Sensation and Perception- AP Psychology

Bottom-up processing

Using lines, angles, colors, and shapes to perceive an object. Only using the raw data. (Sensation)

Top-Down Processing

Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations. (Perception)

Transduction

Conversion of one form of energy into another. In sensation, the transforming of stimulus energies into neural impulses. Happens on the retina for vision.

Sensory Adaptation

Process by which we become more sensitive to weak stimuli and less sensitive to unchanging stimuli. Brain stops paying attention to the stimulus. Happens automatically.

Habituation

A gradual reduction in the strength of a response when a stimulus event is presented repeatedly. You could reacquire the sensation if focused on it. A choice to focus on it or not.

Absolute Threshold

The minimum stimulation needed to detect a particular stimulus 50 percent of the time

Difference Threshold

The minimum amount of difference that can be detected between two stimuli. Also known as the JND

Signal detection theory

How and when we detect stimuli based on motivation, experience, and expectation. Example - parents hearing baby cry but not a louder thunder storm.

Retina

Light sensitive layer of the eye; contains rods and cones. Transduction happens here for vision.

Accommodation

(physiology) the automatic adjustment in focal length of the lens of the eye

Rods

Dim-light and peripheral vision receptors. They do not provide either sharp images or color vision. Black and white only

Cones

Cone-shaped visual receptor cells; works best in bright light; responsible for viewing color; greatest density in the fovea

Fovea

A small area in the center of the retina, composed of cones, where visual information is most sharply focused. Clarity of vision

Optic Nerve

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

Blind Spot

The point at which the optic nerve leaves the eye where there are no photoreceptors. No vision here

Optic Chiasm

The crossing of the optic nerves from the two eyes at the base of the brain

Trichromatic Theory

three color receptors that produce the primary color senstions of red, green, and blue

Opponent-process theory

Your receptors can see one of two colors, red/green, yellow/blue, or black/white. explains the phenomenon of after images

Afterimages

Sensations that linger after the stimulus is removed. Most visual afterimages are negative afterimages, which appear in reversed colors. Explained by the Opponent-process theory

Frequency

In sound perception, it is the number of sound wave cycles per second. It determines pitch for sound

Amplitude

Height of a wave. It determines volume for sound

Tympanic membrane

Eardrum

Pitch

A tone's experienced highness or lowness; depends on frequency.

Timbre

Quality or pureness of sound

Place Theory

In hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated

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.

Basilar membrane

Where transduction takes place in the ear.
Within the cochlea of the ear that contains the hair cells

Conduction Deafness

An inability to hear resulting from damage to structures of the middle or inner ear.

Nerve Deafness

Inner-ear deafness resulting from damage to the cochlea, hair cells, or auditory nerve

Vestibular Sense

the sense of body movement and position, including the sense of balance

Kinesthetic Sense

Perception of the positions in space and movements of our bodies and our limbs

Olfaction

sense of smell

Pheromones

odorless chemicals that serve as social signals to members of one's species

Gustation

the sense of taste

Gate-Control Theory

The spinal cord contains a neurological, The spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain.

Placebo Effect

Experimental results caused by expectations alone

Feature Detectors

Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement

Perceptual Constancy

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

Ambiguous Figures

Images that are capable of more than one interpretation (Vase-Face, Old lady-Young lady, etc)

Gestalt psychology

A psychological approach that emphasizes that we perceive the whole rather than the sum of the parts.

Figure/Ground

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

Closure

The Gestalt principle that identifies the tendency to fill in gaps in figures and to see incomplete figures as complete

Binocular Cues

Depth cues, such as retinal disparity and convergence, that depend on the use of two eyes

Monocular Cues

Depth cues, such as interposition and linear perspective, available to either eye alone

Perceptual Set

A person's predisposition to perceive only what he or she wants or expects to perceive.

