AP Psychology Unit 3: Sensation and Perception

Sensory Psychology

The study of senses and their effect on our behavior

Psycho Physics

The Study of the relationship between physical stimuli and mental phenomenon

Sensation

The process by which a stimulated receptor (eyes, ears, nose, skin) creates a pattern of neural messages that represent the stimulus in the brain

Perception

A mental process that assigns meaning and interpretation to the incoming neural sensory messages and patterns.
An individual's interpretation of sensation.

Bottom Up Processing

Perception that involves starting with an incoming stimulus and WORKING UPWARDS until a representation of the object is formed in our minds
example: having bits and pieces help you perceive something

Top Down Processing

Perception that EMPHASIZES A PERSONS EXPECTATIONS, concept memories, and other cognitive factors, rather than individual characteristics of the stimuli to make meaning.
driven by CONTEXT

Context effects

Experiences and environmental factors shape our perception

perceptual set

Perceptual set is a readiness to detect a particular stimulus in a given situation
Expectation, emotion, culture, and motivation all weigh in and prepare the mind to deliver the best perception

Schemata

Mental representations of how we expect the world to be.
Beginning in birth, people begin to organize new perceptions into this. We form this based on our experiences in life.

Depth Perception

the visual ability to perceive the world in three dimensions (3D) and the distance of an object.

Visual Cliff Experiment

created by E.J. Gibson, used to determine when infants can perceive depth

Gestalt Perception

Gestalt psychologists emphasize that organisms perceive entire patterns or configurations and not merely individual components.

Figure

The part of a pattern that commands attention

Ground

The part of a pattern that does not command attention aka background

Illusions

When your mind interprets an image that is demonstrably incorrect
Top down processing can make you vulnerable to this.

Sensory Adaptation

Reduction in sensitivity to a stimulus after constant exposure to it.
example: not feeling your watch after wearing it on your left arm every day.

absolute threshold

It is the minimum stimulation needed for a person to detect any stimuli 50% of the time and the lowest level of stimulus needed to detect a smell, a sound, or a ray of light.
example: not feeling hair that falls on you, but feeling hair that is closely touching you

Just Noticeable Difference (JND)

The smallest amount by which a stimulus can be changed and the difference be detected, 50% of the time through a great change.
example: when the TV is turned down drastically where you can sense the difference

Signal Detection Theory

States that sensation detection depends on the characteristics of the stimulus, the background stimulation and the condition of a person detecting.
Example: professionals who are aware of airplanes that control air trafficking

Transduction

The sensory process that converts energy such as light or sound waves, into the form of electrochemical neural messages.

Cornea

The clear tissue that covers the front of the eye

Pupil

The pupil is the black circle in the center of the iris, which is really an opening in the iris, as it lets light enter deeper portions of the eye

Iris

Colored part of the eye that has muscles attached to help the pupil control how much light comes through

Lens

It focuses and bends light directly on the back of the eyeball, a part called the retina

Accomodation

Bending of light by the lens

Nearsightedness

Myopia (light that cannot reach retina)

Farsigtedness

Hyperopia (light that is past the retina)

Retina

Neural tissue lining on the back of the surface of the eye. It connects to the optic nerve

Fovea

Spot on the center of retina
Has the sharpest vision and the most rods and cones

Photoreceptors

Light sensitive neuros (rods and cones)

Rods

Sensitive to dim color: help us see shades of white, blacks, and grays

Cones

Sensitive to colors but not dim light, responsible to help us see colors

Optic Nerve

The bundle of neurons that carries the visual information from the retina to the brain

Blind Spot

The point where the optic nerve exits the eye and where there are no photoreceptors. Any stimulus that falls on this area cannot be seen.

David Hubel

First to analyze the flow of nerve impulses from the retina to the sensory and motor centers of the brain

Bipolar Cells

Gather info from rods and cones and pass it to ganglion cells

Ganglion cells

Bundles of axons that form the optic nerve which is connected to the visual cortex

Parallel Processing

The ability of the brain to simultaneously process several aspects of visual data such as color, motion, shape, and depth.

Visual Cortex

part of the brain that works to transform neural impulses into visual sensations for our brain to perceive and interpret

Synesthesia

When neural connections are crossed in which the stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory pathway
example: tasting colors or sounds

Color Blindness

A color deficiency usually inherited and most of the time prone to having difficulty with greens and reds

Trichromatic (Three Color) Theory

we see color through three types of cones in our retina. We have cones that detect red, blue, and green and from a combination of those three colors we can see almost every other color

Opponent Process Theory

The theory states that we have three types of receptor cones and they handle a pair of colors. If one sensor/color is firing, it slows or prevents the other from firing.

Hearing

The ability to perceive sounds by detecting vibrations through an organ such as the ear

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

Cochlea

snail-shaped structure of the inner ear that is filled with fluid and hair cells

Oval Window

Incoming vibrations cause this (cochlea membrane) to shake, moving the fluid and making ripples onto the basilar membrane

Basilar Membrane

Hair cells in the cochlea

Auditory nerve

the nerve that carries impulses from the inner ear to the thalamus, to the temporal lobe of brain, resulting in the perception of sound

Conduction Deafness

an inability to hear, resulting from DAMAGE to the structures of the middle or inner ear.

Nerve Deafness (Sensorineural Deafness)

is an inability to hear, linked to a deficit in the body's ability to transmit IMPULSES from the cochlea to the brain.

Selective Attention

the process of directing our awareness to relevant stimuli in the environment.

Vestibular Sense

the sense of body movement and position, including the sense of balance
Example: when you tilt, fluid tilts in the cochlea , sending messages to your brain making you aware you are tilted

Kinesthetic Sense

Keeps track of your posture and body parts, relative to each other.
Provides constant sensory feedback about what the muscles in your body are doing
Example: closing your eyes with your hand up and being aware that your hand is up

Olfaction

sense of smell and has a close connection to memory

Smell

Odor molecules in the air interact with sensory receptor proteins associated with hairs in the nose
The hairs convey information to the brain's olfactory bulb which communicate neural messages to the brain

Gustation

sense of taste

Human Taste

Sweet, Sour, Bitter, Salty, Umami (savory)

Papilae

covers our tongues and has taste buds which are receptor cells that transmit neural messages to the paretial lobe

Skin Senses

touch, pressure, temperature, pain

Touch receptors

stimulated by mechanical, chemical, and thermal energy in the somatosensory cortex of the brain.
Most common in face and hands

Gate Control Theory

An explanation for pain control that proposes we have a neural gate that can, under some circumstances, block incoming pain signals to the brain