Slide 1: TOK - Perception An introductionSlide 2: ‘He who has been bitten by a snake fears a piece of string’ Persian proverbSlide 3: A fool sees not the same tree as a wise man sees. William Blake People only see what they are prepared to see. Ralph Waldo Emerson Were the eye not attuned to the Sun, the Sun could never be seen by it. Goethe A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral. Saint – Exupery Observers are not led by the same physical evidence to the same picture of the universe unless their linguistic backgrounds are similar or can in some way be calibrated. Benjamin Whorf Slide 4: Slide 5: The Epistemological Divide  The scientific investigation into the nature of biological vision has been plagued by a persistent confusion over a central philosophical issue, which is the question of whether the world we see around us in visual consciousness is the real world itself, or whether it is merely a perceptual replica of that world in an internal representation.Slide 6: Supporting the role of perception - Direct Perception  Some people would say that it is not a form of thinking, in that one's ideas do not affect the process. Perception is automatic and independent of will. In this view perception is viewed as objective.   Direct Realism Theory of perception according which we perceive material objects directly, without the mediation of ideas or sensory representations. Although it is also called "naïve" realism, this view often requires a sophisticated defense, especially in its attempts to account for the occurrence of hallucinations and perceptual error.Slide 7: Challenging the reliability of perception Indirect Perception  Idealism Belief that only mental entities are real, so that physical things exist only in the sense that they are perceived.   Representationalism Theory of perception according to which we are aware of objects only through the mediation of the ideas that represent them. Helps explain illusions but leads to debate about the   Phenomenonalism Belief that the immediate objects of sensation provide no evidence for the existence of anything beyond themselves. Physical objects have no reality apart from our individual, private perceptual experiences of them.Slide 8:  “Out of mind” by Paul Brooks  Synopsis: “Our eyes are limited tools, and we compensate by dreaming up most of the world. We see much less than we imagine, and we imagine much more than we see.”  Most of the time, like most people, I live in a world of make-believe. It’s not just that I read fiction and watch films. There are many other occasions on which I disengage from online perception of the outer world and enter a private, inner space. In the course of an ordinary day I will conjure a thousand scenes from memory, recent and remote, rehearse a hundred imaginary conversations, and project dozens of fleeting sexual fantasies onto my mental movie screen. I am constantly reading other people’s minds, simulating their feelings, decoding their attitudes and intentions. I project images of myself into near and distant futures, and often extrapolate to an uncertain, curiously thrilling, point of non- existence. Sometimes I just daydream.  But what sense does it mean to speak of “inner” and “outer”? In truth, there is no sharp distinction between reality and imagination. Or, rather, there is no clear dividing line between perceptions of the real, solid world “out there” and the shifting, insubstantial realm of mental life. They both draw on the same cognitive resources, which are built into the same brain circuits – visual imagery is coded in the synapses of the visual system, imagined sounds activate the auditory cortex. The real wonder is that we know the difference. And the vibrant, detailed picture of the world that seems to fill our waking hours is a sham. The perceptual psychologist Alva Noë calls it the “grand illusion”. Far from being uniform, panoramic, high-resolution, colour-rich and continuous – as the visual world appears to be – the information supplied to the brain from the eyes is actually sparse, disjointed and largely monochrome. The brain confabulates a world from two tiny, upside-down retinal images, which constantly change as the eyes saccade from one point to another three or four times every second – snapshot, blackout, snapshot, blackout. We see much less than we imagine, and imagine much more than we see.Slide 9: Optical IllusionsSlide 10: Slide 11: Slide 12: Slide 13: Slide 14: Slide 15: Slide 16: Slide 17: Slide 18: Slide 19: Slide 20: Slide 21: Stare at the black dot for a minute (the longer the better), and watch the colored 'fluff' disappear! Slide 22: Close your left and eye and just focus your right eye on the tiny cross. At some point the big circle will disappear as it crosses your 'blind spot'. If you can't see this effect, then try sitting closer/further from the screen.                                                                                         Slide 23: Slide 24: Slide 25: Slide 26: Slide 27: Slide 28: Slide 29: Slide 30: Slide 31: Slide 32: Slide 33: Slide 34: Slide 35: Slide 36: Slide 37: Slide 38: Slide 39: Slide 40: Slide 41: Slide 42: Slide 43: Slide 44: Slide 45: Slide 46: Slide 47: Slide 48: Slide 49: Slide 50: Slide 51: Slide 52: Slide 53: Slide 54: Slide 55: Perception - Using our senses Empiricism – the theory that all knowledge is derived from sense- experienceSlide 56: What our senses can perceive:- SIGHT 1% of the electromagnetic spectrum. (We sense radio waves as sound, infrared as heat, ultraviolet, X-rays and gamma rays as damage to our cells). SOUND Frequencies between 16 and 20,000 Hz.Slide 57: TOUCH Varies according to the sensitivity of different parts of our bodies.Two points are perceived as distinct at a distance of 1mm on our tongues, and 70mm on our backs. SMELL Molecules that are soluble in our nasal mucus. TASTE A slight sweetness is better perceived using the tip of the tongue.Slide 58: red? How reliable are our senses? • What is d? Is it the same to all of us? • What influences how reliable they are? • Which sense is the most reliable? • How do we know whether we have the right interpretation of our senses? • Has the use of ICT blurred the differences between simulation and reality?Slide 59: Slide 60: How many ‘F’s? Finished files are the result of years of scientific study combined with the experience of many yearsSlide 61: Perceiving words Liddle Mees Muffitt Saa Tonner Tufford Eaton Herr Corzon Waye Winn Alongo Kammer Spyra Unda Sathe Don Beese Eidher Ann Frydmann Mies Muffitt Taw WaySlide 62: Little Miss Muffitt Sat on a tuffett Eating her curds and whey When along came a spider And sat down beside her And frightened Miss Muffitt awaySlide 63: Optical illusions in art have not only been created in modern times. The next picture is by Guiseppe Arcimboldo, an Italian painter of the 16th century. Perceiving picturesSlide 64: M. C. Escher Mosaic II, 1957Slide 65: M.C.Escher Day and night, 1938Slide 66: Young woman/old woman? First published in Puck in 1915, entitled ‘My wife and my mother-in-law’Slide 67: What can you see here?Slide 68: Slide 69: Slide 70: Slide 71: What influences perception? •Attention (we cannot process everything that reaches our senses) • Convention and cultural aspects (e.g. right angles, perspective) •Belief/language (to what extent do we perceive what is incongruent to our past experiences?) •Expectations (familiar sights)Slide 72: To organize sense perceptions in our brains we require, at the very least, the following learned factors: • inference • concepts • experience • context • interpretationSlide 73: closeSlide 74: Slide 75: Now look at the following websites.  http://cns-alumni.bu.edu/~slehar/cartoonepist/cartoonepist.html  http://members.aol.com/Ryanbut/illusion1.html  http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html  http://www.grand-illusions.com/triangle.htm  http://www.skytopia.com/project/illusion/illusion.html  http://www.ritsumei.ac.jp/~akitaoka/index-e.html  http://www.artlex.com/ArtLex/o/opticalillusion.html  http://www.rebfile.com/Rebhanwriting/bubblesofperceptiontext.htm  http://www.optical-illusionist.com/anim1-1.shtml Produce a one 2 sided collection of your favorite pieces and add them to your TOK notes.Slide 76: