Perception - AP Psych

• David Hubel and Torsten Wiesel discovered neurons in the visual system called feature detectors, which are neurons that focus on edges, lines, angles, curves, and movements
• Simple cells: cells responding specifically to certain lines

  Complex cells: cells responding to motions
• Impulses run from the optic nerve to the thalamus to the visual cortex.
• Brains can only pay attention to one thing at a time. Divided Attention is what is commonly perceived as multitasking, but it is really when we are focusing on two things at once.

  Focus Attention is when you home in on a specific stimuli, and we hop from stimulus to stimulus.
• Cocktail party effect: if we hear our name or something else we find important, we will be distracted from our current focused stimuli to focus on that
• Selective Inattention: when you "hear what you want to hear"; you screen out unwanted stimuli because of anxiety / unwanted feelings / unimportance
• Inattentional blindness: the tendency to overlook something when your attention is elsewhere

  Change blindness: type of inattentional blindness; the inability to see changes in the environment if focus is centered on something else
• Perception: the mental process of organizing sensory input into meaningful patterns

  What we sense is not always what we perceive
• Stroop Effect: identifying color that is printed in incongruent colors
• Habituation is a type of adaptation where hearing is still sensed and sent to the brain, but not to the cortex for processing
• Selective adaptation happens when you no longer send the stimuli you are receiving during sight, smell, taste, and touch to get processed because you have gotten used to it
• Binocular cues: visual information taken in by two eyes to judge depth perception

  • Retinal disparity: left and right fields of vision provide slightly different visual images
  • Convergence: how far inward the eyes have to focus on an object
• Stroboscopic movement: the movement of a series of images that suggests movement. We perceive movement in slightly varying images shown in rapid successsion
• Phi Phenomenon: an illusion of movement that arises when stationary objects are placed side by side and illuminated rapidly one after another
• Perceptual constancy is our ability and need to perceive objects as unchanging even if changes do occur

  Color constancy: the perception that the color of an object remains if lighting conditions change

  Size constancy: tendency to perceive objects as the same apparent size regardless of their distance from us.

  Shape constancy: our knowledge of the shape stays the same even if angle changes

  Light constancy: the white, gray, and black of objects stay the same in different lights
• Perceptual set: perceive one aspect of a thing and not another (top - down mental processing)

  Schemas: mental filters or maps that organize our information about the world

  Bottom up processing: Perceptions are built from sensory input

  Context and Culture effect: Tendency or bias to perceive some stimuli and not others is influenced by our expectations, emotions, motivation and culture (emotional context affecting perception)
• Parapsychology: (NOT REAL SCIENCE) claims that people have perceptual abilities outside of the realm of existing scientific laws

  ESP / Extrasensory Perceptions: perception without specific sensory input

  • astrology
  • palm reading
  • Telepathy: mind reading
  • Clairvoyance: speak with the dead
  • Precognition: telling the future
  • Psychokinesis: moving objects with mind
• Gestalt Psychology: we see the whole; the brain's tendency to integrate pieces of information into meaningful wholes

  Figure to ground: we can see both images, but one (figure) is clear and one (ground) is blurry
• Illusionary figure: mind creating something that doesn't exist
• Monocular cues: depth perception with use of one eye

  • Linear perspective: parallel lines converging in distance
  • Interposition: blocked objects are farther than the blocking objects
  • Relative Size: smaller objects are father if there are larger objects of assumed similar size
  • Relative Height: objects higher on canvas appear farther
  • Relative Clarity: clear objects are closer than blurry
  • Light and Shadow: nearer objects reflect more light
  • Texture gradient: closer objects have more detailed textures
  • Motion parallax: closer objects appear to move faster
• Relative motion: when we are moving, stationary objects around us seem to move opposite of us
• Muller-Lyer Illusion

  
• Ponzo Illusion

  
• Moon Illusion: The moon looks larger to us when it's closer to the horizon than when its farther up in the sky
• Depth Perception: the ability to see the world in 3d and judge how far certain objects are from you