Changing the way you learn

Chapter Four

Psychophysics: How physical stimuli are translated into psychological experience
1. Threshold: Dividing point between energy levels that do or don't have a detectable effect
  1. Absolute threshold: Minimum amount of detectable stimulation
    1. Detected 50% of the time
  2. JND: smallest difference in amount of stimulation
    1. Weber's Law: Size of JND is constant proportion of size of initial stimulus
2. Signal-Detection Theory
  1. Detection of stimuli involves decision and sensory processes
  2. Influenced by noise and decision making strategies
3. Subliminal Perception: Registration of sensory input without conscious awareness
4. Sensory Adaption: Gradual decline in sensitivity due to prolonged stimulation
Visual System
1. Eyes
  1. Light enters through the CORNEA
  2. The CORNEA and LENS form upside-down image of objects onto RETINA
    1. Lens: Accomodation
      1. Curvature of lens adjusts to focus
        Close=Round lens Distant= Flat lens
        Nearsighted: Close objects are clear, distant are blurry Lens bends too much or eyeball is too long
        Farsighted: Distant objects seen clear, close objects blurry Eyeball is too short
    2. Retina: Absorbs light, processes images, sends visual info to brain
      1. Part of CNS
      2. Rods: Night vision and peripheral vision
        Density greatest just outside fovea
      3. Cones: Daylight and color vision
        Fovea: Tiny spot on retina that contains only cones
      4. Receptive field: Affects firing of cell
        Collection of rod and cone receptors
  3. IRIS controls amount of light that enters
  4. Saccades: Brief fixations essential to good vision
2. Light: Electromagnetic radiation
  1. Amplitude: Perception of brightness
  2. Wavelength: Perception of color
  3. Dark adaption: Eyes become more sensitive to light in low illumination
  4. Light adaption: Eyes become less sensitive to light in high illumination
3. Visual Pathway
  1. Optic Chaism: Optic nerves cross over and project to opposite sides of the brain
    1. Main Pathway: Thalmus + Primary Visual Cortex
    2. Second Pathway: Superior Colliculus + Thalmus Coordination of visual input with other sensory input
  2. Feature Detectors: Cells in visual cortex are specialized
    1. Ventral Stream: Details
    2. Dorsal Stream: Where objects are
    3. Visual Agnosia: Inability to recognize objects
    4. Prosopagnosia: Inability to recognize familiar faces
    5. Simple Cells: Line of certain width, position and angle
    6. Complex Cells: Lines in any position, moving in certain direction
4. Color Vision
  1. Subtractive color mixing: Removing wavelengths
  2. Addictive color mixing: Add more light
  3. Trichomatic Theory: Three types of receptors (red, blue, green)
  4. Complementary colors: Produce gray tones
  5. Afterimage: Image persists after stimulus is removed
  6. Opponent Process Theory: Depends on receptors to make opposite responses
    1. black/white, red/green, blue/yellow
Perceptual Processes
1. Reversible figures: Two interpretations that shift back and forth
2. Inattentional blindness: Concentrating on one thing, not noticing other things visually present
3. Bottom-up processing: Start as parts, build to whole
4. Top-down processing: whole to elements
5. Subjective Contours: Preseption of contours when they don't actually exist
6. Gestalt Principles: Whole is greater than sum of parts (Top-down)
  1. Phi phenomenon: Illusion of movement by rapid succession of visual stimuli
  2. Figure and Ground: Figure is object being looked at, ground is the background
  3. Proximity: Close together seem to belong together
  4. Closure: Group elements for completeness
  5. Similarity: Group stimuli that are similar
  6. Simplicity: Group elements to form a good figure
  7. Continuity: Follow direction they have been led in
7. Perceptual Hypothesis: Inference about which distal stimuli is responsible for proximal stimuli
  1. Distal: Distance from body
  2. Proximal: Affect sensory receptors
8. Binocular Cues: Clues about distance based on different views of both eyes
  1. Retinal Disparity: Images slightly different locations on both retinas
    1. Closer = more difference
  2. Convergence: Sensing eyes converging as they focus
9. Monocular Cues: Clues about distance based on image in either eye
  1. Motion Parallax: Images of different objects with different distances moving across retina at different speeds
  2. Pictorial Depth: Clues given in flat picture
  3. Perceptional Constancy: Stable perception in spite of changing sensory input
Auditory System
1. Sound Waves
  1. Wavelength: Pitch (Hz)
  2. Wave Amplitude: Loudness (dB)
  3. Wave Purity: Timbre
2. The Ear
  1. Outer Ear: Sound is constructed by vibration of molecules
    1. Pina (sound collecting cone) funnels sound waves into auditory canal and then ear drum
  2. Middle ear: Sound constructed by vibration of bones
    1. Hammer, anvil, and stirrup (OSSICLES) amplify changes in air pressure
  3. Inner Ear: Sound constructed by waves in fluid and sent to brain
    1. Inside the cochlea is the basilar membrane which holds auditory receptors (hair cells) which are stimulated by waves of fluid
    2. Neutral signals are sent to thalamus to auditory cortex
3. Theories
  1. Place Theory
    1. Preception of pitch corresponds to vibration of different places on basilar membrane
  2. Frequency Theory
    1. Perception of pitch corresponds to rate that basilar membrane vibrates
  3. Both correct - Hairs vibrate together as vibrations move along membrane
Chemical Senses
1. Gustatory System: Taste
  1. Chemicals dissolved in saliva (stimuli) on taste buds (receptors) send impulse to thalamus
  2. Primary tastes: sweet,sour,bitter,salty
  3. Supertasters: 4 times as many taste buds
    1. More likely in women
    2. Less fond of sweets, vegetables, alcohol
2. Olfactory: Smell
  1. Olfactory cilia (receptors) have axons that synapse with olfactory bulb at base of brain
Touch
1. Pressure (tactile stimulation): Receptive field with center surround arrangement with excitatory center and inhibitory surround or the opposite
  1. Nerve fibres carry messages to spinal cord and brain stem and cross to opposite side of brain
    1. Pass through thalamus to somatosensory cortex in parietal lobe
2. Pain
  1. Fast pathway: Myelinated neurons and registers localized pain in seconds
  2. Slow pathway: Unmyelinated neurons about less localized, longer pain
  3. Cognitive and emotional processes are able to block signals from skin receptors
3. Gate Control Theory: Incoming pain sensations pass through process in spinal cord that can be closed by skin/brain receptor signals
  1. Endorphins responsible for suppression of pain
  2. Glial cells may decrease pain
Other Systems
1. Kinesthetic System: Monitors position of various parts of the body
2. Vestibular System: Responds to gravity (balance)
  1. Semicircular canals (inner ear) - Fluid changes and is detected by hair cells

Next up

Chapter Four

Description

Resource summary

Media attachments

Similar

	Created by Mackenzie Fabbro almost 9 years ago