Sensation and Perception

Flashcards related to sensation and perception.

Sensation

Sensory receptors and nervous system receive and represent stimulus energies from our environment

Transduction

Transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret

Absolute Threshold

Minimum stimulus energy needed to detect a particular stimulus 50% of the time

Subliminal

Input below the absolute threshold for conscious awareness

Priming

Activating, often unconsciously, associations in our mind, setting us up to perceive, remember, or respond to objects or events in certain ways

Difference Threshold

The minimum difference that a person can detect between any two stimuli half the time

Weber’s Law

For an average person to perceive a difference, two stimuli must differ by a constant minimum percentage (not a constant amount)

Subliminal Stimuli

Too weak to detect 50 percent of the time; below the absolute threshold

Sensory Adaptation

Diminished sensitivity because of constant stimulation

Perception

Brain organizes and interprets sensory information, enabling us to recognize objects and events as meaningful

Bottom-Up Processing

Begins with the sensory receptors and works up to the brain’s integration of sensory information

Top-Down Processing

Guided by higher-level mental processes; we construct perceptions drawing on our experience and expectations

Perceptual Set

Mental predisposition to perceive one thing and not another

Wavelength

Distance from one wave peak to the next

Hue

Color experienced

Amplitude

Height of a wave

Intensity

Amount of energy contained in a wave; influences brightness

Cones

Sensitive to detail and color

Rods

Sensitive to faint light

Optic Nerve

Carries neural impulses from the eye to the brain; highway from eye to brain

Blind Spot

The point at which the optic nerve leaves the eye, where no receptor cells are located

Fovea

The central focal point in the retina, around which the eye’s cones cluster

Young-Helmholtz Trichromatic (Three-Color) Theory

Eye must have three corresponding color receptor types, each sensitive to red, green, and blue wavelengths

Hering’s Hypothesis (Opponent-Process Theory)

Opposing retinal processes (red-green, blue-yellow, white-black) enable color vision

Parallel Processing

Brain’s ability to do many things simultaneously (visual scene is first divided into subdimensions)

Grouping

The perceptual tendency to organize stimuli into coherent groups

Proximity

Grouping nearby figures together

Continuity

Perceiving smooth, continuous patterns, rather than discontinuous ones

Closure

Filling in gaps to create a complete, whole object

Depth Perception

The ability to see objects in three dimensions, although the images that strike the retina are two-dimensional

Perceptual Constancy

Objects are perceived as unchanging (having consistent color, brightness, shape, and size), even as illumination and retinal images change

Sound Waves

Amplitude determines intensity/loudness, length/frequency determines pitch

Pitch

Tone’s experienced highness or lowness (depends on frequency)

Sound Waves

Bands of compressed and expanded air that human ears detect and transform into neural impulses

The Ear

Vibrating air (sound waves) enters the outer ear and passes through the auditory canal to the eardrum…

Place Theory

Links the pitch heard with the place where the cochlea’s membrane is stimulated; best explains high pitches

Frequency Theory

The rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling its pitch to be sensed; explains low pitches

Five Senses

Touch, Taste, Smell, Sight, Sound

Touch

Mix of four distinct skin senses: Pressure, Warmth, Cold, Pain

Gate-Control Theory

Spinal cord contains a neurological “gate” that either blocks pain signals or allows them to pass on to the brain

Taste

Indicates sweet (energy source), salty (sodium essential), sour (potentially toxic acid), bitter (potential poisons), umami (proteins to grow and repair tissue)

Smell

Chemical sense of smell via olfactory receptor cells located in the olfactory bulb in the nose