Chapter 6 : Sensation and Perception

Frequency

the number of complete wavelengths that pass a point in a given time (for example, per second). determines the pitch

Figure-Ground

the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground). (p. 235)

Tinnitus

a phantom sound; ringing in the ear sensation

Subliminal

below one's absolute threshold for conscious awareness. The stimuli you cannot detect 50 percent of the time. (Below your absolute threshold)

Anosmia

unable to smell

In terms of perception, a band's lead singer would be considered _______ (figure/ground), and the other musicians would be considered _______ (figure/ground).

Figure; Ground

Cats are also able to open their ______ much wider than we can, which allows more light into their eyes so they can see better at night.

Pupils

Fovea

the central focal point in the retina, around which the eye's cones cluster. Many have their own hotline to the brain: Each one transmits to a single bipolar cell that helps relay the cone's individual message to the visual cortex, which devotes a large area to input from the fovea. These direct connections preserve the cones' precise information, making them better able to detect fine detail.

Masking Stimulus

that interrupts the brain's processing before conscious perception

Priming

the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response.

Cones

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

Prosopagnosia

facial blindness (recognition)

Eardrum

A tight membrane causing sound waves to vibrate

Psychokinesis

"mind over matter," such as levitating a table or influencing the roll of a die.

Parallel Processing

( doing many things at once) To analyze a visual scene, the brain divides it into subdimensions—color, motion, form, depth—and works on each aspect simultaneously. We then construct our perceptions by integrating the separate but parallel work of these different visual teams. the processing of many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision. Contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving. Studies of patients with brain damage suggest that the brain delegates the work of processing color, motion, form, and depth to different areas. After taking a scene apart, the brain integrates these subdimensions into the perceived image. How does the brain do this? The answer to this question is the Holy Grail of vision research.

Gestalt

( german meaning for a " form" or a "whole) an organized whole. Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes. (ex Necker Cube) (to organize our sensations into perceptons)

What three factors will make it more likely that you correctly detect a text message?

(1) You are expecting a text message. (2) It is important that you see the text message and respond. (3) You are alert.

ESP (Extrasensory Perception)

(Perception without Sensation) the controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition. telepathy: mind-to-mind communication. clairvoyance: perceiving remote events, such as a house on fire in another state. precognition: perceiving future events, such as an unexpected death in the next month.

The Physical Properties of Waves

(a) Waves vary in wavelength (the distance between successive peaks). Frequency, the number of complete wavelengths that can pass a point in a given time, depends on the wavelength. The shorter the wavelength, the higher the frequency. (b) Waves also vary in amplitude (the height from peak to trough). Wave amplitude determines the intensity of colors.

Touch sensations

(pressure, warmth, cold, and pain): Stroking adjacent pressure spots creates a tickle. Repeated gentle stroking of a pain spot creates an itching sensation. Touching adjacent cold and pressure spots triggers a sense of wetness, which you can experience by touching dry, cold metal. Stimulating nearby cold and warm spots produces the sensation of hot (Figure 6.38 on the right).

Stroboscopic

A phenomenon when the brain also perceives continuous movement in a rapid series of slightly varying images (a phenomenon called stroboscopic movement). As film animation artists know well, you can create this illusion by flashing 24 still pictures a second. The motion we then see in popular action adventures is not in the film, which merely presents a superfast slide show.

Sematosensory cortex activation

A self-produced tickle produces less somatosensory cortex activation than does the same tickle from something or someone else (Blakemore et al., 1998). (The brain is wise enough to be most sensitive to unexpected stimulation.)

Illustrate, using sound, the distinctions among these concepts: absolute thresholds, subliminal stimulation, and difference thresholds.

Absolute threshold is the minimum stimulation needed to detect a particular sound (such as an approaching bike on the sidewalk behind us) 50 percent of the time. Subliminal stimulation happens when, without our awareness, our sensory system processes that sound (when it is below our absolute threshold). A difference threshold is the minimum difference for us to distinguish between two sounds.

McGurk Effect

But what do you suppose happens if we see a speaker saying one syllable while we hear another? Surprise: We may perceive a third syllable that blends both inputs. Seeing the mouth movements for ga while hearing ba we may perceive da—a phenomenon known as the McGurk effect, after its discoverers, psychologist Harry McGurk and his assistant John MacDonald

What do we mean when we say that, in perception, the whole is greater than the sum of its parts?

Gestalt psychologists used this saying to describe our perceptual tendency to organize clusters of sensations into meaningful forms or coherent groups.

