Disturbing experiences don’t actually heighten our perceptions. In fact, according to new Weizmann research, in adverse conditions we’re more likely to experience slightly different sights or sounds as being the same. The scientists think that this lumping together of similar sensory stimuli may be behind post-traumatic stress syndrome. The experiments showed that volunteers learning to distinguish between similar tones had much more trouble telling them apart when these were associated with a shockingly bad smell. Dr. Rony Paz explains that this blurring of our perceptions may have helped our long-ago ancestors to survive in the real jungle, when instinctively running away at any sound that even remotely resembled the rustle of a top predator may have made sense. But in our modern sensory jungle, that same tendency could make any loud noise evoke the same gut reaction as gunfire, or any building seem ready to fly apart in a fresh disaster.

image: Schuyler Shepherd, wikimedia commons