Tag: phenomenon

Gabor Patches — Creating Fascinating Optical Illusions

gaborMan, I used to think optical illusions were the simple, “which line is longer” sort. But I have seen some optical illusions in the past decade or so that have really caused me pause. It’s like there’s been some sort of optical illusion renaissance recently.

Here is one of the animated variety that wouldn’t have worked presented, as they were when I was young, in book form. Wow.

Okay, I was curious, what is a “gabor element”? It turns out the “Gabor filter” has an interesting mathematical (and even biological) origin.

For the creative, there is a nice online tool allowing you to create a gabor element here. It should be possible to generate a series of them out of phase and stack them with a GIF-creation tool in order to experiment with you own illusions similar to the above.


If you’ve ever had someone brush your hair and felt tingles down your scalp, that’s ASMR. It stands for Autonomous Sensory Meridian Response, but most just know it as tingles and a relaxed feeling. ASMR is usually triggered by stimuli such as whispering, crinkling, tapping, or “squishing” noises, personal attention, and mouth noises. (I find it strange that I usually find mouth noises very irritating, but relaxing in the context of an ASMR video.) There are many more triggers, and many YouTube videos dedicated to stimulating ASMR through these triggers. Whispering is the most common trigger, and before ASMR was well-known the videos were known as “whisper videos”. Today, ASMR is much less obscure, but the ASMR community is still known as being part of the “weird side of YouTube” and there continue to be misconceptions about the sensation. For example, the scalp tingles associated with ASMR are sometimes colloquially called a “head orgasm”, and many outside of the ASMR community falsely perceive the phenomenon as being sexual in nature.

Many people will point to Bob Ross’s The Joy of Painting videos as their first experience with ASMR. It’s not hard to see why, with Bob Ross’s quiet, relaxing voice and the gentle sounds of the paintbrush on the canvas. I can’t pinpoint my first ASMR experience, but all my life I’ve found getting my hair brushed and played with to be very relaxing and tingle-inducing. Not everyone is able to experience ASMR, but even if they don’t feel tingles many people still find the videos very relaxing. However, with so many triggers, many people can find something that will give them tingles.

ASMR parody video by CollegeHumor:

The Old Hag

When I first read about sleep paralysis, also known as the Old Hag phenomenon, I was terrified. Thankfully it is more common in people with narcolepsy or anxiety, but the idea is still scary. You wake up, but you are still unable to control your body. You lie there, paralyzed. To make things even worse, the paralysis is often accompanied by terrifying hallucinations often involving a person or creature sitting on your chest.

The Nightmare by Johann Füssli

The Nightmare by Henry Fuseli, 1781.

Sleep paralysis occurs either when the person remains aware while their body shuts down for REM sleep, or when they become aware before their body has completed the REM cycle.

When a person wakes up paralyzed and vulnerable to attack, an emergency response is activated in the brain. The sense of helplessness intensifies the threat response and could account for why the “intruder” is perceived as evil.

The explanation behind the pressure on the chest, or incubus, is a combination of the muscle paralysis and the threat response. Breathing during REM sleep is naturally rapid and shallow, unnoticeable while asleep but frightening to those suffering from sleep paralysis, who are suddenly conscious of the shallow breathing and feel as if they are suffocating.

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