Context Effects

Imagine hearing a noise interrupted by the words "eel is on the wagon." Likely, you would actually perceive the first word as wheel. Given "eel is on the orange," you would hear peel. This curious phenomenon, discovered by Richard Warren, suggests that the brain can work backward in time to allow a later stimulus to determine how we perceive an earlier one. The context creates an expectation that, top-down, influences our perception

Face Recognition Processing

In social animals such as humans, a dedicated brain system (shown here in a left-facing brain) assigns considerable neural bandwidth to the crucial task of face recognition.

Does perceptual set involve bottom-up or top-down processing? Why?

It involves top-down processing. Our perceptual set influences our interpretation of stimuli based on our experiences, assumptions, and expectations.

Cornea

Light enters the eye through the cornea, which protects the eye and bends light to provide focus

What is the rapid sequence of events that occurs when you see and recognize a friend?

Light waves reflect off the person and travel into your eye, where the receptor cells in your retina convert the light waves' energy into neural impulses sent to your brain. Your brain processes the subdimensions of this visual input—including depth, movement, and form—separately but simultaneously. It interprets this information based on previously stored information and your expectations into a conscious perception of your friend.

Binocular Cues

depth cues, such as retinal disparity, that depend on the use of two eyes. Judging the distance of nearby objects.

Volley Principle

Like soldiers who alternate firing so that some can shoot while others reload, neural cells can alternate firing. By firing in rapid succession, they can achieve a combined frequency above 1000 waves per second Best explains some combination of place and frequency seems to handle the pitches in the intermediate range.

The Telltale Brain

Looking at faces, houses, and chairs activates different brain areas in this right-facing brain.

The amplitude of a sound wave determines our perception of ______ (loudness/pitch).

Loudness

Color- deficient vision

Most people with color-deficient vision are not actually "colorblind." They simply lack functioning red— or green—sensitive cones, or sometimes both. Their vision—perhaps unknown to them, because their lifelong vision seems normal—is monochromatic (one-color) or dichromatic (two-color) instead of trichromatic, making it impossible to distinguish the red and green in Figure 6.21 (Boynton, 1979). Dogs, too, lack receptors for the wavelengths of red, giving them only limited, dichromatic color vision (Neitz et al., 1989). But how is it that people blind to red and green can often still see yellow?

The amplitude of sound waves

determines their loudnesss

The Jumpy Eye

Our gaze jumps from one spot to another every third of a second or so, as eye-tracking equipment illustrated in this photograph of Edinburgh's Princes Street Gardens (Henderson, 2007). The circles represent fixations, and the numbers indicate the time of fixation in milliseconds (300 milliseconds = three-tenths of a second).

What is the field of study that researches claims of extrasensory perception (ESP)?

Parapsychology

Which theory of pitch perception would best explain a symphony audience's enjoyment of the high-pitched piccolo? How about the low-pitched cello?

Place Theory; Frequency Theory

Some nocturnal animals, such as toads, mice, rats, and bats, have impressive night vision thanks to having many more _______ (rods/cones) than _______ (rods/cones) in their retinas. These creatures probably have very poor _______ (color/black and white) vision.

Rods; Cones; Color

What is the rough distinction between sensation and perception?

Sensation is the bottom-up process by which the physical sensory system receives and represents stimuli. Perception is the top-down mental process of organizing and interpreting sensory input.

Blindsight

Shown a series of sticks, they report seeing nothing. Yet when asked to guess whether the sticks are vertical or horizontal, their visual intuition typically offers the correct response. When told, "You got them all right," they are astounded. There is, it seems, a second "mind"—a parallel processing system—operating unseen. These separate visual systems for perception and action illustrate dual processing—the two-track mind.

Where are vestibular sense receptors located?

The Inner Ear

What are two key theories of color vision? Are they contradictory or complementary? Explain.

The Young-Helmholtz trichromatic theory shows that the retina contains color receptors for red, green, and blue. The opponent-process theory shows that we have opponent-process cells in the retina for red-green, yellow-blue, and white-black. These theories are complementary and outline the two stages of color vision: (1) The retina's receptors for red, green, and blue respond to different color stimuli. (2) The receptors' signals are then processed by the opponent-process cells on their way to the visual cortex in the brain.

There are no receptor cells where the optic nerve leaves the eye (see Figure 6.14 above). This creates a blind spot in your vision. To demonstrate, first close your left eye, look at the spot, and move the page to a distance from your face at which one of the cars disappears (which one do you predict it will be?). Repeat with the other eye closed—and note that now the other car disappears. Can you explain why?

