Unit 1 : Vocab 3

Sensation vs. Perception

Sensation vs. Perception

Detecting stimuli vs. interpreting and organizing those stimuli.

Absolute Threshold

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

JND (Just Noticeable Difference)

How much stimulus must change before it becomes noticeably different.

Sensory adaptation

Reduced sensitivity to stimulation that results from repeated or prolonged exposure to that stimulation.

Weber’s Law

To be perceived as different, two stimuli must differ by a constant percentage rather than a constant amount.

Synesthesia

A condition where one sense is simultaneously perceived as if by one or more additional senses.

Lens

Focuses images on the retina and accommodates to focus on specific objects by changing shape.

Retina

Neural tissue lining the back of the eyeball’s interior, containing receptors for vision that transduce light energy into electrochemical energy.

Iris

The colored part of the eye that controls the amount of light entering the eye.

Pupil

The opening in the iris through which light enters the eye.

Cornea

The transparent front part of the eye that protects it and bends light toward the lens.

Optic Nerve

The nerve that transmits visual information from the retina to the brain.

Ganglion Cells

The last layer of photoreceptors within the retina that sends visual signals to the brain.

Transduction

The process of converting one form of energy into another (e.g., physical energy to electrical signals).

Blind Spot

The area of the retina where no rods or cones exist.

Photoreceptors

Cells in the retina that respond to light and convert it into electrical signals.

Rods vs Cones

Rods are not involved in color vision and work in low light, whereas cones are involved in color vision and work in bright light.

Accommodation

The adjustment in the lens of the eye to focus on near or far objects.

Nearsighted vs Farsighted

Nearsightedness occurs with too much curvature in the cornea (sees near), while farsightedness occurs with too little curvature in the cornea (sees far).

Trichromatic Theory vs Opponent-Process Theory

Trichromatic theory states that all colors come from three colors, while opponent-process theory states there are two opponent systems (blue-yellow & red-green).

Afterimages

Visual sensations that remain after a stimulus is removed.

Dichromatism

A type of color blindness where one of the three primary colors is not perceived.

Monochromatism

A condition in which only one color is perceived.

Prosopagnosia

A condition characterized by the inability to recognize faces.

Blindsight

The ability to respond to visual stimuli without consciously seeing them.

Wavelength vs Amplitude

Wavelength refers to the distance between peaks in a wave; amplitude refers to the height of the wave.

Place Theory

A theory of pitch perception that states different parts of the cochlea are activated by different frequencies.

Volley Theory

A theory that explains how sounds above 1000 Hz are perceived, focusing on groups of neurons firing in a volley.

Frequency Theory

A theory that suggests the frequency of the auditory nerve impulses corresponds to the frequency of the sound.

Sound Localization

The ability to identify the origin of a sound in the environment.

Conduction Deafness

Hearing loss caused by problems in the outer or middle ear obstructing sound.

Sensorineural Deafness

Hearing loss caused by damage to the inner ear or auditory nerve.

Inner, Outer, Middle Ear

The three parts of the ear involved in hearing: the inner ear contains the cochlea, the outer ear collects sound, and the middle ear contains the ossicles.

Tympanic Membrane

Also known as the eardrum, it vibrates in response to sound waves.

Cochlea

A spiral-shaped organ in the inner ear that transduces sound through hair cells.

Hair Cells

Sensory cells in the cochlea that convert sound vibrations into electrical signals.

Olfactory Bulb

A neural structure involved in the sense of smell.

Transduction of nose

The process by which odor molecules are converted into neural signals.

Gustation

The sense of taste, which involves taste receptors on the tongue.

Structures of the Tongue

Includes taste buds which contain receptors for taste.

Taste receptors

Cells on the tongue that detect taste substances.

Chemical Senses

Senses that rely on chemicals to produce sensations (e.g., taste and smell).

Transduction of touch

The process of converting physical pressure on the skin into neural signals.

Warm vs Cold receptors

Skin receptors that respond differently to temperature variations.

Gate Control Theory

A theory that explains pain perception and how certain nerve impulses can be blocked.

Phantom Limb

The sensation that an amputated or missing limb is still attached and functioning.

Vestibular vs Kinesthetic

Vestibular sense relates to balance and spatial orientation, while kinesthetic sense relates to the position and movement of body parts.

Semi-circular canals

Fluid-filled structures in the inner ear that help maintain balance.

Proprioception

The sense of the relative position of one's own body parts and strength of effort used in movement.