Sensation

Sensation

• The process by which our sensory receptors and nervous system receive stimulus from the environment.

Perception

• The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Bottom-Up v. Top-DownProcessing

NUMBER 70

What if we could sense everything?

Life would hurt.

So we can only take in a window of what is out there.

This is the study of psychophysics: relationship between physical stimuli and our psychological experiences to them.

Absolute Threshold

• The minimum stimulation needed to detect a stimulus 50% of the time.

Difference Threshold• The minimum difference that a person

can detect between two stimuli.

• Also known as Just Noticeable Difference(jnd)

Weber’s Law• The idea that, to perceive a difference

between two stimuli, they must differ by a constant percentage; not a constant amount.

Signal Detection Theory

• Predicts how we detect a stimulus amid other stimuli.

• Assumes that we do not have an absolute threshold.

• We detect stuff based on our experiences, motivations and fatigue level.

Signal Detection Theory

Subliminal Stimulation

• Below one’s absolute threshold for conscious awareness.

• Show clip

Does this work?Yes and No

•Slide studies showed some emotional reactivity (called priming a response).

•The effects are subtle and fleeting.

Sensory Adaptation

• Diminished sensitivity as a result of constant stimulation.

We do not perceive the world how it really is, but

as it is useful for us to perceive it.

Selective Attention• The focusing of conscious

awareness on a particular stimulus.

An example of selective attention is:

Cocktail Part Effect: ability to listen to one voice among many.

A Letter from College

Dear Mom,

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Dear Susan,

I kNOw that astroNOmy, ecoNOmics, and oceaNOgraphy are eNOugh to keep even an hoNOr student busy. Do NOt forget that the pursuit of kNOwledge is a NOble task, and you can never study eNOugh.

Love,

Mom

P.S. Thanks for your NOte!!