sensation & perception

Important TermsImportant TermsSensation: Sensation: a sensory message; transmission a sensory message; transmission of information about the environment to the of information about the environment to the brain.brain.

Transduction: Transduction: converting physical energy converting physical energy into neural energy.into neural energy.

Perception: Perception: the interpretation of a sensory the interpretation of a sensory message by the brain.message by the brain.

The Direction of SensationThe Direction of SensationPhysical EnergyPhysical Energy

The ReceptorThe Receptor

The Receptor CellThe Receptor Cell

A Neural SignalA Neural Signal

The BrainThe Brain

Subliminal PerceptionSubliminal Perception

Stimulation Stimulation below the below the threshold of threshold of conscious conscious awareness.awareness.There is no evidence to support There is no evidence to support subliminal perception subliminal perception occurring.occurring.

Reverse MaskingReverse MaskingThere is no evidence to support There is no evidence to support reverse masking causes reverse masking causes subliminal or any other subliminal or any other stimulation.stimulation.

VViissiioonnThe Structure of The Structure of the Eyethe EyeThe CorneaThe Cornea

The IrisThe Iris

The PupilThe Pupil

The LensThe Lens

The RetinaThe Retina

The FoveaThe Fovea

The Optic NerveThe Optic Nerve

The Back of the EyeThe Back of the EyeAt the rear of the At the rear of the eye is the retina eye is the retina containing the containing the receptor cells.receptor cells.

Before light gets to Before light gets to the retina, it passes the retina, it passes through blood through blood vessels & vessels & connecting cells.connecting cells.

The RodsThe RodsRods are absent from Rods are absent from the foveathe foveaRods become more Rods become more common toward the common toward the periphery of the retinaperiphery of the retinaRods have low Rods have low sensitivity to detail sensitivity to detail because many of them because many of them funnel into a single funnel into a single postsynaptic neuronpostsynaptic neuron

TThhe e CCoonneessMore common toward the center of the retinaFewer in the periphery of the retinaMore of them because fewer cones funnel onto a single postsynaptic neuron

The RetinaThe RetinaThe RodsThe RodsSpecialized for low light

The ConesThe ConesColor vision and bright lightThe rods and cones The rods and cones connect to connect to BI-POLARBI-POLAR cells. cells. The bi-polar cells connect The bi-polar cells connect to to GANGLION CELLSGANGLION CELLS..The ganglion cells’ axon The ganglion cells’ axon becomes the becomes the OPTIC OPTIC NERVENERVE..

SSeeeeiinngg CCoolloorrTrichromatic Trichromatic TheoryTheoryThree types of Three types of cones: cones: RED, RED, GREEN, GREEN,

and and BLUEBLUE..

Opponent Process Opponent Process TheoryTheoryCones are in Cones are in opposing pairs. opposing pairs. When one is When one is activated, the other activated, the other is suppressed.is suppressed.

White/White/BlackBlack

Blue/Blue/OrangeOrange

Green/Green/RedRed

The Visible SpectrumThe Visible SpectrumWe see about 1/1 We see about 1/1 millionth of a meter of millionth of a meter of the whole the whole electromagnetic electromagnetic spectrum.spectrum.

The electro-magnetic The electro-magnetic spectrum includes both spectrum includes both invisible long and short invisible long and short waves.waves.

Perceiving Perceiving RealityReality

Apparent Apparent MotionMotion The Autokinetic EffectThe Autokinetic EffectApparent motion of a single light in Apparent motion of a single light in total darkness.total darkness.

The Phi PhenomenonThe Phi PhenomenonA series of blinking lights.A series of blinking lights.

The Stroboscopic The Stroboscopic EffectEffectThe “jerky” effect of a strobe light The “jerky” effect of a strobe light blinking in total darkness with blinking in total darkness with movement.movement.

Perceptual Organizational PrinciplesPerceptual Organizational Principles

Figure – GroundFigure – Ground The simplest type of The simplest type of

organizational principleorganizational principle

Reversible Figure-GroundReversible Figure-Ground

Unclear Figure-GroundUnclear Figure-Ground

Illusory Figure-GroundIllusory Figure-Ground

Filling in the GapsFilling in the Gaps

ClosureClosureThe tendency to perceive an object The tendency to perceive an object or shape even when the form isn’t or shape even when the form isn’t complete.complete.

