A Show of Hands

1. A Show of Hands • Remove all rings and bracelets from your right hand. • Try to identify your hand. • How did you form your hypothesis about which copy was yours and which ones were not? What types of evidence were involved in your choice? • What types of perception were involved in your choice? • What does this exercise suggest about the knowledge gained from perception? How reliable is it? • Is something more than knowledge necessary for knowledge to be gained?

2. Sense Perception • If for some reason you had to sacrifice one of your five senses, which would you be most willing to lose, and which would you be least willing to lose? • Most people say they would be most willing to lose their sense of smell and least willing to lose their sight. • This is in large part because we have become a visually oriented society that often associates knowledge with sight.

3. Sense Perception • In the most general of definitions, sense perception is the physical response of our senses to stimuli. Our senses include hearing, taste, touch, smell, and sight, for which we have sense receptors in different parts of our bodies. We also have internal physical receptors for awareness of our own bodily sensations, such as hunger, pain, and arousal. • Today the study of sense perception is largely the domain of psychology. In a very simplified fashion, the process of sense perception is three-fold. First, our sense receptors are stimulated by sensory information. The brain then translates that sensory information into sensations such as sound, taste, temperature, pressure, smell, or sight, for example. Finally, higher centres in the brain either ignore or recognize the sensations and their meanings, based on neuronal networks of past association and expectation. • We do not sense all the stimuli that we're potentially able to sense. There's too much going on in our environment for us to handle, and we unconsciously ignore many stimuli.

4. Perception as the Search for Meaning • One of the axioms of perception is that we assume that the human mind involuntarily creates meaning from stimuli. • This is an activity that goes on in spite of your will or desire. • Perception, however, is not objective and unlearned; it is context and culturally dependent and directed towards making sense of the world. • Complete the exercise on page 46 • In contrast to this exercise, have you ever seen a movie where you recognize an actor but can seem to place who they are?

5. Sense Perception as an Active Process • According to common sense realism, perception is passive and a relatively straight forward process giving us an accurate picture of reality. • But there is more to perception than meets the eye, and it is active process not a passive one. • Rather than just relying on what’s ‘out there’ our perception is affected by the structure of our sense organs and our minds. • Watch: “How The Human Eye Works” • Complete Reuben Abel Reading with questions

6. Interpreting Our World • Although it seems easy for us to perceive the world, perception is actually a very complex process. • Our perception is broken down into: • Sensation – what we perceive in the world • Interpretation – what our minds do with it • Read: Visual Agnosia: A World Without Patterns, Faces Without Meaning by Hillary Lawson • Watch: My Strange Brain and At First Sight • We usually are not aware of how we interpret the world, we just experience the world of our perceptions, but maybe by looking at the world of perceptual illusions we can help to move beyond sensations and examine our interpretations.

7. Organizing Our World • The mind organizes things the following way: • Attraction of a stimulus – you pay attention • Differentiation of stimulus – a figure versus a background relationship • Focus on stimulus – the details of the thing • Naming the stimulus – closure • What are some examples of things we would like quick closure in our perception and renewable closure?

8. The Gestalt Principle • Gestaltists find that the mind perceives the simplest possible form but also that it tends to see the best or most correct possible form. • This means that we tend to see things not as they really are but as our minds think they should be. We make mental corrections all the time. • The fact that our brain interpret new stimuli based on past experience is critical to our being able to use perception as a way of knowing.

11. We perceive whole configurations not parts. As you read, you read words not letters.

12. Look at the chart and say the colour NOT the word

13. Inattentional Blindness • Watch: The Awareness Test • Read the quote by Alva Noe • ...consider the following familiar sort of gag. I say to you as you tuck into your lunch: ‘Hey isn’t that Mick Jagger over there?’ You turn around to look. When you do, I snatch one of your French fries. When you turn back you’re none the wiser. You don’t remember the exact number or layout of fries on your plate and you weren’t paying attention when the fry was snatched. Your attention was directed elsewhere. • It turns out that this sort of failure to notice change is a pervasive feature of our visual lives. Usually when changes occur before us, we notice them because our attention is grabbed by the flickers of movement associated with the change. But if we are prevented from noticing the flicker of movement when the change occurs, we may fail to notice the change. What is striking – and this will become important later on – is the fact that we will frequently fail to notice changes even when the changes are fully open to view. Even when we are looking right at the change when it occurs, something we can test with eye trackers, we may fail to see the change.

