Sensation: Detection of stimuli
Perception: Interpretation, identification, and organization of sensory information
Sensation & Perception
Sensation: Detection of stimuli
The Senses
Vision LightHearing Sound wavesTouch Pressure, temperatureTaste ChemicalsSmell Chemicals
Balance GravityKinaethesia Movement
Proprioception Limb position
Sensation Bottom-Up Processing
analysis that begins with the sense receptors and works up to the brain’s integration of sensory information
reflects physical stimuli veridically (accurately)
•Absolute threshold - The minimum amount of energy our senses can consciously detect 50% of the time.– Vision – candle flame at 30 miles– Hearing – ticking watch at 20 feet– Taste – 1 tsp sugar in 1 gal water– Smell – 1 drop perfume through 3 rooms– Touch – bee wing falling on face at 1 cm
Sensation - Thresholds
Difference Threshold Also called “just noticeable difference” or JND
the smallest difference between two stimuli that is detectable 50 percent of the time
Smallest detectable difference between two stimuli
Adaptation & Habituation
Sensory adaptation - tendency of sensory receptors to fatigue and stop responding to an unchanging stimulus. This is a physical, bottom-up process
Habituation
Habituation - tendency of the brain to stop noticing constant, unchanging information. Example – your clothing, fan noise, perfume!
Psychophysics study of the relationship between physical characteristics of stimuli and our psychological experience of them
Light- brightness Sound- volume Pressure- weight Taste- sweetness
1. Perceptual cues are used 2. Perception is active, constructive3. Perceptual interpretations can be
wrong (illusions)4. Perception is affected by experience
Perception
Perception Top-Down Processing
information processing guided by higher-level mental processes
when we construct perceptions by drawing on our experience and expectations
Often imposes a meaning that does not exist in the physical stimulus (not veridical)
Top Down Processing• Aoccdrnig to a 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 porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.
• Amzanig huh?
Perceptual Organization
• Top- down process (individualized by experience)
• how your brain makes sense of the world, which includes “hiding” from you certain changes in stimuli so that the stimuli continue to appear constant to you
Gestalt Principles of Perception
Perception of Depth
• Images on the retina are 2-D• How do we perceive 3-D (depth)?
• CUE approach – we learn the connection between cues and depth through experience, yielding 3-D perceptions
Binocular Cues• Binocular cues - cues for perceiving depth based on both eyes.1.retinal disparity
images from the two eyes differ closer the object, the larger the disparity
2. convergence neuromuscular cue two eyes move inward (converge) more as objects get nearer
Monocular Cues• Monocular cues (pictorial
depth cues) – cues for perceiving depth based on one eye only.1.Linear perspective 2.Relative size 3.Interposition (overlap)
4.Texture gradient 5.Motion parallax Menu