The illusion of borrowed time
The sensation is a common trope in stories of survival: during a car crash or a terrifying fall, the world seems to slow down. Events that unfold in milliseconds feel stretched into long, clear moments, a phenomenon sometimes called tachypsychia. For years, the common explanation was that the brain somehow sped up its processing, allowing a person to perceive more information per second. This theory, however, runs into a problem. There is no evidence that our perceptual abilities actually increase during a crisis.
An important set of experiments by neuroscientist David Eagleman tested this directly. Participants were dropped from a height of 50 meters into a net. During the 2.49-second free fall, they wore a device on their wrist called a perceptual chronometer, which flashed numbers faster than the human eye can normally register. The hypothesis was simple: if time perception truly slows, the falling participants should be able to read the numbers. Yet, none could. Their temporal resolution—the speed at which they could gather visual information—did not improve, even as they reported that their own fall seemed to last 36% longer than watching others fall from the same height. The conclusion is that the slow-motion experience is a memory illusion, not a perceptual one. an illusion of memory.
Your amygdala's secondary memory system
The feeling that time has expanded is a result of recollection, written into your neural hardware by a small, almond-shaped region of the brain called the amygdala. Research institutions in Zurich, such as ETH Zurich and the University of Zurich, are deeply involved in studying the neural mechanisms of memory and emotion. The amygdala is central to processing fear and other strong emotions. When you experience a life-threatening event, it goes into overdrive.
This intense activation of the amygdala essentially functions as a "save this" command for your brain's memory systems. It triggers the release of stress neurotransmitters like norepinephrine, which changes the electrical patterns in the amygdala's circuits and shifts the brain into a state of heightened arousal that helps form very dense, detailed memories. This secondary memory system records a much larger dataset than it does during normal circumstances.
When you later recall the event, your brain accesses this unusually dense memory file. The sheer volume of detail tricks your conscious mind into concluding that the event must have taken longer to unfold than it actually did. A two-second event is replayed in the mind with the detail of a ten-second one, creating the powerful illusion of slow motion. The memory isn't wrong; it's just unusually detailed. The research shows that subjective time is not a single, unified thing that can speed up or slow down, but a complex construction of perception and memory.