Sensation and Perception Running Document.docx - Sensation...

Sensation and Perception
3.Or
Why Study Sensation & Perception? 8/27/19
Academically, perception is…
 Fundamental to behavior, learning, cognition, socializing, etc.
 At the interface of Psychology, Biology, and Philosophy
Practically considered, studying perception is
 To know what’s out there
 To get around
 To create works of art
 For medical diagnostics
 For military operations
 For marketing
 To imagine what other animals perceive
Sensation : receiving and representing energy
Perception : organizing and interpreting information
Sensation
 Energy must be transduced
 Convert energy from one form to another
 E.g., speaker, microphone, rods & cones
 Requires energy
Transduction happens in the eye, but perception happens in the brain.
Perception
 Requires information
 External: Patterns of energy that are linked to the physical world (light, sound pressure,
etc.)
 Internal: Relative to previous experience (expectation/ knowledge)
Sensory Systems
 Vision
 Audition (hearing)
 Olfaction (smell)

 Taste
 Touch
 Vestibular (head)
 Kinesthesia (body sense)
 Heat
 Pain
 And maybe others… (itch?)
Helmholtz’ 3 Ps (1800s)
 P hysics- energy & the physical world
 P hysiology- Neural processing, specialized parts of the brain decode different
components of an image: color, motion, form, depth.
 P sychology- cognition & behavior
*********Specialized parts of the brain decode different components of the image.
Leibowitz Gets P ractical
 Symbiosis between theoretical research and practical research
o E.g., From hamsters to highways (soon)
Today: 2 of Helmholtz’s 3 P’s
1. P hysics- energy & the Physical world
2. P hysiology- neural processing
3.(& some psychoanalytic too)
 Stimulus for vision= light
 Leibowitz’ Law of vision
- Most fundamental law of vision
- “You can’t see a damn thing in the dark!”
- Meanwhile… you can’t hear a damn thing on the moon”
The electromagnetic spectrum
Different species are sensitive to different wavelengths
Human eye Bee Eye sensitive to (UV)

2 Ways of Thinking about Light
1. Illumination
 Energy that left a source and arrived on a surface.
 Measured (in lux) by placing a sensor on a surface
 potential information
2. Luminance
 light after it reflects off a surface

Measured (in candelas/ m
2
) by pointing sensory in a direction
 Information
9/3/2019
2 Key themes of this course
1. Yes, perception supports action. But action feeds perception too!
 We see so that we can act
 But we act so that we can see too
 Obvious example: Eye movements
2.Our physiology determines our experience of the world. (And our experiences
determine our physiology!)
Ex 1: Mistaking someone to be a hat
Ex 2: Brain’s wiring changing due to practicing music
Agnosia
 Inability to recognize objects
 typically caused by lesions in parietal and temporal lobes
 sensation without perception?