Introduction to Sensation

Transcription

1 Introduction to Sensation

2 Learning Targets 1. Contrast sensation & perception. 2. Distinguish between absolute and difference thresholds Explain Weber s Law

3 Sensation vs. Perception Sensation: our sensory Perception: The process of receptors and nervous system receive stimulus from the environment. Biological! organizing and interpreting sensory information, enabling us to recognize it as a meaningful object and/or events Cognitive

4 Bottom-Up Processing Your senses (through sensory receptors) send information to your brain

5 Top Down Processing information processing guided by higher-level mental processes (your brain)...we perceive life based on our experience and expectations -This cake tastes like coconut -That man could be a model.

6 Top-down v. bottom-up processing Bottom-up processing: senses take in info & relay it to our brain. Start at bottom (senses) work your way up -you examine each piece of the puzzle w/ your eyes... see the lines, shapes, colors & then make sense of it. Top-down processing: uses experiences & our memory to make sense of what we see,touch, taste, smell & hear -. your brain sees whole words rather than individual letters, you see someone with particular characteristics and stereotype - start at top (brain) We need top-down processing so we do not have to interpret everything in the world as new.

7

8 Bottom-Up vs. Top-Down Processing Bottom-Up: You rely on your EYES (senses) Top-Down: You rely on expectations & experiences

9 Transduction process of converting energy from the environment into neural impulses that can be understood by our brains receive-energy via specialized receptor cells transform- stimulation into neural impulse deliver-send impulse to brain

10 Sensation Each sense has specialized cells- sensory receptors Selective attention: the focusing of conscious awareness on a particular stimulus our senses take in 11 million bits of info per second your nose is in your line of vision can you feel your socks now?

11 Sensation: Cocktail Party Effect Cocktail party effect: your ability to attend to only one voice among many, but what happens when you hear your name?

12 Learning Targets 1. Contrast sensation & perception. 2. Distinguish between absolute and difference thresholds Explain Weber s Law

13 Thresholds Absolute Threshold: the minimum stimulation necessary to detect a particular youtube. com/watch? v=irewnzqyrpi light sound pressure taste odor... (50% of time...varies WITH AGE)

14 Signal Detection Theory Predicts how we detect a weak stimulus amid many other stimuli. detect sensations based on our experiences, motivations, expectations, degree of alertness, and fatigue level We new mom & dad driving taster *Assumes no absolute threshold

15 Phantom Cell Phone Vibration?!? 89% of the undergraduates in the study had experienced these phantom vibrations about every two weeks on the average although only one in 11 classified them as bothersome. Our body is always in waiting to anticipate any kind of technological interaction, which usually comes from a smartphone. With that anticipatory anxiety, if we get any neurological stimulation, our pants rubbing against our leg for example, you might interpret that through the veil of anxiety, as 'Oh, my phone is vibrating."

16 Subliminal stimulus that is below your absolute threshold or conscious awareness items so small that you aren t consciously aware that COULD prime your response later priming- mostly unconscious activation of certain associations that might predispose one s perception, memory or response

17

18 Difference Threshold Also called the JND (Just Noticeable Difference): The minimum difference that a person can detect between two stimuli. DIFFERENCE between A and B. *smallest difference in stimulus intensity that a specific sense can detect The point at which you notice there s a change TV volume Change in Stimulus

19 Weber s Law For difference to be noticed must be a constant percentage NOT constant amount

20 Quick Review

21 Sensory Adaptation Diminished sensitivity to a sense because of constant stimulation

22 Perceptual Set a mental predisposition to perceive one thing and not another seeing a police car TYPE car and perceiving a police car

23 context effects context plays an important role in how we perceive things. context (situation) creates a top-down processing because your expectations impact what you perceive

24 seeing someone from church at the store and not recognizing them because they are outside the context in which you usually interact

25

26 McGurk Effect