Perceiving Depth & Perceiving Depth & DistanceDistance

SimilaritySimilaritySimilar objects are Similar objects are perceived as being perceived as being together.together.

ProximityProximityStimuli close together are Stimuli close together are perceived as being perceived as being together.together.

Perceiving Depth & Perceiving Depth & DistanceDistance

InterpositionInterpositionSomething is placed between Something is placed between the eye and the object.the eye and the object.

Texture GradientTexture GradientTextured objects further away Textured objects further away look smooth.look smooth.

Perceiving Depth & Perceiving Depth & DistanceDistance

Linear PerspectiveLinear PerspectiveConvergence of lines or the Convergence of lines or the vanishing point in art. vanishing point in art.

Aerial PerspectiveAerial Perspective Close objects appear clearer Close objects appear clearer than those farther away.than those farther away.

Perceiving Depth & Perceiving Depth & DistanceDistance

Motion ParalaxMotion ParalaxCloser objects seem to move Closer objects seem to move faster than those farther away faster than those farther away when in motion.when in motion.

Light and Light and ShadowShadowGives objects the appearance of Gives objects the appearance of three dimensions.three dimensions.

Perceiving Depth & Perceiving Depth & DistanceDistance

Relative SizeRelative SizeThe smaller the image of an object is on the retina, the farther away it seems.

Relative HeightRelative HeightObjects higher in the visual field are perceived as farther away.

The Optic ChiasmThe Optic ChiasmPoint in the temporal Point in the temporal area of the brain where area of the brain where the optic nerve crosses the optic nerve crosses over from left to right.over from left to right.This is where stereo vision is This is where stereo vision is created.created.

Stereoscopic VisionStereoscopic Vision

Seeing the world in Three-DimensionsSeeing the world in Three-Dimensions

Binocular cues:Binocular cues:Retinal DisparityRetinal Disparity

The difference between the two eyes

ConvergenceConvergence

The eyes focusing close up

Stereoscopic VisionStereoscopic Vision

Seeing depth naturally

Perceptual ConstanciesPerceptual Constancies

Size ConstancySize ConstancyObjects continue to remain the Objects continue to remain the same size no matter how same size no matter how distant.distant.

Shape ConstancyShape ConstancyObjects remain the same shape Objects remain the same shape even if the image on the retina even if the image on the retina shows a different shape.shows a different shape.

Color ConstancyColor ConstancyInfluenced by lighting (artificial, Influenced by lighting (artificial, colored, or natural).colored, or natural).

Visual IllusionsVisual Illusions

More IllusionsMore Illusions

More IllusionsMore Illusions

HearingHearingThe Construction The Construction of the Earof the EarThe Pinna

The External Auditory Canal

The Ear Drum

The Hammer, Anvil, & Stirrup

The Oval Window

The Cochlea

The Hair Cells

The Nerve Cells

The Auditory Nerve

Inside the EarInside the EarThe Middle & The Middle & Inner EarInner EarThe EardrumThe Eardrum

The Hammer, Anvil, The Hammer, Anvil, & Stirrup& Stirrup

The Oval WindowThe Oval Window

The CochleaThe Cochlea

The Semicircular The Semicircular CanalsCanals

The CochleaThe CochleaThe Cochlea is The Cochlea is the organ of the organ of hearinghearing

Contained within Contained within the Cochlea are the Cochlea are the hair cellsthe hair cellsThe hair cells are connected The hair cells are connected to neurons and the axons of to neurons and the axons of the neurons create the the neurons create the auditory nerve.auditory nerve.

Theories of HearingTheories of Hearing The Place Theory of The Place Theory of

HearingHearingDifferent areas of the basilar membrane Different areas of the basilar membrane respond to different frequencies. respond to different frequencies. High tones register most strongly at the base of the cochlea (near the oval window), lower tones mostly move the hair cells near the outer tip of the cochlea.

The Frequency Theory The Frequency Theory of Hearingof HearingThe entire basilar membrane acts like a The entire basilar membrane acts like a microphone, vibrating as a whole in microphone, vibrating as a whole in response to sound. The nerve receptors response to sound. The nerve receptors send out impulses that are tied directly send out impulses that are tied directly to the frequency of the sounds: to the frequency of the sounds: Frequency = ImpulsesFrequency = Impulses

DeafnessDeafnessConduction Conduction DeafnessDeafnessWhen the eardrums or ossicles are When the eardrums or ossicles are damaged or immobilized by disease or damaged or immobilized by disease or injury reducing the transfer of sound to injury reducing the transfer of sound to the inner ear.the inner ear.

