Objective Illusion

On a hike, Alison and I came upon this rock that we both perceived as a man’s face.

However, it soon became clear that while we both saw a face, we each saw a different face.

Alison's face:

Brandon's face:

This reminded me of the famous picture of the old or young woman. You can manipulate what face people will see (old or young) by having people read a biased description of what they should see (a description of a young woman or a description of an old woman).

It is a safe statement to say that most of us think that reality is objective in that it is something we perceive with one of our senses, the eye for example. However, an individual’s perception of the world is not simply an objective truth experienced through the senses; rather, humans and other animals use a combination of (1) sensory information, (2) psychological mechanisms, and (3) past sensory information to construct a conscience view of a world that can then be called reality. These constructed perceptions of the world can be different for different individuals and all can be considered “reality.”

Perhaps you are wondering what a psychological mechanism is. To understand this we must turn to evolutionary psychology. You have probably had an experience in which your leg brushes up against something (perhaps a blade of grass or a stray thread on a couch) and you instantly pull your leg away and simultaneously swat at the area to kill the “perceived insect”. In this example the (1) sensory information is the blade of grass, (2) the psychological mechanism is thinking it must be an insect (perhaps a spider) and (3) based on past experience, perhaps the grass felt more like an insect crawling on you than a blade of grass. The difference between 2 and 3 is that 2 requires no prior experience. Rather the experience of your ancestors (who by your existence) proved that when it comes to feeling insects on your leg, it is more adaptive to be wrong in your perception (to slap your leg to kill a perceived spider that happens to be a blade of grass) than to be right and take no action (thinking the itchy sensation is grass when it is really a black widow).

Hopefully you are not more confused about psychological mechanisms. It would be useful to know that they are analogous to physical reflexes, have a physiological counterpart and can be considered instinctual. As to the development of psychological mechanisms it is important to know that neurons that fire together wire together. It would also be useful to have a knowledge of natural selection and selection pressures. Also, if you are interested in the psychological mechanism of facial recognition (since that’s what happened when we looked at the rock), this mechanism’s physiological counterpart is in the fusiform face area (FFA) and you may be interested to read about prosopagnosia.

In other news...Alison made peach cobbler! It was delicious if she does say so herself. (She also says: Many thanks to Cindy for sharing part of your peach purchase!)