Sensation & Perception

We perceive the world not exactly as it is, but as it is useful for us to perceive it.

SensationEnergy from the

environment that is encoded as neural signals

Two more: kinesthetic & vestibular sense

PerceptionThe process of understanding a sensation

BOTTOM-UP PROCESSING:Processing information from a stimulus

Fireworks See colors, hear sound, processed in your brain and you smile

TOP-DOWN PROCESSING:Connecting stored knowledge to the sensory

experienceProsopagnosia

Example: I need a volunteer to read!

Another example of top-down processingAoccdrnig 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.

Sensory AdaptationConstant stimulation results in decreasing

responsivenessYOUR SOCKS!If you hold your eyes perfectly still, your vision will

come and go!

Why does our body do this?Brain gets millions of messages a second, we can’t

process all of them, so we focus on the info that CHANGES!

ThresholdsAbsolute threshold: the minimum intensity of a stimulus to detect it 50% of the timeLight, sound, pressure, taste, odor

Volunteer please!

Selective AttentionYour conscious awareness focus

Senses take in 11 million bits of info per sec.You can consciously process 40 of those bits

Cocktail Party EffectIn a noisy environment, you can only focus on one

voice at a time you can’t ease drop and engage in conversation at the

same timeHowever, if someone across the room says your

name, your attention is immediately diverted

Can you sing and read at the same time?

Selective Attention while DrivingWhy did they pass the “hands free” law in

Illinois?Having a conversation is the distracting part,

NOT holding your phone! So why hands free?Because when you hit the car in front of you,

you’ll be happy you have both hands on the wheel

Passenger is still distracting but they stop talking because also aware of surroundings

Remember, most information is processed

automatically, out of sight,

in our unconscious mind!