowly. Memories, after all, are notoriously unreliable, especially after an emergency. Sometimes they’re eerily intricate, and yet other times vital details disappear altogether. ‘Officers who were at an incident have pulled their weapon, fired it, and reholstered it, and later had absolutely no memory of doing it,’ Artwohl told me. If your attention is focused like a laser on a threat (say, the guy shooting at you), Artwohl says, you may perform an action (such as firing your gun) so unconsciously and automatically that it fails to register in your memory banks.”