Chapter 4 Flashcards
Sensation
The process of receiving stimulus energies from the environment
Perception
The process of organizing and interpreting sensory information to give it meaning
Sensory receptors
Specialized cells that detect and transmit information about a sensory stimulus to sensory neurons and the brain
They are selective and have different pathways
Absolute threshold
The minimum amount of energy that people can detect
Difference threshold
Smallest difference in a stimulation required to discriminate one stimulus from the other
Signal detection theory
Focuses on decision making about stimuli in the presence of uncertainty
Perception is influenced by
Attention, beliefs, and expectations
Sensory adaptation
A change in responsiveness of the sensory system (our senses will begin to ignore a specific stimulus due to how long it has been around because we have gotten used to it)
Light can be described in terms of?
Wavelengths
The three characteristics of light waves
- Wavelength (hue)
- Amplitude (brightness)
- Purity (saturation)
Light passes through?
The cornea, then to the lens, and then to the retina
Retina
The light sensitive surface in the back of the eye that houses light receptors called rods
Rods function in low illumination
Cones react to?
Color
The fovea of the retina contains?
Cones and sharpens detail in image
The optic nerve
Transmits neural impulses to the brain. There it diverges into the optic chiasm
Optic chiasm
What we see in the left visual field is registered in the right side if the brain and vise versa
Information of the eye is integrated in the?
Occipital lobes of the cerebral cortex
The trichromatic theory
Three type of color receptors in the retina allow us to perceive three colors (green, red, and blue)
The opponent process theory
Cells in the visual system respond to red-green and blue-yellow colors
The eye and brain use what two methods to code colors?
The trichromatic theory and the opponent process theory
Shape perception
The ability to distinguish shapes from their background
Depth perception
The ability to perceive objects three dimensionaly and also depends on binocular (two) and monocular (one) cues.
Motion perception depends on
Specialized neurons, feedback from the body, and environmental cues
Perceptual constancy
The recognition that objects are stable despite changes that we see in them
Sound waves
Vibrations in the air that are processed by the auditory system
The variation of these waves influence what we hear
Perceptual interpretation of wavelength is?
Pitch (how high or low in tone a sound is)
Amplitude of wavelengths
Measured in decibels
The height of a wave
Is perceived as loudness
Complex sounds involve?
A blending of frequencies
Timbre
Tone saturation or perceptual quality of a sound
The outer ear consists of ?
The pinna and external auditory canal
The outer ear acts to?
Funnel sound to the middle ear
Middle ear
Hammer, anvil, and stirrup. They vibrate in in response to sound and transfer vibrations to the inner ear
The inner ear is
Fluid filled
Important parts of the inner ear
Oval window, cochlea, and basilar membrane
What generates nerve impulses (auditory)?
The movement of hair cells between the basilar membrane and the tectoral membrane
Place theory
Each frequency produces vibrations at a particular spot on the basilar membrane
The theory explains high frequency sounds but not low frequency
Frequency theory
Sounds frequency depends on how often auditory nerves fire
Volley principle
A cluster of neurons can fire impulses in rapid succession, producing a volley of impulses
Information regarding sound moves from?
The hair cells, to the auditory nerve, which carries information to the brain’s auditory areas
Cortical destination of most fibers is the?
Temporal lobes of the cerebral cortex
Localizing sound involves?
Both the timing and intensity of the sound
The skin senses include?
Touch, temperature, and pain
Touch is the detection of?
Mechanical energy, or pressure against the skin
Touch information travels through?
The spinal cord, brain stem, and thalamus, and on to the somatosensory areas of the parietal lobes
What responds to the increase and decrease in temperature?
Thermoreceptors under the skin
What sensation warns us about damage to the body?
Pain
The chemical sense of taste AND smell enable us to?
Detect and process chemicals in the environment
What is papillae?
Bumps on the tongue that contain taste buds. These are the receptors for tatse
The olfactory epithelium contains?
A sheet of receptor cells for smell in the roof of the nose
The kinesthetic senses provide information about?
Movement, posture, and orientation
What gives us information about balance and movement?
The vestibular sense
Receptors for the kinesthetic sense are embedded in?
Muscle fibers and joints
The semicircular canals in the inner ear contain?
The sensory receptors that detect head motion
How can we protect our sense organs?
Eating a low fat diet rich in vitamins and beta carotene
Wearing protective lenses for the eyes when we are out in the sun
Avoiding loud sounds
Experiences in nature can reduce stress and enhance well being
Sound at how many decibles is damaging to hearing if heard for a prolonged period?
80
Bottom-Up Processing
First time information and is sent to the brain. Is initiated by sensory input
Top-Down Processing
Initiated by cognitive process (higher level). Starts in the brain and occurs with information a person is already familiar with
Sensory receptors are also called
Afferent
Photoreception
Vision. Detection of light
Mechanoreception
Touch. Detection of pressure, vibrations, and movement
Chemoreception
Detection of chemical stimuli (smell and taste)
Synesthesia
Senses can become confused. One sense induces a sense into another
Weber’s law
To be perceived different two stimulus must differ by a constant minimum percentage
Subliminal perception
Influence of information below the level of consciousness
Rods
Sensitive to even dim light but not color
Trichomatic theory can not explain?
After images
Noise
Irrelevant and competing stimuli
Amplitude
Height of wave
Purity
Mixture of wavlengths
Wavlength
Distance between peaks
Blind spot
Where the optic nerve leaves the eye
Pathway of visual processing
- Retina
- Optic nerve
- Optic chiasm (divides)
- Thalamus
- Visual cortex
Color blindness
One or more cone type is inoperative
Pathway of auditory information
- Cochlea
- Auditory nerve
- Brain stem
- Temporal lobe