14. Inattentional Blindness • Perception is attention dependent. You only see that to which you attend. • The video clip you watched was an example of inattentional blindness • Changes that affect the meaning of any scene are more likely to be noticed; other changes are ignored • Our brain does not build up detailed internal models of the scene even though we think this is the case

15. Additional Thoughts about Perception and Meaning • So we don’t notice things. Maybe that isn’t the purpose of perception. For example, study of visual perception reveals that perceptual processes are not structured to record data but to organize meaning. • And maybe this isn’t a weakness at all. Image if we had to record and maintain all data as separate fragments; we would become paralysed from dealing with a chaos of inputs with nothing connected to anything else. • The miracle of the mind is that it copes so well with a jumble of inputs and is able to organize sense data so that most of the time your world is reasonable coherent, predictable and stable.

16. Making sense of the disorderly array of stimuli that constantly bombard us • We filter out much of what reaches us. We only pay attention to certain things. We stop paying close attention to something as soon as it becomes familiar, or as soon as we can classify it with a word. • We rely on memory to ‘fill in the gaps’. This capacity is beneficial to our individual and collective survival. • If we had to process all the stimuli that reach our sense organs all the time, our brains would be too busy to become aware of the...

17. HUGE GRIZZLY BEAR STALKING US!!!!!!

18. Making sense of the disorderly array of stimuli that constantly bombard us • Head out into the hallways of the school. As you walk around, try to empty your mind of everything you’ve ever learned about your environment. Try to react immediately to everything solely with your sense perceptions, without classifying or judging anything. • Look at a door and don’t think ‘door’, enter a classroom and don’t think ‘classroom’, let only your senses react to your classmates and teacher. Put food in your mouth and don’t identify the food, classify its taste with a word or think of its nutritional value. • What would the world be like if we only relied on our sense perceptions? • How do we make sense out of our world? • Complete the description of the teacher activity.

19. Selectivity of Perception • What we perceive out of all the ‘sense noise’ of the environment depends on a host of factors about the object of perception, the person who is perceiving, and the context in which the perception is taking place. • Many factors influence what we perceive and remember: out of all possible sense observations that we might make, we catch only a few, and out of all that we might remember, we recall even fewer. Perception is a selective process.

20. Selectivity of Perception • Apart from visual illusions, another reason for being cautious about what our senses tell us is that perception is selective • A vast amount of data is constantly flooding in to our senses, and our minds would overload if we were consciously aware of everything • So we only notice some things in our perceptual field and overlook others • Certain aspects of a situation engage our attention and ‘stand out’, and the rest fade away into a more or less indeterminate background

21. Selectivity of Perception • If we ask what kind of stimuli we usually notice, intensity and contrast are two important factors • A ticking clock may go unheard, but a bomb exploding in the next classroom would • What you see also depends on various subjective factors such as interest and mood • Your interest can be thought of as filters which determines what shows up as you scan the world around you • As the pattern of our interest changes, so does what we perceive

22. Selectivity of Perception • When your family buys a new car, you might notice the same brand of car everywhere • When a woman becomes pregnant, she often begins noticing pregnant woman wherever she goes • Our feelings and emotions also effect our perceptions – when you are in a good mood, you see the world in a different way to when you are in a bad mood • An emotion such as love can have a strong effect on perception

23. Selectivity of Perception • When in love with someone, you may unconsciously project your dreams onto them so that they seem to possess every quality you desire • And, when you fall out of love with someone, you may look at your ‘ex’ and wonder what you ever saw in them • It has been said that in the beginning of a relationship, you tend to notice the things you have in common, and at the end of a relationship we tend to notice the things that make us different

24. The Impact of Culture on Perception • Complete The Allegory of the Cave/The Matrix activity • Complete the Culture Simulation Game

25. Perception, Conception and the Influence of Culture • Do all of the students pictured here perceive cows and bulls in a similar way? • Yes, they all use their senses and believe they do so within the normal range. • Their sense perceptions of the animals are similar, but their conceptions – shaped by prior learning including cultural practices and beliefs – differ considerable.

27. We Perceive Things or People Differently Based on the Name Depending on the name given to those in this photo, what would be the chance of someone investing in their company? Imagine they were called : The Young Inventors, The Geeks from the Blue or Microsoft Executives. What would be your interpretation of the photo without a caption? This is a picture of the Microsoft Executive in 1978...Bill Gates is in the lower left corner.

28. The Myth of the Mental Instant Replay • We think of visual perception as operating like a television camera, recording the full details of a scene on a tape that is labelled and filed in the brain. • Several studies demonstrate that our ability to recall is shockingly vulnerable to manipulation by emotion, social stresses and position or the way a question is asked among other factors. • Complete Perception and Multiple Perspectives Exercise • You will be given a card. On it, you will find a witness or a person connected to the following event involving a car accident. • Consider the various perspectives and the various meaning that each perspective brings to the interpretation of the event. • What kinds of questions would you ask of those involved? What would you expect to be asked?

