Sooo+How+Does+Perception+Work

How Does Perception Work? According to Professor McConnell, Immanuel Kant may have been among the first to delve in to concept of Top-down Processing (2009). Immanuel Kant proposed that that incoming stimulus is interpreted with relation to our prior knowledge(McConnell, 2009).

Lets refer to one of our Guest of Honor Richard Gregory for a little help here! You can find more information on him here but for now we will just focus on his theory of Constructivism, better known as the indirect perceptual theory (McLeod, 2007).

Gregory reasoned that the only way we could accurately perceive sensory information, especially information that we have never encountered before, is through the use of prior information (McLeod, 2007). He argues that upon reception of sensory information, our brains automatically searched for patterns and tag words within our past experiences to decode and understand the present information (McLeod. 2007). This approach to perception is called top-down processing, where at the top lay all prior experiences and previous decoded stimuli and at the bottom lay new stimuli that has yet to be decoded (McConnell, 2009).

A great example of the is the illegal cursive writing scheme presented by McLeod. Upon first glanced the written upon the page just looks like jumbles lines and registers without means. However upon close examination, you can began to make out some of the words and eventually read the entire letter (2007).



This phenomena is due to the brains ability to draw associations and connections between words that it has encountered before allowing you to create a pattern of choices the word should be. In other words, the meaning of the surrounding words provides content to the unreadable text (McLeod, 2007).

Gregory looked at perception as a hypothesis, and understood that our brains perceived by making inferences about our surrounding based on past experiences to come up with a best guess of what the stimulus is that we encounter. He explained that 90% of information received by the eye is lost (an estimate created by Gregory), and our brains fill in the missing pieces of the puzzle with prior knowledge (McLeod, 2007).

This is Where Illusions Come Into Play
The formation of the hypothesis by our brains are not always correct, and under the right conditions can lead to errors. These errors create illusions as we know them today. Our brain has a tendency to associate common ideas with other already present without our brains drawing connections that may not be there in real life ( Association for Research in Vision and Ophthalmology, 2009).