Perception

• Sensation - physical process of collecting data from the environment via the senses
• Perception - the cognitive process of interpreting sensory information that we receive
• What are the 2 types of Depth cues

  • Monocular depth cues
  • Binocular depth cues
• Monocular depth cues- cues that tell us approximately how far away something is using one eye
• What types of Monocular depth cues are there

  • Height of the plane
  • Relative size
  • Occlusion
  • Linear perspective
• Height of a plane - objects that are higher up in a visual field appear further away.
• Relative size - the more distant and object is , the smaller the image of that object will be in your visual field
• Occlusion - objects that are behind other objects are further away
• Linear perspective - lines that are parallel appear to get closer together and come to a point in the distance.
• Binocular depth cues - Cues that tell us precisely how far away something is using 2 eyes.
• What are the types of Binocular depth cues -

  • Retinal disparity
  • Convergence
• Retinal disparity - the concept that the left eye and the right eye view slightly different images.

  The size of the difference gives the brain information about the depth and distance.
• Convergence - the concept of how a an object closer to you makes your eye muscles work harder compared to something far away

  This gives the brain information about depth and distance.
• Binocular = binoculars so it uses 2 eyes
• Monocular = monocle so it is one eye
• Size constancy - even when the information received by our eye changes the size of the object, we understand that the object is still its original size
• Visual illustrations - when are visual perception is tricked into seeing something inaccurately
• Misinterpreted depth cues -

  • Ponzo illusion (rail way track)
  • Muller - lyer illusion (arrows)
• Ambiguity - when there are different interpretations of the same image the brain can't decide which interpretation to choose so it will flip

  • Necker cube (cube)
  • Rubin's vase ( cup vs 2 heads)
• Friction - the visual illusion where a person starts to see something in an image that isn't actually there

  Kanizsa triangle (fake triangle)
• Gibson direct theory of perception - he states that sensation and perception are actually the same thing
• The 3 main parts to Gibson's theory

  1. Optical flow patterns
  2. Motion parallax
  3. Influence of nature
• Optical flow patterns - when we are moving towards a fixed point , it stays stationary while the rest of our view seems to rush by
• Motion parallax - when we are moving, objects that are closer to us in our visual field appear to be moving faster than those that are further away from us.
• Influence of nature -

  We do not need to learn how to perceive the world around us.Are abilities are a innate
• Strengths to Gibson's theory

  • There is research to provide evidence to show that we don't need past experience to precieve the world around us (baby and cliff)
• Weakness of Gibson theory -

  • Visual illusions are perceptual errors, that our brain doesn't fix so we draw the wrong conclusion about what we are looking at. This shows that sensation and perception is different
• Gregory's constructivist theory of perception - he's state that we perceive based on our past experiences.
• What are the main parts of Gregory's theory -

  • Inference
  • Visual cues
• Inference - Its taking information in front of you and drawing a conclusion about what it means based on other things you know
• Visual cues - Usually our perception is accurate.However, sometimes the way we interpret things can be wrong. So the brain has help making inferences in thr form of visual cuse.
• Strengths of Gregory's theory

  • There is research that Supports his theory, Westerner Cultures don't fall for the Muller-tyer illusion saying both lines are the same length showing that perception links with past experiences
• Weakness of Gregory's theory

  • Visual Cliff experiment talks about babies refusing to crawl over a fake Cliff witch shows that perception must be innate
• Culture - Beliefs and expectations that surround us, we are influenced by our culture
• Hudson's theory 


  Culture
• Hudson's aim 


  To see if different cultures interpreted picture differently using depth cues
• Hudson's meathod

  He showed 2D images to people from different cultures and asked them 3 questions

  1. What do you see?
  2. What is the man doing?
  3. What is closer to the man?
• Hudson's results 


  White ppts were more likely to precieve depth than black ppts
• Hudson's conclusion 


  Culture plays a role in our perception
• Weakness of Hudson's theory 


  Ppts might not have understood instructions since researcher used translators