Sensory Perception

• Visual Cues


  Measures depth, form, motion, and constancy
• 2 Types of binocular vision: retinal disparity and convergence
• Retinal Disparity: the left and right fields of vision provide slightly different visual images when focusing on a single object
• Convergence


  a type of binocular disparity that causes the eyes to move closer together when the object is close. The eyes relax when the object is farther away.
• Binocular Vision


  Requires the use of both eyes
• Monocular cue


  required the use of one eye to see an effect
• Types of monocular cues: relative size, shading and contouring, relative motion, interposition, and relative height
• Relative size


  a visual cue that provides form. We perceive objects that are larger to be closer to us
• Interposition


  a visual cue that causes use to perceive that an object in front of the other is closer to use
• Relative height


  a visual cue that causes us to perceive that taller objects are further away from us and shorter objects are closer to us
• Relative motion/ motion parallax 


  perceiving that objects move faster when they are closer and slower when they are farther away
• 3 types of constancy: size, shape, and color
• Size constancy


  object of the same size may appear bigger or smaller when moved or turned a certain way
• Shape constancy


  object of the same shape may appear to be a different shape based on movment
• Color constancy


  object of the same color may appear lighter or darker based on movement
• sensory adaptation


  a change in sensitivity in your adaptation
• hearing adaptation


  accomplished by inner ear muscle contraction to dampen loud noises
• Touch adaptation


  nerves become desensitized and stop firing as frequently
• Smell adaptation

  olfactory nerve desensitivity
• Down regulatory sensory adaptations: hearing, smell, sight, touch, and proprioception
• down regulation in sight


  a change in rod and cone sensitivity, where the pupils constrict in the light
• up regulation in sight


  pupil dilation in a dark room
• Just Noticeable Difference (JND) 


  The threshold to difference in sensitivity
• weber's fraction

  $∆I/I=$$K$
• Weber's law Relationship

  linear
• Absolute Threshold

  the minimum intensity of a stimulus that's needed to detect a stimulus 50% of the time
• The absolute threshold is influenced by: expectations, experiences, motivation, alertness, and subliminals
• Types of somatosensation: thermoception, mechanoception, nociception, and proprioception
• Dermatomes


  allows the body to identify where the stimulus is coming from
• non adapting firing 


  equal spaces between action potentials
• slow-adapting


  neurons fire quickly before slowing down
• Fast-adapting


  neurons fire quickly before stopping then repeating this cycle
• Semicircular Canals


  provides spatial orientation due to endolymph that shifts based on our position
• Semicircular Canals: anterior, lateral, posterior
• Otolithic organ types: Utricle and saccule
• Otolithic organs


  detects linear acceleration and head positioning due to calcium crystals that are attached to hair cells.
• Dizziness and vertigo is caused by dysfunction in the vestibular system
• Dizziness


  endolymph does not stop moving when the body stops
• Bottom-up processing


  Processing based on data that starts with a stimulus to influence what we perceive
• Top-down processing


  processing based on theory, which used knowledge to influence preception