The Truth of Perception

by Jackie Genova

There is a distinct difference between what we see and what we think we see. We take in information from our senses but this information may not be as accurate as one may hope. Most people when they think about how your brain takes in information would assume that their senses are activated by something in the environment and then process this information and interpret it. In other words, we take in information from stimuli in the environment, and then perceive the meaning after, this is known as bottom-up processing. While this is true and does occur very commonly, there is also top-down processing, “A perceiver understands a particular moment depending on how they can bring…knowledge to bear on the immediate stimulus,” which is an element as to why people react and store sensory information differently (Annu).

One example of sensation and then perception would be entering a kitchen that smells of chocolate and then you think about a memory of your mother baking brownies and the similarity between the scents. Our visual cortex has one example of sensory adaptation when a stimulus in the environment becomes a constant, so we adapt to it. Everybody knows the feeling of when you leave a movie theater and get blinded by the bright lights, and then after a few minutes your eyes adjust, and your surroundings appear normal.

Sometimes our sensations do not always trigger perception. Think about how many external stimuli are triggering our sensory systems simultaneously. When you walk outside your house, you feel the door shut, hear the dog barking, smell the grass clippings, and see the cars drive past. You are constantly interacting with new sensory stimuli, so your sensory cortexes must tune out other less important stimuli to allow you to focus on one factor. This is called the cocktail party effect; everyone knows the scenario of when you are chatting with someone at a party, and then you turn around when you hear someone say your name. This is not because you are not fully listening to the conversation you are in but because our auditory cortex is constantly scanning for more important information that we may need to be aware of.

Since our brain is always scanning through stimuli, in order to better remember, you need to focus your attention. Focusing will help tag a detail to be remembered. Other ways to help tag details are to remember to cluster and relate information and to make sure you understand the information you are trying to remember. People can experience selective attention when they are trying hard to focus on something then other details will not be encoded since they are not trying to remember them.

Most people see the photo on the left and observe a square which is not entirely accurate. Our perceptual system will use context to explain the scenario. Involving the image, we use context to fill in the gap that is a square in the middle of the circles. Similarly when trying to recall a memory and there are missing details, your brain will fill in these gaps with details that make sense in the context of the memory. For example, imagine you are telling a story about going to the beach, and you try to describe the scene. You can list the sunny weather, the hot sand, and the cold ocean water, but these are all context-dependent details that your brain could have implemented.

This is why people must be aware that their memories are not facts. People's perceptions can be tricked, and are not as true to fact as people think. This idea of your memory not being truthful relates to your perception of details as well as the environment you grew up in. Depending on a person's culture, you will prioritize different elements of memory. For example, in Western cultures, it is all about having a good story so people will dramatize a memory. While Eastern cultures pride themselves on accuracy and try to keep the details more realistic.

Plato had this scenario where a small group of people were trapped in a cave. They are chained facing a wall, backlit by a fire, where shadows are displayed on the wall. These shadows are all the trapped people know; It is their only reality. Then, two of the trapped people are freed and venture out of the cave. They find the truth of life when they see the light and return to the cave to enlighten the others. But the others criticize the two enlightened people and call them insane. Plato used this analogy to show the drastic difference between reality and perception and how it differs from person to person.

The cave and shadows are all the people know, so it makes sense that they would reject the others who speak of things they have never seen before. However, the enlightened two can not go back to the life they once believed in while living in the cave. The people in the cave have a different reality than those who were freed because of their perceptions. It does not matter which belief is true or false because people believe their perceptions. This confidence in memory is a trouble in many aspects of life which can lead to many misunderstandings. It is necessary to be aware that memories can be faulty.

The infographic on the left represents the results of a survey questioning different groups if they believed that memory works like a tape recorder and you can accurately recall details. Approximately 60% of the general public seem to agree that our memory accurately records every aspect of our lives. As supported by the optical illusion and the definition of perception involving memory distortion, the majority of the general public are misinformed. To reduce misunderstandings, for example in eyewitness testimony, society must be educated on the reliability of the human memory. We take in information from our surroundings, but our perception can enhance and suppress details. Every person takes in sensory information, which gets perceived differently from person to person. Our sensory systems allow us to take in information from the environment, and our perception is what gives an interpretation of the world around us.