Change Blindness

A form of selective attention, where individuals failed to notice a change such as a person, color differences, or other obvious changes

Fechner and Weber

Difference threshold is not a set number but a proportion of stimulus change

Hubel and Wiesel

Nobel prize winning neurologists that discovered feature detectors

Cocktail Party effect

The ability to focus one's listening attention on a single talker among a mixture of conversations and background noises

parallel processing

the ability to attend to many sense modalities simultaneously such as shadow, movement, outline, etc.

Sensation:

The process of receiving information from the environment

Perception:

Assembling and making senses out of the information.

Schemas

Personal beliefs about things based on your life.

Subliminal Perception

There are all kinds of audiotapes that claim to reach your subconscious using subliminal and make you lose weight, quit smoking, not steal, etc.

telepathy

people to people

Clairvoyance

sensing danger

Precognition

knowing future events

Psychokineis

moving objects with mind

cornea

protective covering of the eye

pupil ( black circle in the center)

The opening through which light enters the eye

Iris

Colored part of the eye

Pupil size

size is sensitive to emotion. Evolutionary survival mechanism

Lens

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

Retina

Light sensitive layer of the eye; contains photoreceptors and neurons that process visual stimuli rods and cones

Photoreceptors:

2 types of neurons that respond to light (rods and cones)

Order of visual stimulus

photoreceptors, to bipolar cells, to ganglion cells, to the optic nerve

Blind Spot

Where the optic nerve connects to the retina. There are no photoreceptors and thus we have a
blind spot. This spot is small, and therefore our brain makes up for the missing data.

Nearsighted (myopia):

image crosses in front of the retina

Farsighted (hyperopia):

images crosses behind the retina

Visual Cortex

in the occipital lobe

Feature Detectors (Hubel and Wiesel)

cells in the visual cortex that respond to specific
features such as lines, and angles

Wavelength

distance of peaks – determines hue

Intensity

amplitude or height – brightness

Red

long wavelength

Blue

short wavelength

Yellow

High amplitude

Green

low amplitude

Purity

Saturation

Young –Helmholtz trichromatic (three-color) theory -3 color receptors

Red, Green, Blue – primary light

Opponent –process theory - can lead to an after image

Response in thalamus
o Red vs. green – Blue vs. yellow – Black vs. white
o If one is working the other cannot.
o If tire out one color of the pair when look away opposite happens

Color blindness

Defective cones in Retina ( 3 kinds)

pinna

external visual flap

Auditory canal:

part some people put a q-tip into to

Tympanic Membrane (Eardrum)

gateway to inner ear. Thin membranes that vibrates when sound strikes it.

Hammer, Anvil, Stirrup

also known as ossicles ( amplifies vibrations)

Oval window

(where the stirrup attaches to cochlea)

Cochlea:

bony tube in the inner ear that contains fluids as well as neurons that generate impulses.

Semicircular Canals

filled with fluid to help with balance. What gets messed up in a tilt-a-whirl.

Frequency

pitch (# of wavelengths in a given time)

Amplitude

volume (waves going up and down)

Purity

Timbre (richness in sound)

Hertz –

3 of waves per sec.

Conduction Hearing loss

Eardrum puncture or bones damaged, Can’t conduct vibrations, Hearing aids can help

Nerve hearing impairment (Sensorineural hearing loss)

Damage to hairs, due to heredity, age, and loud noises

Smell (Olfaction)

the area in the brain that controls scent is 7 times larger in dogs than in humans and 100 times
better. A large proportion of their brain is devoted to scent.

TASTE (Gustation)

Why would your dog eat a piece of candy, but a cat would turn its nose up at it? Dogs can taste sweetness
cats cannot Human taste qualities are sweetness, sourness, saltiness, bitterness and umami (savory).

Papillae

The little bumps that cover your tongue. The actual taste buds line the walls

Pressure

Your body is covered with hairs, many of them very tiny. When these hairs are touched, you sense it.
Certain areas of the body (like fingertips) are more sensitive to touch or pain

Temperature

98.6 = normal body temp. We respond to things hotter or colder than us (reference). This is why a
normal shower seems hot if you were out in the cold.

Pain

Pain originates at point of contact; message sent to spinal cord then to thalamus, to cerebral cortex
where the person registers the location and severity of the pain.