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Instant 'After-images' on the Retina?


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I'm curious as to how Neuroscience explains this one, or if my assumption is correct--being after-images.

 

My eyes are very sensitive to light, and as such this seems to come with it's own odd characteristics. I see trails behind objects illuminated by even a faint light, while they're in front of a reasonably dark backdrop.

 

For instance, right now, I can move my had in front of my black speakers, in this dimly lit room, and there is an in-tack silhouette of my hand that follows a few cm behind it which appears translucent and turquoise.

 

Another example is when I've played glow-in-the-dark miniature golf. I'd see two golfballs instead of one when it moved. I think the actual golfball was neon yellow, but the image of it that followed a few inches behind was green in colour--there is more distance between the after-image and the object depending on the speed of the object.

 

So basically, what's this called? Is there an actual term for seeing instant after-images with such sharpness and consistency? My theory is obviously just that, after-images. However, I am also uncertain whether this is due to my brain, or eyesight (physical eyes) alone.

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funny, but it's about an input device not an output device.

 

Compared to a camcorder I would say you have a low shutter speed (explains the sensitivity)

 

Not sure but an afterimage is when your eye sensors stay activated for a while after the light source stopped.

 

You can compare it with a very loud sound that makes you hear 'noise' when it's already silent.

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Don't know a name.

 

If you keep seeing trails all over the place (during the day) then you may contact a doctor.

It could be normal for your brain/eyes but it could also be a sign for something else that isn't right.

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I'm aware. Though, the way I saw it isn't exactly common. I've asked around. I mean I saw two golf balls clearly, not a light haze or blur.

 

Although you're correct, I also see the same trails while in well-lit rooms as long as the object moves in front of a reasonably dark background. Sometimes the colours are different, too, which is odd. When I'm in a very relaxed state, the colour of the image behind my hand sometimes appear violet. I tested it in front of my black cat while in a fully lit room in more occasions that one, and the colour was different. It even seemed to shimmer once. In another occasion, I saw a "field" extending a few mm from the outline of my fingers, without even moving my hands. It was violet as well. This happened when I was in a more relaxed state of mind.

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"So basically, what's this called? Is there an actual term for seeing instant after-images with such sharpness and consistency? My theory is obviously just that, after-images. However, I am also uncertain whether this is due to my brain, or eyesight (physical eyes) alone."

 

it`s called "image retention" it`s due to this occurance that we see television or cinema films or cartoons as one moving image and not a flicker of several different images, it gives it the illusion of motion continuity and is perfectly normal :)

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Skye said in post # :

Neurons can have long term changes if they are stimulated beyond a threshhold which activates a biochemical feedback loop.

 

Number three here:

 

http://www.ncbs.res.in/~faculty/upi.html

 

What would constitute stimulation in this case (for my vision)?

 

Also, I'm assuming 'biochemical feedback loop' refers to the mental process which explains why I'm seeing translucent, coloured silhouettes trail behind objects?

 

YT2095 said in post # :

"So basically, what's this called? Is there an actual term for seeing instant after-images with such sharpness and consistency? My theory is obviously just that, after-images. However, I am also uncertain whether this is due to my brain, or eyesight (physical eyes) alone."

 

it`s called "image retention" it`s due to this occurance that we see television or cinema films or cartoons as one moving image and not a flicker of several different images, it gives it the illusion of motion continuity and is perfectly normal :)

 

What you mentioned is normal, true, but from what I can perceive it doesn't explain the trail behind objects and changing colours while in more relaxed states of mind; instead, just what you explained about seeing images from film/tv/etc. in one blending stream.

 

I'm lookin for some kind of documentation that uses terms or ideas from neuroscience, rather than computer science and such (ex: "image retention") to explain the aformentioned occurance. I do appreciate the suggestions, though.

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I believe they are untechnically called "tracers" and I have only seen mention of this is relation to LSD. Ever taken LSD? Many people that have can continue to experience these tracers beyond the normal level due to receptor changes induced by the drug in the visual pathways of the brain.

 

If you have used LSD, then it is normal for you to still see the tracers sometimes- along with the slight color effects you describe. Look up HPPD if interested. If you have not taken LSD (or other hallucinogens of a similar sort), then it is probably still normal- just an exageration of how the visual system normally works; you are in that small percentage of the natural variation in the population. This is simply a guess...I don't know. I suppose it could be involved with the eye itself, but I am not sure how.

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I appreciate the mention of LSD, for the reason that in my research I've also noticed that the things I experience can be related to symptoms of LSD usage in many ways--I didn't explain everything I "see". However, I've never taken LSD, illegal drugs, or perscribed drugs that can result in this side-effect. So it does kind of baffle me at times. :)

 

During my research for alternative expanations I've come up with some more information. It relates to the pineal gland being the main cause for the specific things I see, which are not limited to "after-images" (btw, Skye, thank for that link). I won't get into it here, though, but if anyone wants to comment on that, feel free.

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  • 1 year later...
  • 3 months later...

The brain uses opponent processes to create after-images. About 2,300 years ago Aristotle reported a motion after effect after looking at a water fall then at the forest. To his surprise he saw the trees going up into the air.

 

The brain normally develops a weighted Gaussian history of a stimulus input and will produce an opponent output of that stimulus equal to approximately the average of the input. The opponent output declines or habituates. Any opponent output will form an overwrite on to a stimulus input.

 

Technically speaking all opponent processes are due to habituation of an input which is always stimulus specific.

 

The Correlational Holographic Opponent Processing model http://u2ai.us suggest that the brain forms holograms acting like wavelet filters for information processing. Wavelets can be formed by stimuli and from opponent processes. An anti-wavelet memory cancels out an incoming stimulus. The brain works in zero. That is why master chess players have little brain firing patterns when playing chess.

 

In your case regarding your floating opponent process visions you habituate so fast that you have the psychological illusions of the opposite stimulus. This suggest you have a very very very high IQ in terms of short term memory. If you work hard you can develop an outstanding long term memory system. Nothing of value in will generate nothing of value coming out. :)

 

Ron Blue

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  • 4 months later...

Everyone can see a bit of IR and a bit of UV, it's just humans are so bad at picking it up that you'd need a really powerful source which isn't generally available.

 

An example to demonstrate this would be my physics teacher's teacher who once accidentally walked infront of a very powerful UV laser beam. He now has a blindspot on his eye, but he saw UV light... really saw actual UV light! He could do this because the laser beam was a very concentrated powerful UV source, so powerful that even human eyes which are not so good at detecting UV could detect this.

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