Are You Afraid of the Dark?

Our Cognitive Ability to See Movement in Pitch Black Conditions

Imagine being in a pitch black room wearing an industrial strength blindfold being clearly unable to see. Surely such conditions would not allow for any movements to be perceived due to the lack of light.

How is it then that when subjected to these conditions, cognitive experiment volunteers reported seeing movements? The answer lies in a cognitive study which suggests the mind is able to trick the eyes into perceiving motion that is truly unperceivable.

When subjected to situations in which we are unable to see, our eyes make rigid and jerky movements. This occurs due to the eyes’ inability to focus because of the deficiency or complete lack of light at the time. In the presence of light when we are able to focus on a moving target, our eyes produce smooth movements.

In order to record the eye movements of the experiment volunteers, computerized eye trackers were employed. This advanced technology was able to confirm the smooth eye movements of volunteers who claimed they were able to see movement in pitch black conditions.

Interestingly enough, not only do smooth eye movements detect motion, but because they only occur when our eyes are following a target, the volunteers were able to clearly follow their arms moving in front of them.

Siri Chintapalli, a sophomore biology major, said, “I feel that it is possible to see such movements in the dark because you instinctively know where all of your body parts are. That, combined with how many times you’ve seen your own arms, would allow for the illusion of seeing in the dark.”

The incidence of this illusion is seen in other instances as well. Often missing limbs or amputations induce an effect of a phantom limb. Phantom limb is described as the sensation that missing body parts or organs are still attached to the body and are continuing to move accordingly with normal body movements.

Dr. Brad Ingebrethsen, professor of physics, said, “Somehow this doesn’t surprise me.  If the brain can experience phantom limb sensations or hallucinations, it would seem capable of filling in the missing piece in a set of linked sensations that it has experienced every day over a lifetime.”

The incredibly strange workings of the mind continue to baffle us in this regard and the cognitive science behind it offers many possible explanations.

Our perception of vision arises from the intricate processing of visual signals that occurs in the retina and the optic nerve. There is a structure at the back of the eyeball known as the optic disc which is the point at which nerve cell axons exit the eye and travel down the optic nerve toward the brain. The optic disc a region void of all photoreceptors, receptor cells which detect light, and is therefore referred to as “the blind spot.”

Kerianne Fuoco, a sophomore clinical lab science major, said, “The location where optic nerve exits the eye creates a blind spot. However, individuals may not experience a hole in their vision due to the brain’s ability to fill in the missing visual information. Therefore, the results of this experiment are not so surprising that the brain is able to fill in that visual information even in the absence of light.”

It is quite amazing what our minds are able to accomplish in conditions which are supposedly unfavorable. And with discoveries such as these, we see that there are truly no limits to what our cognitive abilities are capable of.