1. The McGurk Effect – One of the trippiest illusions ever?
What you perceive isn’t always necessarily what is true. The McGurk effect is a phenomenon that occurs when the brain attempts to interpret an external occurrence by piecing together various pieces of sensory information.
The following clip explains and demonstrates the effect, and it’s almost too strange to believe.
2. A divided mind – the effects of split-brain surgery.
The corpus callosum is a small piece of neural tissue in the centre of the brain that connects and links the brain’s two hemispheres. When the corpus callosum is doing its job, the two hemispheres of the brain pass information back and forth to perform complex tasks. However, when this organ is split or damaged, things start to get weird.
Simple acts like recalling the name of something based on the stimulus it produces (naming colors or sounds, for example) becomes difficult or impossible for those with a split corpus callosum.
For example, when two very similar auditory stimuli are presented to the patient’s separate ears, they can identify what the stimulus is through one ear, but not through the other. (Source). Even scarier, the same thing occurs with vision: “When split-brain patients are shown an image only in their left visual field… they cannot vocally name what they have seen.” (Source)
3. Blindsight – Seeing but not seeing, a really weird visual impairment.
From Scholarpedia: Blindsight is defined by the Oxford Concise Dictionary as ‘a condition in which the sufferer responds to visual stimuli without consciously perceiving them.’ ” In other words, patients suffering from this strange form of visual impairment both can and can’t see, simultaneously. Certain stimuli might make a blindsighted person react, even though they themselves would claim that they’re not seeing anything at all.
Imagine, for example, if you threw a ball to a blindsighted person – they might react perfectly and catch the ball, but then they’d tell you that they didn’t actually see the ball. Spooky.
As reported here in Scientific American, experiments show that individuals with blindsight react to emotional/facial cues shown in pictures that they themselves can not consciously perceive. In other words, their brain was processing and “seeing” the emotions on the faces they were presented with, even through their blindness.
4. Sleep Paralysis – The human mind at its scariest.
While we sleep, the brain relaxes our bodies to the point of paralysis so that we don’t move around too much and potentially injure ourselves. Fortunately, most of us are in a state of deep sleep when this happens.
Sometimes though, individuals may find themselves in a state between conscious wakefulness and deep sleep, a state where the body is paralyzed but the mind is alert and awake. This is called sleep paralysis, and apparently it can be pretty terrifying.
In this state, the individual is trapped in their bed, and trapped in their bodies. To make things even creepier, the mind might begin to conjure vivid, lifelike hallucinations which often take the form of malevolent beings. Maybe this phenomenon can explain experiences of alien abduction and other paranormal phenomenon?