Sensation and Perception The Basics Chapter 4 Section 1

What is Sensation Stimulation of sensory receptors and the transmission of sensory information to the central nervous system. What we see, taste, feel, smell and hear.

What is Perception The psychological process through which we interpret sensory stimulation. Making sense of what we see, taste, feel, smell and hear.

As each slide scrolls, write a brief description about each picture. ZOOM ART As each slide scrolls, write a brief description about each picture.

Think about it! How did your perception of the picture change as you viewed more and more of it? Compare your first evaluation and your last evaluation. How different are they?

http://www.exploratorium.edu/exhibits/mona/mona.mpg Brick wall Rutgers

Absolute Thresholds the weakest amount of stimuli that can be sensed Examples the number of hairs on the back of one's hand that must be touched before it can be felt the faintest sound that a person can hear

Some Examples Vision – A candle flame viewed from a distance of about 30 miles on a dark night. Hearing – The ticking of a watch from about 20 feet away in a quiet room. Taste – About 1 teaspoon of sugar dissolved in 2 gallons of water.

Difference Threshold the minimum amount of difference between two stimuli Example The difference between paint samples The difference between one increase in volume on a stereo v. two increases

Why is Absolute threshold and difference threshold so important? So we can detect stimuli without being overwhelmed So we can differentiate between stimuli

THINK ABOUT IT! Why is it important to differentiate between stimuli?

Signal detection theory Method of distinguishing sensory stimuli that takes into account elements such as the setting, your physical state, your mood and attitudes Examples Hearing a friend in a crowded room Having a cold (food will taste different) Feeling angry or upset (may change your reaction) Motivation, expectations and learning can all play roles in signal detection

Sensory Adaptation We become more sensitive to weak stimuli Example Eyes adjust to darkness We become less sensitive to unchanging stimuli On the beach as time passes we are less aware of the sound of the ocean

Looking Forward In what ways can a better understanding of how you sense and perceive information add to your understandings of behavior?