Test your Awareness 1 (basketball game)

Core Concepts in Understanding Sensation and Perception AP Unit 3 Reading pp

I CAN Distinguish sensation vs. perception Apply Weber’s Law/Fetchner’s Law Apply transduction, adaptation and threshold to the senses

S and P S- the process by which we gain (sense) information from the outside world –occurs through receptor cells- specialized cells, which carry energy message to neuron P- occurs after S; the way our brain mentally assigns meaning to the raw material we sensed- influenced by individual expectation

Core Concept (p111) Klingemanized Our sense organs (ears, eyes, etc) are the vehicle which transports stimuli from the world to our BRAIN. –Our BRAIN does the sensing So, what we see, hear, etc… is our brains NEURAL REPRESENTATION of what actually exists –Color blindness, deafness, etc

All Senses share these 3 Characteristics 1.Transduction- ability to convert physical energy (ex: sound waves) into a neural transmission 1.Once stimulated nerve impulses travel along sensory pathways to processing area of cortex 2.Adaptation- responsiveness to sensations lessens over time (thalamus stops ranking it as important) 3.Thresholds- study of is called psychophysics; determined by the least amount of energy you can detect at least ½ the time

Absolute Thresholds Taste: 1 gram (.0356 ounce) of table salt in 500 liters (529 quarts) of water Smell: 1 drop of perfume diffused throughout a three-room apartment Touch: the wing of a bee falling on your cheek from a height of 1cm (.39 inch) Hearing: the tick of a watch from 6 meters (20 feet) in very quiet conditions Vision: a candle flame seen from 50km (30 miles) on a clear, dark night

Stimulation  Transduction  Sensation  Perception

Difference Threshold/ Just Noticeable Difference What is the smallest difference in stimuli, where you can notice a difference- (think TV volume)

Difference Threshold Difference Threshold: Minimum difference between two stimuli required for detection 50% of the time, also called just noticeable difference (JND). Difference Threshold Tell when you (observer) detect a difference in the light. No Observer’s Response NoYes

Weber’s Law Change in intensity of stimulus=constant Applied: Bob lifts 10 lb weights and his JND is 2 additional lbs. If Bob lifts 100 lbs, his JND is going to be 20 lbs –This means the JND is large(takes more difference) when the stimulus intensity is high and small (takes little difference) when intensity is low Book Experiment

EX: Bob’s jnd when initially carrying 10 pounds is 1 pound. Weber’s law states that if Bob was carrying 100 pounds initially, his jnd will be 10 pounds.

Fechner’s Law and Steven’s Law Deal with real and perceived magnitude of stimulus Say the same thing, but Steven’s accounts for more senses- pain and temperature –EX: Susie is listening to the radio, when she 1 st turns it on, she adjusts the volume a little and it make a BIG difference. After listening for a while, she changes the volume by the same degree, but barely notices a difference.

Signal Detection Theory (SDT) Predicts how and when we detect the presence of a faint stimulus (signal) amid background noise (other stimulation). SDT assumes that there is no single absolute threshold and detection depends on: Person’s experience Expectations Motivation Level of fatigue Carol Lee/ Tony Stone Images Fight Club- our detection of “clips” the 1 st time we see it is far LESS then subsequent viewings Implication: we can “turn up or down” our ability to detect the presence of stimuli

No Detection Intensity Absolute Threshold Detected Yes No Observer’s Response Tell when you (the observer) detect the light.

Test your Awareness 2

Subliminal Messages Subliminal- below the threshold –Subliminal Priming- shown/told (good EX on p117) No proof that this can influence a mass audience or that tapes played while sleep can make you quit smoking; however, evidence indicates a positive correlation between exposure to SM and achieving desired outcome

Friends: Quit Smoking

Can I? Distinguish sensation vs. perception Apply Weber’s Law/Fetchner’s Law Apply transduction, adaptation and threshold to the senses