The blind spot does not normally impair your vision, because your eyes are moving and because one eye catches what the other misses. Your blind spot is on the nose side of each retina, which means that objects to your right may fall onto the right eye's blind spot. Objects to your left may fall on the left eye's blind spot.

What are the basic steps in transforming sound waves into perceived sound?

The outer ear collects sound waves, which are translated into mechanical waves by the middle ear and turned into fluid waves in the inner ear. The auditory nerve then translates the energy into electrical waves and sends them to the brain, which perceives and interprets the sound.

Why is it that after wearing shoes for a while, you cease to notice them (until questions like this draw your attention back to them)?

The shoes provide constant stimulation. Sensory adaptation allows us to focus on changing stimuli.

Hearing-test -tone

To test your absolute threshold for sounds, a hearing specialist would expose each of your ears to varying sound levels. For each tone, the test would define where half the time you could detect the sound and half the time you could not. That 50-50 point would define your absolute threshold.

How do we normally perceive depth?

We are normally able to perceive depth thanks to the binocular cues that are based on our retinal disparity, and monocular cues including relative height, relative size, interposition, linear perspective, light and shadow, and relative motion.

How does our system for sensing smell differ from our sensory systems for vision, touch, and taste?

We have two types of retinal receptors, four basic touch senses, and five taste sensations. But we have no basic smell receptors. Instead, different combinations of odor receptors send messages to the brain, enabling us to recognize some 10,000 different smells.

The Wavelengths we see

What we see as light is only a tiny slice of a wide spectrum of electromagnetic energy, which ranges from gamma rays as short as the diameter of an atom to radio waves over a mile long. The wavelengths visible to the human eye (shown enlarged) extend from the shorter waves of blue-violet light to the longer waves of red light.

Transduction

conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret. (p. 218)

Monocular Cues

depth cues, such as interposition and linear perspective, available to either eye alone. For distance

Retinal Disparity

a binocular cue for perceiving depth: By comparing images from the retinas in the two eyes, the brain computes distance—the greater the disparity (difference) between the two images, the closer the object. Try it. Hold your two index fingers, with the tips about half an inch apart, directly in front of your nose, and your retinas will receive quite different views. If you close one eye and then the other, you can see the difference. (You may also create a finger sausage, as in Figure 6.27.) At a greater distance—say, when you hold your fingers at arm's length—the disparity is smaller. We could easily build this feature into our video-computer system. Movie makers can simulate or exaggerate retinal disparity by filming a scene with two cameras placed a few inches apart. Viewers then wear glasses that allow the left eye to see only the image from the left camera, and the right eye to see only the image from the right camera. The resulting 3D effect, as Avatar movie fans will recall, mimics or exaggerates normal retinal disparity. Similarly, twin cameras in airplanes can take photos of terrain for integration into 3D maps.

Cochlea

a coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses

Cochlear Implant

a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea. (p. 246)

Visual Cliff

a laboratory device for testing depth perception in infants and young animals.

Perceptual Set

a mental predisposition to perceive one thing and not another. a set of mental tendencies and assumptions that greatly affects (top-down) what we perceive. Perceptual set can influence what we hear, taste, feel, and see.

Iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening. It dilates and constricts in response to light intensity and even to inner emotions.

Signal Detection Theory

a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness.

Pitch

a tone's experienced highness or lowness; depends on frequency. Long waves have low frequency—and low pitch. Short waves have high frequency—and high pitch

Phi Phenomenon

an illusion of movement created when two or more adjacent lights blink on and off in quick succession. When two adjacent stationary lights blink on and off in quick succession, we perceive a single light moving back and forth between them. Lighted signs exploit this phi phenomenon with a succession of lights that creates the impression of, say, a moving arrow.

Bottom - Up Processing

analysis that begins with the sensory receptors and works up to the brain's integration of sensory information. ( starts at the sensory receptors and works up to higher levels of processing.) Sensation is the bottom-up process by which the physical sensory system receives and represents stimuli.

Kinesthesis

the system for sensing the position and movement of individual body parts.

Sensory Adaptation

diminished sensitivity as a consequence of constant stimulation. they adapt to what's constant and detect only change. Benefit: Freedom to focus on informative changes in our environment without being distracted by background chatter We perceive the world not exactly as it is, but as it is useful for us to perceive it. Cuts, edits, zooms, pans, sudden noises—all demand attention.

