2nd Nose You can use either hand, but this is the left hand, as seen from the back.]]Cross your middle finger behind your index finger. The index finger is sometimes called the pointer finger-- it's the finger right next to your thumb. The fingers should be touching near, but not at, the tips. It doesn't matter which hand you use.

Bring your crossed fingers to the tip of your nose Bring your crossed fingers to the tip of your nose. Place your fingers so that the tip of your nose is in the small space or gap between the two fingertips. If you're using your right hand, the right side of the tip of your middle finger and the left side of the tip of your index finger should be touching your nose; if you're using your left hand, this will be reversed. You will probably notice a strange sensation, as though you have two noses.

Run your crossed fingers slowly up and down the bridge of your nose Run your crossed fingers slowly up and down the bridge of your nose. If you haven't already felt the two-noses sensation, you likely will now, as your motor brain is tricked into thinking that each finger is focused on a separate nose.[2]

Chapter 6: Perception

Perception Selective Attention: the focus of conscious awareness on a particular stimulus.

Selective Attention The most famous example to illustrate selective attention is known as the “cocktail party effect.” http://www.huffingtonpost.com/2012/06/20/silent-gorilla-study- concentration-deaf_n_1612843.html?utm_hp_ref=science&icid=maing- grid7%7Cmain5%7Cdl5%7Csec1_lnk3%26pLid%3D171994

Testing Selective Attention – remember this activity?

http://www.echalk.co.uk/amusements/OpticalIllusions/motionBli ndness/motionBlindness.html Haircut http://www.youtube.com/watch?v=veD-BzCyHJc Brain Games color http://www.youtube.com/watch?v=JwdgjI4Dxng

Perception Visual Capture: refers to the tendency for vision to dominate the other senses.

Perceptual Organization Gestalt: an organized whole. Gestalt psychologists emphasize humans’ tendencies to integrate pieces of information into meaningful wholes. Things are not seen as sum of parts but immediately as wholes.

Top-down Processing You may start to see something in this picture if we give your brain some concepts to apply: “tree” “sidewalk” “dog” “Dalmatian” Click to reveal sidebar and hints one by one.

Gestalt

Perceptual Organization Figure-Ground Relationship: tendency to organize information into objects (figure) that stand out from their background(ground)

Figure Ground Relationship

Gestalt Psychology Grouping: the perceptual tendency to organize stimuli into coherent groups Grouping Principles: Proximity Similarity Continuity Closure Connectedness

Proximity: tendency to group nearby figures together

Similarity: tendency to group figures that are similar

Continuity: tendency to perceive continuous patterns

Closure: tendency to fill in the gaps in visual information.

Closure

Connectedness: spots, lines and areas are seen as unit when connected

Grouping examples

Which grouping principle do you see in this picture?

Illusionary Contours: We constantly filter information so it makes sense to us.

Depth Perception Depth Perception: the ability to see objects in three dimensions. Allows us to gauge distance. Visual Cliff: illustrated that crawling infants and newborns perceive depth.

Visual Cliff: A Test of Depth Perception Babies seem to develop this ability at crawling age. No animation. Instructor: as a preview of figuring out how we perceive depth, note that the pattern on the floor looks more condensed (and thus farther away) to the infant than the identical pattern on the table. The infant can perceive this difference as depth/height and see a danger of falling. Note that the ability to perceive glass as solid does not appear to be as innate as the fear of the cliff. Even newborn animals fear the perceived cliff.

Types of Depth Perception Binocular Cues: depth cues that rely on the use of two eyes. Examples of Binocular Cues: Retinal Disparity: idea that images of an object from the two eyes differ. The closer the object, the larger the difference (disparity.) Convergence: extent to which the eyes converge inward when looking at an object that brain keeps track of to measure distance.

Types of Depth Perception Monocular Cues: distance cues that are available to either eye alone. Often used in art.

Monocular Cue: Relative Size We intuitively know to interpret familiar objects (of known size) as farther away when they appear smaller. No animation.

Monocular Cue: Interposition Interposition: When one object appears to block the view of another, we assume that the blocking object is in a position between our eyes and the blocked object. No animation.

Monocular Cues: Relative Clarity Hazy object seems more distant

Monocular Cues: Texture Coarse = close Fine = distant

Monocular Cue: Relative Height We tend to perceive the higher part of a scene as farther away. This scene can look like layers of buildings, with the highest part of the picture as the sky. If we flip the picture, then the black part can seem like night sky… because it is now highest in the picture. Click to show bullets and example.

Monocular Cues: Relative Motion When we are moving, we can tell which objects are farther away because it takes longer to pass them. A picture of a moon on a sign would zip behind us, but the actual moon is too far for us to pass. No animation. A great animated example can be found at http://psych.hanover.edu/krantz/motionparallax/motionparallax.html. This depth perception cue is often referred to as motion parallax. It is used by many animals that don’t have the benefit of binocular cues because their eyes are on the sides of their heads. It is called “relative motion”; when we are moving, the objects we pass can appear to be moving in the opposite direction, and the farther objects don’t move as fast.

