Sensation and Perception Chapter 3 Psychophysics This is

Sensation and Perception Chapter 3

Psychophysics • This is how we experience our physical world. • Classroom demo judging weight of pill bottles. • Which one do you think weighs the most? • The more compact weight “felt” heavier to your brain when in reality it weighed the same as the large container.

Sensation • The process by which our sensory systems (eyes, ears, and other sensory organs) and nervous system receive stimuli/info from the environment • A person’s awareness of the world through their senses.

Sensation uses Bottom-Up Processing • Information processing that focuses on the raw material entering through the eyes, ears, and other organs of sensation

Perception • The process of selecting, organizing and interpreting sensory information • How you make sense of your sensory information.

Perception uses Top-Down Processing • Information processing that focuses on expectations and experiences in interpreting incoming sensory information

Read the following • Aoccdrnig to rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a total mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.

Bottom-Up vs. Top-Down Processing Follow the directions carefully! • Go to http: //jeffmilner. com/backmasking. htm. Pick a song from the list and listen to it normally (play forward). • Now listen to it in reverse. DO NOT CLICK ON “SHOW REVERSE LYRICS” • Now listen to it in reverse again, this time “Show the Reverse Lyrics” • Can you hear the “secret” message? • Why couldn’t you hear it the first time you listened in reverse? – You had no expectations. Just heard sounds. This is Bottom-Up processing! • Why could you make out the “hidden message” when you could see the reverse lyrics? – When told what to listen for the task becomes Top. Down processing! You are using your expectations!

Do subliminal messages work? • Subliminal messages make two assumptions: 1. We can unconsciously sense the subliminal (below threshold) message. - TRUE 2. Without our awareness, the stimuli have suggestive powers. - FALSE • Subliminal messages can affect how we “feel” about something for a short period of time but CANNOT persuade us to actually go out and do something. • Remember, weak stimuli have weak responses and strong stimuli have strong responses. • Extra credit to anyone who can make a coherent song that when played backwards says, “I love psychology!”

I Love Psych!!!

Did it work? • Do you really love psychology now? • It was worth a try!

Principles of Sensation • Transduction— process where physical energy is converted into neural signals • How we convert stimuli from the environment into action potential that the brain can understand.

The Major Senses • There are 6 major senses – – – vision hearing touch taste pain smell • The list can be extended with balance, joint senses and others • Vision has been studied most extensively