Chapter 6 – Sensation and Perception

 

I.  Sensation vs. Perception

       A.  Sensation:  detecting some physical stimulus

       B.  Perception:  how we know what our senses register

 

II.  Psychophysics (psychological experience of physical stimulus)

       A.  Absolute threshold

       B.  Difference threshold (or JND)

      

III.  Dealing with Sensory Input

       A.  Sensory adaptation

       B.  Selective attention

              1.  “cocktail party effect”

 

IV.  Vision

       A.  Visual stimuli:  lightwaves

              1.  wavelength à hue

              2.  amplitude à brightness

              3.  complexity à saturation

       B.  Structure of the eye

              1.  rods vs. cones; fovea vs. periphery

 

FOVEA

PERIPHERY

Lots of cones

Few cones

No rods

Lots of rods

Good acuity

Poor acuity

Poor sensitivity to dim light

Good sensitivity to dim light

Day (color) vision

Night (achromatic) vision

 

              2.  Other structures of the eye

       C.  Visual Perception

1.  The importance of FORM

2.  Gestalt principles in recognizing form

       a.  figure vs. ground

                     b.  proximity

                     c.  closure

                     d.  similarity

                     e.  continuity

              2.  Depth/distance perception

                     a.  binocular cues

i.  convergence

ii.  retinal disparity

                     b.  monocular cues

                           i.  linear perspective

                           ii.  interposition

                           iii.  relative size

                           iv.  texture gradients

              3.  Perceptual constancy

                     a.  shape, location (stability), size, brightness, color

              4.  Visual illusions

                     a.  the importance of context in everyday vision

 

V.  Hearing

       A.  Auditory stimuli:  soundwaves

              1.  wavelength (frequency) à pitch

              2.  amplitude à loudness

              3.  complexity à timbre

       B.  Structure of the ear

 

Soundwave à eardrumàvibrates 3 inner ear bonesà vibrate to oval windowà

vibrates fluid in cochleaàauditory nerve

 

VI.  Taste (Gustation)

       A.  basic tastes:  sour, bitter, sweet, salty (and umami?)

       B.  determined by which fibers (inside taste buds) are stimulated, and in what proportions

       C.  tastes also influenced by experience/exposure, cultural preferences, smell, and individual differences in tasting ability (e.g., “supertasters”)

 

VII.  Smell (Olfaction)

       A.  gaseous molecules fit into receptors in olfactory epithelium

 

VIII.  Touch (skin sensations)

       A.  basic touch sensations:  pressure, warmth, cold, pain

 

IX.  Kinesthesis and equilibrium

       A.  kinesthesis:  where we and our body parts are in space

              1.  input from muscles, tendons, joints

       B.  equilibrium:  sense of balance

              1.  input from semicircular canals in inner ear