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Psychology · Perception

Illusion Lab

Find your blind spot, make colours that are not there, shrink a person in an Ames room and find out how much your brain guesses.

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First lesson01 · Sensation or perception?See all 28 lessons →

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The course

7 worlds · 28 lessons

World 1 · Your Brain Builds the World

FREESensation, perception, the blind spot and the tricks of brightness
  1. 01Sensation or perception?Your brain's two jobs · 8 min
  2. 02Find your blind spotThe hole in your vision · 10 min
  3. 03Filling in, and the moments you are blindGaps the brain hides · 9 min
  4. 04Brightness is not what it seemsSame pixels, different greys · 10 min

World 2 · Colours That Are Not There

PROThree cones, opposing colours, the dress and colour-vision differences
  1. 01Three cones, millions of coloursWhy a screen can make yellow from red and green · 10 minPRO
  2. 02Afterimages and opponent coloursColours that appear after you look away · 10 minPRO
  3. 03Colour constancy and the dressThe brain subtracts the lighting · 9 minPRO
  4. 04When colour vision differsMany ways to see colour · 9 minPRO

World 3 · Two Eyes, One Depth

PROStereo vision, one-eye cues, parallax and 3D screens
  1. 01Stereo visionTwo views, one depth · 10 minPRO
  2. 02Depth cues with one eyeHow artists fake depth on flat paper · 9 minPRO
  3. 03Motion parallax and perspectiveDepth from moving · 9 minPRO
  4. 04Depth on a flat screen3D films and VR · 9 minPRO

World 4 · The Room That Shrinks People

PROSize constancy, the Ames room, context illusions and expectation
  1. 01Size constancyWhy people do not shrink as they walk away · 9 minPRO
  2. 02The Ames roomA room built to fool one eye · 10 minPRO
  3. 03Ponzo and Müller-LyerIllusions that survive being explained · 9 minPRO
  4. 04Expectation: hollow masks and faces everywhereTop-down perception · 9 minPRO

World 5 · Impossible Objects and Ambiguous Pictures

PROGestalt grouping, two-way pictures, the Penrose triangle and edges that are not there
  1. 01Gestalt: the whole before the partsHow the brain groups things · 9 minPRO
  2. 02Figure and ground: Rubin and NeckerOne picture, two readings · 8 minPRO
  3. 03The Penrose triangleAn impossible object you can build · 10 minPRO
  4. 04Illusory contoursEdges that are not there · 8 minPRO

World 6 · Time, Motion and Attention

PROReaction time, apparent motion, the invisible gorilla and the cost of multitasking
  1. 01How fast are you?Reaction time and a falling ruler · 10 minPRO
  2. 02Apparent motion and the waterfall effectMotion that is not there · 9 minPRO
  3. 03Did you see the gorilla?Inattentional blindness · 9 minPRO
  4. 04Change blindness and multitaskingWhat you miss when you look away · 10 minPRO

World 7 · When Senses Disagree

PROHearing lips, owning a rubber hand, throwing your voice and measuring "just noticeable"
  1. 01The McGurk effectSeeing a sound · 9 minPRO
  2. 02The rubber handWhen a fake hand feels like yours · 9 minPRO
  3. 03Ventriloquism and timingWhy the voice seems to come from the puppet · 9 minPRO
  4. 04How different is different?Weber's law · 10 minPRO
Illusion Lab — interactive 3D lab · Novareka