Vast Visual Encyclopedia

distributed as specialized cells (Perrett et al., 1988, 1992, 1994). These cells respond to one type of stimulus, such as a specific gaze, head angle, posture, or body movement. Other supercell clusters integrate this information and fire only when the cues collectively indicate the direction of someone's attention and approach. This instant analysis, which aided our ancestors' survival, also helps a soccer goalie anticipate the direction of an impending kick, and a driver anticipate a pedestrian's next movement.

Sensorineural Hearing Loss

hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves; also called nerve deafness. Occasionally, disease causes sensorineural hearing loss, but more often the culprits are biological changes linked with heredity, aging, and prolonged exposure to ear-splitting noise or music.

Conduction Hearing Loss

hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.

Place Theory

in hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated. Best explains how we sense high pitch. High frequencies produced large vibrations near the beginning of the cochlea's membrane, low frequencies near the end. But a problem remains: Place theory can explain how we hear high-pitched sounds but not low-pitched sounds. The neural signals generated by low-pitched sounds are not so neatly localized on the basilar membrane.

Frequency Theory

in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch. Best explains how we sense low pitch The whole basilar membrane vibrates with the incoming sound wave, triggering neural impulses to the brain at the same rate as the sound wave. If the sound wave has a frequency of 100 waves per second, then 100 pulses per second travel up the auditory nerve. But again, a problem remains: An individual neuron cannot fire faster than 1000 times per second. How, then, can we sense sounds with frequencies above 1000 waves per second (roughly the upper third of a piano keyboard)?

Embodied Cognition

in psychological science, the influence of bodily sensations, gestures, and other states on cognitive preferences and judgments. illustrate how brain circuits that process our bodily sensations connect with brain circuits responsible for cognition. After holding a warm drink rather than a cold one, people are more likely to rate someone more warmly, feel closer to them, and behave more generously (IJzerman & Semin, 2009; Williams & Bargh, 2008). Physical warmth promotes social warmth. After being given the cold shoulder by others in an experiment, people judge the room as colder than do those treated warmly (Zhong & Leonardelli, 2008). Social exclusion literally feels cold. Holding a heavy rather than light clipboard makes job candidates seem more important. Holding rough objects makes social interactions seem more difficult (Ackerman et al., 2010). When leaning to the left—by sitting in a left-rather than right-leaning chair, squeezing a hand-grip with the left hand, or using a mouse with their left hand—people lean more left in their expressed political attitudes (Oppenheimer & Trail, 2010).

Perceptual Adaptation

in vision, the ability to adjust to an artificially displaced or even inverted visual field.

Top - Down Processing

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations. ( constructs perceptions from the sensory input by drawing on our experience and expectations.) Perception is the top-down mental process of organizing and interpreting sensory input.

The longer the sound waves are, the ______ (lower/higher) their frequency is and the ______ (higher/lower) their pitch.

lower; lower

Decibels

measuring sound in Decibels represents the absolute threshold for hearing. Every 10 decibels correspond to a tenfold increase in sound intensity. Thus, normal conversation (60 decibels) is 10,000 times more intense than a 20-decibel whisper. And a temporarily tolerable 100-decibel passing subway train is 10 billion times more intense than the faintest detectable sound.

Feature Detectors

nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement. Feature detector cells derive their name from their ability to respond to a scene's specific features—to particular edges, lines, angles, and movements. These cells pass this information to other cortical areas, where teams of cells (supercell clusters) respond to more complex patterns. As we noted earlier, one temporal lobe area by your right ear (Figure 6.17) enables you to perceive faces and, thanks to a specialized neural network, to recognize them from varied viewpoints. If this region were damaged, you might recognize other forms and objects, but, like Heather Sellers, not familiar faces. When researchers temporarily disrupt the brain's face-processing areas with magnetic pulses, people are unable to recognize faces. They will, however, be able to recognize houses, because the brain's face-perception occurs separately from its object-perception

Color Constancy

perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.

Perceptual Constancy

perceiving objects as unchanging (having consistent shapes, size, brightness, and color) even as illumination and retinal images change.

Supercell Clusters

respond to more complex patterns. They Integrate this information and fire only when the cues collectively indicate the direction of someone's attention and approach. This instant analysis, which aided our ancestors' survival, also helps a soccer goalie anticipate the direction of an impending kick, and a driver anticipate a pedestrian's next movement.

Rods

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond. Rods have no such hotline; they share bipolar cells with other rods, sending combined messages. typically takes 20 minutes or more before your eyes fully adapt in the dark.

Depth Perception

the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance.

Pupil

the adjustable opening in the center of the eye through which light enters.

Intensity

the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amplitude (height). (p. 227)

The middle Ear

the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window.

