attention and perception guide

• Sensory receptors


  Collect information
• Sensory processes


  Process information reaching the brain
• Motor systems


  Process information going out of the brain to muscles and glands
• Difference threshold


  Smallest difference between two stimuli that can be consistently and accurately detected on 50% of trials
• Our sensation is affected by our past experiences and expectations
• Absolute threshold


  Minimum amount of physical energy needed to produce a sensory experience
• Vision


  1. Eye gathers and focuses light

  2. Image formed on retina

  3. White light passes through prism separates into visible spectrum
• Colorblindness


  Partial or total inability to distinguish colours
• Hearing


  1. Sound created when actions cause objects to vibrate

  2. Frequency refers to number of cycles a wave completes in a given time

  3. Pitch is highness or lowness of sound determined by frequency

  4. Loudness is physical intensity of sound determined by amplitude

  5. Timbre is quality of sound wave's complexity

  
• Sensation


  Stage where neural activity codes information about nature of stimulation
• Perception


  • Stage where internal representation of an object is formed
  • Elaboration and interpretation of sensory experiences
  • Synthesis of simple sensory features into percept of an object
• Perceptual organization


  Figure ground organization - sensations grouped into objects/figures on a plainer background
• Perceptual constancy


  • Perception of an object's shape, size or brightness remains the same even though its image on the retina has changed
• Size constancy


  Perceived size of an object remains the same even though the size of its image on the retina changes
• Shape constancy


  Shape of an object remains stable even though the shape of its retina image changes
• Brightness constancy


  Brightness of objects appears to stay the same as lighting conditions change
• Depth perception


  Ability to see three-dimensional space and accurately judge distances
• Depth perception cues


  • Monocular cues (work with one eye)
  • Binocular cues (require two eyes)
• Binocular cues


  Most basic source of depth perception caused by retinal disparity (discrepancy in images reaching right and left eyes)
• Pictorial cues


  Features in paintings, drawings and photographs that impart information about space, depth and distance
• Illusions


  Distorted perception of stimuli that exist
• Hallucinations


  Perception of objects or events that have no external reality
• Selective attention


  Process of giving priority to a particular incoming sensory message
• Functions of attention


  • Acts as sensory filter
  • Facilitates response selection
  • Gateway to consciousness
• Determinants of attention


  • Physical factors (repetition, contrast, shape, size, brightness)
  • Motives
• Extra Sensory Perception (ESP)


  Ability to perceive objects or events in ways that cannot be explained by known sensory capacities
• Types of ESP


  • Clairvoyance (perceiving events/information unaffected by distance or barriers)
  • Telepathy (perception of another person's thoughts)
  • Pre-cognition (ability to accurately predict future events)
  • Psycho-kinesis (ability to influence inanimate objects by will-power)
• Eyewitness testimony


  Key to decisions in the judiciary but prone to distortion
• Perceptual awareness and positive psychology


  Humanistic psychologists believe some people perceive themselves and others with unusual accuracy
• Perceptual clarity requires rigorous effort of paying more and more attention
• Breaking perceptual habits and interrupting habituation can lead to good results
• Perception is influenced by past experiences, memory and expectations
• Colour perception is possible due to cone cells in the fovea