card
378
perception
OLogy Series
biology
card
378
perception
OLogy Series
biology

You are sitting outside, watching a baseball game. You sniff the air and recognize a familiar scent—hot dogs. You look around and sure enough, there is a hotdog seller passing by. Suddenly, you hear the crack of a bat, then a cheering crowd. It's a home run! In just a matter of moments, you have understood a great deal about your surroundings. Your senses send signals to your brain, and it is up to your brain to reconstruct the events that triggered the signals. The experience your brain recreates is known as perception.

An Insightful Experiment

In the 1970s, a scientist named Stephen Palmer conducted an experiment. He wanted to see how expectations influence perception.

First, Palmer showed volunteers a picture of a setting—for example, a kitchen. Then he quickly flashed another drawing and asked them to write down what they saw.

When the second drawing was something that belongs in a kitchen, like a loaf of bread, it was easy for most volunteers to identify. They got it right most of the time. But when the second picture was a mailbox or drum, many of the volunteers got confused. They had just looked at a picture of a kitchen, and they weren’t expecting to see a mailbox or a drum.

Palmer’s experiment shows that expectations can affect how you experience your surroundings. Your brain does not passively receive information from your sense organs. It actively creates what you perceive.

When looking at the Mona Lisa, a portrait painting of a woman, what are people most likely to focus on first?

her face

her hands

the landscape in the background

Are you right?

Correct!

Where you focus your attention depends on many factors. Humans are hardwired to notice certain things, like faces and movement, because noticing them helped our ancestors survive.

To taste the flavor of your favorite kind of ice cream, you use:

just your tongue

your tongue and your nose

your tongue, your nose, and your brain

Are you right?

Correct!

When you enjoy a scoop of ice cream, you are not just using taste buds on your tongue. You are also using scent detectors in your nose. As you eat, odor molecules drift from your throat to the back of your nose. Receptors in your nose then send signals to your brain, which creates the sensation of flavor.  

When you see an object, what you are really seeing is:

it's outline

it's shadow

the light bouncing off it

Are you right?

Correct!

You see when cells at the back of your eyes detect light waves reflected from objects. These cells react to brightness, shadow, and the wavelength—or color—of the light. Then they send signals to your brain. Your brain interprets the information and forms an image.

The color of what you drink can affect how it tastes.

Fact
or
Fiction
?

Fact

One sense can influence another. For example, sugar water is perceived as tasting more sweet when colored red and more sour when colored green!

Hearing is the same as listening.

Fact
or
Fiction
?

Fiction

You can hear many sounds at once, but you can only listen to one or two sounds at a time.

Definition: an awareness of your surroundings that is based on information from your senses

Top Sense: Much more of the human brain is devoted to vision than to any other sense.

Cool Fact: Your brain overrules your senses all the time. For example, when an image is incomplete, your brain figures out the most likely interpretation and generates an image of that!

Cool Fact: Using an MRI scanner to see images of the brain, scientists can tell whether you are looking at a photo of a beach, a city street, a forest, a highway, a mountain, or an office. They can do this by looking at what part of the brain is especially active and by analyzing the patterns created by firing neurons.

Image credits: icons, © istockphoto.com.