Hue

the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth.

Wavelenght

the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission.

Inner Ear

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs. (p

Retina

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

Difference Threshold

the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference (or jnd). That difference threshold increases with the size of the stimulus. Thus, if you add 1 ounce to a 10-ounce weight, you will detect the difference; add 1 ounce to a 100-ounce weight and you probably will not.

Absolute Thresholds

the minimum stimulation needed to detect a particular stimulus 50 percent of the time. (is the intensity at which a person can detect a stimulus half the time. Hearing tests locate these thresholds for various frequency levels.) At or slightly below this threshold, we will still detect the stimulus some of the time.

Optic Nerve

the nerve that carries neural impulses from the eye to the brain.

Grouping

the perceptual tendency to organize stimuli into coherent groups. Having discriminated figure from ground, we (and our video-computer system) must also organize the figure into a meaningful form. Proximity : We group nearby figures together. We see not six separate lines, but three sets of two lines. Continuity: We perceive smooth, continuous patterns rather than discontinuous ones. This pattern could be a series of alternating semicircles, but we perceive it as two continuous lines—one wavy, one straight. Closure : We fill in gaps to create a complete, whole object. Thus we assume that the circles on the left are complete but partially blocked by the (illusory) triangle. Add nothing more than little line segments to close off the circles and your brain stops constructing a triangle.

Blind Spot

the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there.

Sensory Interaction

the principle that one sense may influence another, as when the smell of food influences its taste. Smell plus texture plus tase equals flavor. The eyes guides the ear.

Weber's Law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum (proportion) percentage ( NOT a constant amount). (p. 221) Two lights, for example, must differ in intensity by 8 percent. Two objects must differ in weight by 2 percent. And two tones must differ in frequency by only 0.3 percent

Sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Accommodation-2

the process by which the eye's lens changes shape to focus near or far objects on the retina.

Perception

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events. (the processes by which her brain organizes and interprets sensory input)

Vestibular Sense

the sense of body movement and position, including the sense of balance. The biological gyroscopes for this sense of equilibrium are in your inner ear. The semicircular canals, which look like a three-dimensional pretzel (Figure 6.35a), and the vestibular sacs, which connect the canals with the cochlea, contain fluid that moves when your head rotates or tilts. This movement stimulates hairlike receptors, which send messages to the cerebellum at the back of the brain, thus enabling you to sense your body position and to maintain your balance.

Audition

the sense or act of hearing

Parapsychology

the study of paranormal phenomena, including ESP and psychokinesis.

Psychophysics

the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them. (p. 218)

Opponent - process Theory

the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green. Hering, a physiologist, found a clue in afterimages. Stare at a green square for a while and then look at a white sheet of paper, and you will see red, green's opponent color. Stare at a yellow square and its opponent color, blue, will appear on the white paper. (To experience this, try the flag demonstration in Figure 6.22.) Hering surmised that there must be two additional color processes, one responsible for red-versus-green perception, and one for blue-versus-yellow.

Young-Helmholtz Trichromatic (three-color) Theory

the theory that the retina contains three different color receptors—one most sensitive to red, one to green, one to blue—which, when stimulated in combination, can produce the perception of any color.

Gate - control Theory

the theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain. The "gate" is opened by the activity of pain signals traveling up small nerve fibers (that conducts most pain signals) and is closed by activity in larger fibers ( that conduct most other sensory signals) or by information coming from the brain. The spinal cord contains small nerve fibers that conduct most pain signals, and larger fibers that conduct most other sensory signals. Melzack and Wall theorized that the spinal cord contains a neurological "gate." When tissue is injured, the small fibers activate and open the gate, and you feel pain. Large-fiber activity closes the gate, blocking pain signals and preventing them from reaching the brain. Thus, one way to treat chronic pain is to stimulate (by massage, electric stimulation, or acupuncture) "gate-closing" activity in the large neural fibers

Lens

the transparent structure behind the pupil that changes shape to help focus images on the retina.

Umami

they encountered a receptor for what we now know is a fifth—the savory meaty taste of umami, best experienced as the flavor enhancer monosodium glutamate.

Synaesthesia

where one sort of sensation (such as hearing sound) produces another (such as seeing color). Thus, hearing music or seeing a specific number may activate color-sensitive cortex regions and trigger a sensation of color (Brang et al., 2008; Hubbard et al., 2005). Seeing the number 3 may evoke a taste sensation (Ward, 2003). For many people, an odor, perhaps of mint or chocolate, can evoke a sensation of taste