Our brain gathers information from our senses in order to experience and understand the world around us. The various nerves located all throughout our body gather this information and send it to the brain through a network of neurons. This information is gathered from all over your body: the way an ice cube feels when you touch it with your hands, how the ocean sounds when you listen to it with your ears, how the sky looks when you see it with your eyes, and even what the ground feels like when your feet touch it. After receiving all of this information about the world around us, the brain processes it so that we have an understanding of that world.

The McGurk effect demonstrates how our senses work together so that what you hear is affected by what you see. To experience a demonstration of the McGurk effect, click play. You will need to be able to hear the demonstration for it to work properly, so make sure your computer speakers are on, or your headphones are plugged in.

Context

Context is what something is surrounded by, its setting. For example, if something is not in its usual place it can be said to be out of context.

Context is often used when deciphering new words. We can sometimes figure out what a new word means by the words we know around it.

Take a look at the animation. The letters on each side are easy to read, but the center letter is harder. Your brain can see that 'H' fits with 'T' and the 'E' to make the word 'the' and it can use this to fire the neurons that tell you that the middle letter is 'H'. In the same way, when we later see the letter 'C' and 'T' surrounding the middle letter, your brain sees that 'A' fits with them to make the word 'cat'.

Imagine the things that the brain does: storing memories, coordinating muscle movement, and formulating responses to verbal questions. Now imagine the brain doing these things without input from the surrounding environment. This mental exercise shows that many of the brain's functions rely on receiving information about the outside world. But, how exactly does information get from the outside world to the brain? The simple answer is through the eyes, ears, nose, mouth, and skin. In reality, each of these sensory organs is made up of special cells that begin signals and transmit them to the brain.

The McGurk effect demonstrates how our senses work together so that what you hear is affected by what you see. To experience a demonstration of the McGurk effect, click play. You will need to be able to hear the demonstration for it to work properly, so make sure your computer speakers are on, or your headphones are plugged in.

How is sensory information transmitted to the brain?

When information enters the body, it is “captured” by a sensory receptor. In response to something such as sound, taste, or another sensation, the sensory receptors create an electrical signal that is sent through a network of neurons. Some of these neurons extend to the brain, and so through these neurons, the signal reaches the brain.

How Does Sight Work?

The process of sight occurs exactly how the other senses occur: sensory receptors create signals and transmit them to the brain through a network of neurons. But, it also has many specialized details that make it unique.

At the very back of the eyeball is the retina, a structure composed of nervous tissue. Light travels through the eye and to the very last layer of nervous tissue in the eye—the sensory receptors. These sensory receptors respond to light. Different receptors respond to different qualities of light: one type responds to contrast and motion and another responds to color and detail. In response to light, these sensory receptors begin an electrical signal and synapse with neurons in the retina. The axon of the last neuron in the retina, the one closest to the front of the eye, transmits the signal to the visual centers within the brain.

How are electrical signals transformed into our understanding of the world around us?

Scientists continue trying to puzzle through how the brain creates an unwavering 3-D image out of the signals received from the retina. Through their experiments, scientists discovered that there are different areas in the brain that deal with different types of information: one for color, one for form, and one for motion. But they are currently unsure as to how these different sections create one image together.

Scientists know that the brain uses context to interpret all the visual impressions it receives and to construct its understanding of the visual world. Just as you can determine what a word is from the words around it, your brain can determine something that is unclear from what surrounds it.

Take a look at the animation. The letters on each side are easy to read, but the center letter is harder. Your brain can see that 'H' fits with 'T' and the 'E' to make the word 'the' and it can use this to fire the neurons that tell you that the middle letter is 'H'. In the same way, when we later see the letter 'C' and 'T' surrounding the middle letter, your brain sees that 'A' fits with them to make the word 'cat'.