30. Distinguishing Appearance from Reality • The fallibility of perception has implications in the real world as well • In criminal trials, juries tend to put a great deal of faith in eye-witness testimonies, and this evidence can be a major factor in determining if someone is guilty or innocent • However, according to psychologists, the uncorroborated evidence of a single witness should be treated with great caution – and many instances of criminal convictions based on eye witness testimony have turned out to be false

31. Distinguishing Appearance from Reality • Although perception is an important source of knowledge, our distinction has shown there are at least three reasons for treating it with caution: • We may misinterpret what wee see • We may fail to notice something • We may misremember what we have seen • However, we should not be overly sceptical and never trust our senses, we need a way to distinguish appearance from reality • Confirmation by another sense: is one way to do this – for example, if something looks like an apple, and tastes like an apple – then it is reasonable to assume it is an apple

32. Distinguishing Appearance from Reality • Coherence: is another way to distinguish appearance from reality • If what you see doesn’t ‘fit in’ with your overall experience of the world, then you might be mistaken • If you were drinking and saw a pig flying over some rooftops, you might be unlikely to believe the next day in what you saw because your experience has shown that pigs lack the aerodynamic abilities to fly – so you will dismiss what you ‘saw’ as an alcohol induced hallucination • Coherence also explains that the pencil was not bent due to our experience with pencils

33. What is Really Out There? • If our eyes had evolved differently, and we were sensitive to light at a different wavelength we would not see white in the snow at all • We must conclude that their in no color in the world at all – reality is colorless • The tree in the forest: is a well known question “if a tree falls in the forest and there is no one around to hear it – does it make a sound?” – the common answer is yes, of course it makes a sound! • One way to resolve this is to classify two types of sound: • Physical sound – the air molecules vibrating into waves of sound • Experienced sound – the actual crash and bang we hear when the tree hits the ground

34. What is Really Out There? • In another example, when you drink coke, it tastes sweet • Does the sweetness exist in the coke, or in your mouth? • Again it is a subjective experience that results from the coke and your taste buds • While it may be easy to accept that taste and pain are subjective experiences, it might be harder to grasp this about things like colors • Surely, the sky is blue and snow is white? • But if we apply the same logic, we are forced to admit that the white is no more in the snow as the sweetness was in the coke • The white we see is the interaction of our eye mechanics to the wavelengths of light reflected by the snow

35. Theories of Reality • There are three different theories about the relationship between perception and reality: • Common-sense realism: is the common-sense idea, that the way we perceive the world mirrors the way the world is • However, since what we perceive is determined in part by the nature of our sense organs, we have seen that there is good reasons for rejecting common-sense realism • Scientific realism: in which the world exists as an independent reality, but is very different from the way we perceive it

36. Theories of Reality • In scientific realism, a table is mostly emptiness, sparsely scattered in the emptiness are electric charges rushing around with great speed • The scientific descriptions of atoms whizzing around in space seems a far cry from the colors, odours, and sights of the world • Phenomenalism: the philosophical position known as empiricism – and this leads to the more extreme position of phenomenalism • According to this view, matter is simply the permanent possibility of sensation and it makes no sense to say the world exists independent of our experience of it

37. Theories of Reality • Using our table analogy, a phenomenalist would say that if you go into our classroom you would have ‘table experiences’ • Phenomenalism follows the logic that all knowledge must ultimately be based on experience • It says that we cannot know what the world is independent of our experience of it – the point is beyond our experience of reality, there is nothing to be said • It is a somewhat humble position, for it insists we know the world from our distinctly human perspective and have no right to pontificate about the nature of ultimate reality

38. What Should We Believe? • The three theories of reality can be summarised as: • Common-sense realism – “You see is what is there” • Scientific realism – “Atoms in the void” • Phenomenalism – “To be is to be perceived” • What is interesting is that if you push imperialism to its limits – you come up with counter-intuitive conclusions • So we choose empiricism and insist we know nothing about ultimate reality or reject empiricism and insist there is a world independent of our experience of it • Most people tend to be realists about the world, despite its doubts

39. What Should We Believe? • So to conclude, perception is an important way of knowing and plays a key role in most areas of knowledge • However, as we have seen through the unit, there is more to perception than ‘meets the eye’ • We cannot just take our sense evidence for granted as our senses can deceive us, they can be selective, and distorted by our beliefs, prejudges, and emotions • So perception cannot give us certainty, but as we have previously discussed, knowledge requires less than certainty • If perceptual evidence is consistent with other ways of knowing like reason, then it is a good foundation for reliable knowledge