How can we help?

You can also find more resources in our Help Center.

61 terms

Chapter 6: Sensation and Perception

STUDY
PLAY
Sensation
The detection of physical energy emitted or reflected by physical objects; it occurs when energy in the external environment or the body stimulates receptors in the sense organs.
Perception
The process by which the brain organizes and interprets sensory information.
Sense receptors
Specialized cells that convert physical energy in the environment or the body to electrical energy that can be transmitted as nerve impulses to the brain.
Doctrine of specific nerve energies
The doctrine that different sensory modalities, such as vision and hearing, exist because signals recieved by the sense organs stimulate different nerve pathways leading to different areas of the brain.
Absolute threshold
The smallest quantity of physical energy that can be reliable detected by an observer.
Difference threshold
The smallest difference in stimulation that can be reliably detected by an observer when two stimuli are compared; also calles the just noticible difference.
Signal-detection theory
A psychophysical theory that divides the detection of a sensory signal into a sensory process and a decision process.
Sensory adaptation
The reduction or disapperance of sensory responsiveness that occurs when stimulation is unchanging or repetitious.
Selective attention
The focusing of attention on selected aspects of the environment and the blocking out of others.
Sensory deprivation
The absence of normal sevels of sensory stimulation.
Retina
Neural tissue that lines the back of the eyeball's interior and contains the receotirs for vision.
Rods
Visual receotirs that resoind to dim light but that are not involved in color vision.
Cones
Visual receptors involved in color vision.
Dark adaptation
A processs by which visual receptors become maximally sensitive to dim light.
Ganglion cells
Neurons in the retina of the eye that gather information from receptor cells (by the way of intermediate bipolar cells); their axons make up the optic nerve.
Feature detectors
Cells in the visual cortex that are sensitive to specific features of the environment.
Trichromatic theory
A theory of color perception that proposes three mechanisms in the visual system, each sensitive to a certian range of wavelengths; their interaction is assumes to produce all the different experiences of hue.
Opponent-process theory
A theory of color perception, which assumes that the visual system treats pairs of colors as opposing or antagonistic.
Gestalt principles
Principles that describe the brain's organization of sensory building blocks into meaningful units and patterns.
Binocular cues
Visual cues to depth or distance requiring two eyes.
Convergence
The turning of the eyes inward, which occurswhen they focus on a nearby objects.
Retinal disparity
The slight difference in lateral seperation between two objects, as seen by the left eye and the right eye.
Monocular cues
Visual cues to depth or distance, which can be used by one eye alone.
Perceptual constancy
The accurate perception of objects as stable or unchanged despite changes in the sensory patterns they produce.
Perceptual illusion
A erroneous or misleading perception on reality.
Loudness
The dimension of auditory experience related to the intensity of a pressure wave.
Pitch
The dimension of auditory experience related to the frequency of a pressure wave; height or depth of a tone.
Timbre
The distinguishing quality of a sound; the demension of auditory experience related to the complexity of the pressure wave.
Cochlea
A snail-shaped, fluid-filled organ in the inner ear, containing receptors for hearing.
Papillae
Knoblike elevations on the tongue, containing the tastebuds.
Taste buds
Nests of taste-receptor cells.
Gate-control theory
The theory that the experience of pain depends in part on whether pain impulses get past a neurological "gate" in the spinal cord and thus reach the brain.
Neuromatrix theory
The theory that a matrix of neurons in the brain is capable of generating pain (and other sensations) in the absence of signals from sensory nerves.
Kinesthesis
The sense of body position and movement of body parts.
Equilibrium
The sense of balance.
Semicircular canals
Sense organs in the inner ear, which contribute to equilibrium by responding to rotation of the head.
Perceptual test
A habitual way of perceiving, based on expectations.
Hue
The deminsion of visual experience specified by color names and related to the wavelength of light.
Brightness
Lightness of luminance; the dimension of visual experience related to the amount of light emitted from or relected by an object.
Saturation
Vividness or purity of color; the dimension of visual experience related to the complexity of light waves.
Cornea
Transparent part that covers the eye.
Iris
Part of eye that gives it color.
Pupil
Round opening, surrounded by the iris.
Fovea
Center of retina where vision is sharpest.
Proximity
Things that are near each other tend to be grouped together.
Closure
When the brain completes uncompleted shapes.
Similarity
Things that are alike in some way tend to be percieved as belonging together.
Continuity
Lines and patterns tend to be percieved as continuing in time or space.
Interposition
When an object is interposed between the viewer and a sencond object, partially blocking the view of the second object, the first object is percieved as being closer.
Linear perspective
When two lines known to be parallel to appear to be coming together or converging, they imply the existance of depth.
cilia
Important receptor cells that look like bristles and are called hair cells.
Basilar membrane
What the hair cells of the cochlea are embeded in
Needs
When we need smething, have an interest in it, or want it, we are especially likely to percieve it.
Beliefs
What we hold to be true about the world can affect the interpretation of ambiguous sensory signals.
Emotions
Influence our interpretation of sensory information.
Expectaitions
Previous experiences often affect how we percieve the world.
ESP
People who claim they can sens and recieve mesages about the world without relying on usual sensory channels.
Telepathy
Direct communication from one mind to another without the usual visual, auditory, and other sensory signals.
Clairvoyance
The perception of an event or fact without normal sensory input.
Precognition
Perception of an event that has not yet happened.
Out-of-body experiences
Involve perception of one's own body from "outside," as an observer might see it.