Motion Perception We perceive motion in many ways. Objects moving toward us We perceive this motion by watching the changing apparent size of an object. Objects moving to one side We perceive relative motion, although we often judge huge objects inaccurately. In what way? Why? Objects traveling in a more complex path, such as in an arc through the air coming toward us Baseball players, and even dogs, can run right to where a fly ball is going to land by keeping the ball in a constant apparent position in the sky. Click to reveal bullets. Instructor: an option for introducing this slide is connecting this concept to the relative motion monocular cue. The cues of relative motion that help us see distance can also be used in reverse; if we already know the size and thus the distance of objects, we can more accurately judge motion of ourselves or objects around us. First bullet: This is the growing/approaching Frisbee effect. Second bullet: We judge huge objects to be moving more slowly, perhaps because we are ready to judge them as closer, smaller objects covering less distance.

Monocular Cues: Linear Perspective and Interposition The flowers in the distance seem farther away because the rows converge. Our brain reads this as a sign of distance. No animation. Instructor: see if students can notice one other monocular cue for depth perception evident in this picture...interposition. The flowers in the very front (bottom of the frame) partially block the view of other flowers, and the whole hill of flowers appears to block the view of the hill in the background.

Tricks Using Linear Perspective These two red lines meet the retina as being the same size However, our perception of distance affects our perception of length. Click to bring bottom line up. The way our brain changes the perception of length in this case is called the Ponzo illusion, first demonstrated by Italian psychologist Mario Ponzo in 1913. The two [rods/bars/logs] are the same size on screen, but our eyes tend to see one as larger because linear perspective makes its location on the train tracks seem farther away.

Monocular Cues: Shading Effects – Relative Brightness Shading helps our perception of depth. Does the middle circle bulge out or curve inward? How about now? Click to invert the image and show the hollow as a hill.

Light and shadow create depth cues. No animation.

Monocular Cue?

Monocular Cue?

Monocular Cue?

What Cues Do You See?

How many Legs?

Perceptual Constancy color shape size Perceptual Constancy: perceiving objects as unchanging despite changes in retinal image color shape size

Shape Constancy What shape do you see outlined in red? No animation. Instructor: you could ask students an intentionally ambiguous question...“What shapes do you see outlined in red?” If they say “rectangle,” ask again, no longer referring to the doors. “Tell us the names of the red shapes.” Then click to fade the doors and reveal that the second and third red shapes are trapezoids.

Interplay Between Perceived Size and Distance Using monocular cues for distance can often cause us to perceive incorrect information.

Diameter of Circles Are the Same

Spelling test answers: CONTEXT EFFECT The text at the bottom of the screen will appear on click, and is mean to appear only AFTER you do the “spelling” test below. Instructor: The point of the test is to demonstrate how context, affected/primed by the previous word you stated, can affect which word they perceived. You can state to students, “Six word spelling test! You cannot ask questions; just take a guess and listen for the next word. Write these words down: Double. Pear. (Students may, if “double” gives them context, write “pair.”) Apple. Payor. (Students may, when primed by “apple”, write “pear.”) Payee. Pair. (Here, students might be confused, or some may write “payor.”) Spelling test answers: double pear apple payor payee pair Did context affect which word you wrote?

Muller-Lyer Illusion

Cultural Influences on Depth Perception

Impossible Image

Impossible Staircase

Warm Up http://www.youtube.com/watch?v=KApieSGlyBk

Sensory Deprivation and Perception Blind Person Example Some aspects of perception might be innate Others involve experiences Critical period for development of sensation and perception

Sensory Deprivation and Perception Kittens raised without exposure to horizontal lines later had difficulty perceiving horizontal bars.

Perceptual Adaptation (vision) ability to adjust to an artificially displaced visual field prism glasses

Perceptual Interpretation Perceptual Set: a mental predisposition to perceive one thing and not another. What you see in the middle is influenced by if you looked at bottom or the top

Lochness Monster or a Tree Trunk?

Perceptual Set Affects Other Senses Perceptual Set also affects other senses like audition. Ex: eel is on the wagon vs. eel is on the orange. CONTEXT MATTERS! Rat Man Lyrics

Perception and the Human Factor Human Factors Psychologists- explore how people and machines interact and how machines and environments can be adapted to human behaviors

Is there Extrasensory Perception? Extrasensory Perception: claim that perception can occur apart from sensory input. Astrological predictions, psychic healing, communication with the dead Telepathy- mind to mind Clairvoyance- perceiving remote events Precognition- perceiving future events Psychokinesis- mind over matter Example- light as a feather stiff as a board

Is there Extrasensory Perception? Parapsychology: study of paranormal phenomenon, including ESP and psycho kinesis. Research Psychics not accurate More predictions- police work Vague predictions Lottery No experiment has EVER produced a convincible demonstration of ESP

Phi Phenomenon Blinking lights give the illusion of motion