Nerve DeafnessNerve DeafnessWhen there is damage to the hair cells When there is damage to the hair cells or auditory nerve.or auditory nerve.

Stimulation Stimulation DeafnessDeafnessCaused by a noisy environment Caused by a noisy environment damaging the hair cells in the cochlea.damaging the hair cells in the cochlea.

The Sense of SmellThe Sense of SmellOlfactionOlfactionA chemical senseA chemical sense

The RouteThe RouteNerve EndingsNerve Endings to to The NeuronsThe Neurons to to The Olfactory BulbThe Olfactory Bulb to to The Limbic The Limbic SystemSystem

The Lock & Key The Lock & Key TheoryTheory

5 Odors Identified5 Odors IdentifiedFloral, Camphoric, Musky, Minty, & Floral, Camphoric, Musky, Minty, & EtherishEtherish

TasteTasteGustationGustationA Chemical SenseA Chemical Sense

The RouteThe RouteThe Tongue The Tongue toto The The Papillae Papillae toto The Taste Buds The Taste Buds toto The Brain The Brain

5 Tastes 5 Tastes IdentifiedIdentifiedSweet, Sour, Salty, Bitter, Sweet, Sour, Salty, Bitter, & Umami& Umami

Grace and BalanceGrace and Balance

The Kinesthetic The Kinesthetic SenseSenseKeeps us informed about Keeps us informed about movement of body parts & movement of body parts & their position in relation to their position in relation to each other.each other.Muscle Movement, Posture, Muscle Movement, Posture, & Joints& JointsInformation comes from Information comes from stretch receptors, the stretch receptors, the tendons, & the internal tendons, & the internal organs.organs.

Balance & EquilibriumBalance & Equilibrium

Vestibular Vestibular SenseSenseThe Vestibular Sense keeps us informed about balance & the position of our body in space.Hair cells in the inner ear bend in Hair cells in the inner ear bend in relation to the position & relation to the position & movement of the head giving movement of the head giving information that the brain uses to information that the brain uses to help us maintain our balance and help us maintain our balance and to sense changes in our movement to sense changes in our movement through space.through space.

The Tactile SensesThe Tactile Senses

TouchTouchSkin receptors that make us aware of how & where we’re being touched.

PressurePressureReceptors beneath the skin that make us aware of deeper touch.

TemperatureTemperatureReceptors are found just beneath the skin to give the sensation of hot, cold, and warm.

The Tactile SensesThe Tactile Senses

PPaaiinnPain is adaptive & lets us know there’s something wrong.Pain receptors are located not just in the skin, but also in other parts of the body: muscles, joints, ligaments, teeth, & the internal organs.

2 Kinds of Pain2 Kinds of PainDull (slow) painLong axonsSharp (fast) painShort axons

The Gate The Gate Control Theory Control Theory of Painof PainThere is a “neurological gate” There is a “neurological gate” in the spinal cord controlling in the spinal cord controlling the transmission of pain the transmission of pain messages to the brain.messages to the brain.Dull, throbbing pain is conducted through the gate by thinner & slower nerve fibers that carry signals for touch & temperature.Faster, thicker nerve fibers cause a bottleneck at the gate, blocking the passage of other messages.

What Influences Pain?What Influences Pain?

The Biosocial TheoryThe Biosocial TheoryThe interaction of biological, psychological, and cultural The interaction of biological, psychological, and cultural factors influence the intensity & duration of painfactors influence the intensity & duration of pain..

The Placebo EffectThe Placebo EffectAny direct or indirect procedure or object that can cause Any direct or indirect procedure or object that can cause relief from pain or illness.relief from pain or illness.

With pain, it appears to come from the release of endorphins.With pain, it appears to come from the release of endorphins.

What Influences Our Perceptions?What Influences Our Perceptions?

We respond selectivelyWe respond selectivelyGenetics & genetic predispositionsGenetics & genetic predispositionsIndividual characteristicsIndividual characteristics

MotivationMotivation

ValuesValues

ExpectationsExpectations

Cognitive StyleCognitive Style

PersonalityPersonality

Experience & CultureExperience & Culture