People are really easy to fool. It's not necessarily insanity, but rather confusing stimuli. People can interpret certain stimuli completely wrong. The thing is, the things we 'see' are pure reconstructions by the brain of the visual input - not the photons themselves. And sometimes the signals screw up our visual system, making us see weird shit mainly because the brain is trying to interpret the signal in one way and trying it's best to maintain this interpretation. This is not hallucination as such, it's just visual system getting confused.
Personal experience:
1) when my son was 2, I woke up in the middle of the night and thought I heard something. I went to check his room. As I peered through the door I was 100% convinced I saw him walking in the room. But as I entered the room I realized that was not possible as he was several meters away from the position, a sleep. The carpet on the room was really colourful playmat. As I retraced my steps I realized the patterns on the carpet in the near darkness were close enough for my brain to interpret the visual signal as my son walking. In another circumstance I could have easily thought I saw a ghost (if I was so inclined).
2) This is even more weird. I give you the mating crows. I walked by some familiar trees planted next to an office building in bright daylight and noticed something black moving in one of them. I could not see immediately what it was until I realized it was two crows which appeared to be mating or fighting - and as I did not hear anything I guessed the latter. Being the curious naturalist I am I approached tree. Yep, crows. I tried get as close as I could - until I was right next to the tree and noticed the "crows" were actually a black plastic bag wriggling in the wind. This illusion was so convincing and powerful I've never been fooled so well by anything else.
So, what do I conclude? I'm 40, and in the past 20 years I've seen two times strange events that I could have easily intepreted as proof of supernatural activity if I was so inclined - ghosts and some weird magic transfiguration.
Based on this sampling, it's quite likely people have 'witnessed' all sorts of strange things their visual cortex has produced. I totally now believe people have actually seen ghosts - except it was all in their head and they weren't crazy - just their brain doing what it always does and missing the context a bit.
Also makes you think how reliable eye witness statements are in some contexts that have short span and potential for confusion.
Personal experience: 1) when my son was 2, I woke up in the middle of the night and thought I heard something. I went to check his room. As I peered through the door I was 100% convinced I saw him walking in the room. But as I entered the room I realized that was not possible as he was several meters away from the position, a sleep. The carpet on the room was really colourful playmat. As I retraced my steps I realized the patterns on the carpet in the near darkness were close enough for my brain to interpret the visual signal as my son walking. In another circumstance I could have easily thought I saw a ghost (if I was so inclined).
2) This is even more weird. I give you the mating crows. I walked by some familiar trees planted next to an office building in bright daylight and noticed something black moving in one of them. I could not see immediately what it was until I realized it was two crows which appeared to be mating or fighting - and as I did not hear anything I guessed the latter. Being the curious naturalist I am I approached tree. Yep, crows. I tried get as close as I could - until I was right next to the tree and noticed the "crows" were actually a black plastic bag wriggling in the wind. This illusion was so convincing and powerful I've never been fooled so well by anything else.
So, what do I conclude? I'm 40, and in the past 20 years I've seen two times strange events that I could have easily intepreted as proof of supernatural activity if I was so inclined - ghosts and some weird magic transfiguration.
Based on this sampling, it's quite likely people have 'witnessed' all sorts of strange things their visual cortex has produced. I totally now believe people have actually seen ghosts - except it was all in their head and they weren't crazy - just their brain doing what it always does and missing the context a bit.
Also makes you think how reliable eye witness statements are in some contexts that have short span and potential for confusion.