General Psychology- Chapter 3 (Sensation and Perception)
Eardrum
The thin membrane at the end of the ear canal that vibrates at a specific frequency when bombarded by sound waves.
Rods
A specific group of photoreceptors that are specialized to process dim light and are useful for night vision and peripheral vision.
Nociceptors
A type of receptor that responds to painful stimuli or stimuli that are capable of causing tissue damage.
Photoreceptor
A type of sensory receptor specifically for vision, which is located on the retina at the back of the eye.
Parvocellular pathway
A visual pathway for central vision and high spatial resolution images.
Magnocellular pathway
A visual pathway for peripheral vision and low spatial resolution images from the retina.
Attention
A concentrated mental effort that functions as a filter to ignore unimportant events and focus on important events.
Sensory adaption
A decline in a sensation's sensitivity resulting from the presence of a constant stimulus.
Blind spot
A gap in the retina due to the exit of the optic nerve where no photoreceptors are located; this causes a blind spot in the visual field during sensation.
Optic nerve
A large bundle of axons that leave the back of the eye and carries visual information to the visual cortex of the brain.
Absolute threshold
A method used to study the limits of sensation; the smallest amount of a physical stimulus that can be correctly detected 50% of the time.
Chemoreceptors
A class of receptors that detect water and lipid soluble chemicals.
Difference threshold
A method used to study the sensitivity of sensation; the smallest difference between two stimuli that can be correctly detected 50% of the time; this is also called the just-noticeable difference.
Occlusion
A phenomenon in which an object closer to a viewer appears to block another object that is farther away from the viewer.
Pixilation
A physical measure of resolution on a screen.
Weber's law
A principle in sensation that suggests that the size of the difference threshold is relative to the strength of the original stimulus.
Converge
The ability of the two eyes to move, rotate inward toward the nose; this is often referred to as being cross-eyed.
Amplitude
The amount of vibration or pressure in a sound wave often referred to as loudness.
Doppler shift
The change in pitch emitted by an object moving horizontally in space, in relation to a stationary observe.
Perception
The detailed process of interpreting and making sense of a combination of sensations.
Sensation
The detection of physical stimuli in the environment such as light waves, sound waves, pressure, or chemical molecules.
Sound shadow
The difference in sound intensity due to head blocking/deflecting some of the sound waves.
Dual or two-process theory
The idea that we localize low-frequency sounds by using time or phase differences, or both.
Acuity
The level of detail in a picture or the sharpness of an image.
Wavelength
The linear distance between two successive compressions or peaks in light waves.
Ciliary muscles
The muscles within the eye that stretch or compress the lens for the purpose of focusing the visual image.
Pinna
The outer funnel-shaped structure of the ear; normally, this is what people refer to as their ear.
Occipital lobe
The part of our brain responsible for processing the visual information.
Auditory cortex
The part of our brain that is primarily responsible for processing the auditory information.
Pupilloconstrictor zone
The part of the midbrain responsible for controlling the diameter of the pupil.
Optic chiasm
The point in the brain at which the optic nerves from each eye meet and partly cross over to the other side of the brain.
Transduction
The process of converting a physical stimulus into a meaningful and useful neural signal capable of being interpreted by the brain.
Retina
A light-sensitive membrane at the back of the eye that contains the sensory receptors for vision.
Inattentional blindness
Diverted attention resulting in failure of accurate scene detection as if we are blind to that event.
Lens
A biconvex crystalline structure that helps focus the visual image onto the retina in the back of the eye.
Stimulus
A quantifiable pattern of physical energy, which is able to interact with an organism and produce a change in the condition of the organism. That is, a stimulus is a type of environmental energy, like light, that we are capable of detecting and responding to.
Cones
A specific group of photoreceptors that are specialized to process color and are useful for daylight vision and high visual acuity.
"where" pathway
A visual pathway projected into the parietal lobe that integrates information about the location of an object.
"what" pathway
A visual pathway projected into the temporal lobe that responds to and integrates information about the size, color, and/ or the identity of an object.
Fovea
An area at the center of the retina that contains the highest density of cones; visual acuity is highest in this region.
Top-down processing
An information-gathering process starting from an individual's knowledge, expectations, and prior experiences.
Bottom-up processing
An information-gathering process starting from each individual stimulus.
Glare
An uncomfortable level of brightness.
Monaural cues
Auditory depth perception that occurs with just one ear.
Binaural cues
Auditory depth perception that occurs with the use of both ears.
Somesthesis
Bodily sensations.
Cutaneous sensitivity
Cutaneous senses (skin sense) refers touch, pressure, temperature, and pain (nociception).
Kinesthetic sensitivity
Kinesthetic sense refers to knowledge about spatial position and movement information occurring from mechanical stimulation of mobile joints, muscles, and tendons.
Equal loudness contours
Lines measuring the function of loudness and frequencies of sound waves.
Polymodal nociceptors
Nociceptors activated by a variety of high-intensity mechanical, chemical, and very hot or very cold stimuli.
Thermal or mechanical nociceptors
Nociceptors associated with sensations of sharp, stinging pain.
Ocular lubrication
Our visual system is able to make its own surface liquid which serves to keep the eye moist; natural tears are the mechanism for this process.
Hallucinations
Perceptions of experiences without corresponding external stimuli together with a compelling feeling that these are real.
Thermoreceptors
Receptors that are sensitive to changes in temperature.
Photoreceptors
Receptors that are sensitive to radiant electromagnetic energy (light).
Exteroceptors
Receptors that respond to environmental energy or stimuli that are occurring from the outside of one's body, such elements include light, sound, touch, and chemical agents.
Mechanoreceptors
Receptors that sense deformations and motion of solids, liquids, and gases. Mechanical forces are those that tend to deform or accelerate objects possessing mass.
Decibel
The scientific unit of measurement for loudness.
Taste buds
The sensory receptors for gustation that are located deep within porous structures on the tongue; there are five basic types of taste buds.
Pacinian corpuscles
The sensory receptors for touch located under the skin; these sensory receptors respond to pressure applied to the surface of the skin.
Interaural intensity difference
The slight difference in sound volume at it reaches one ear compared to the other.
Phase difference
The slight difference in the degree the sound wave is moving through its wave when it reaches one ear compared to the other.
Cochlea
The spiral structure in the inner ear that contains both fluid and the basilar membrane; the latter houses sensory receptors for audition.
Cornea
The surface of the eye.
Proprioceptors
These are sensory receptors that are activated by muscular movement or passive displacement of body parts.
Interoceptors
These receptors that are able to respond to materials inhaled, ingested, or passed, and to changes in chemical surroundings, mechanical pressure or shearing force.
Hair cells
Thin, hair-like structures that are the sensory receptors for audition; these are located on the basilar membrane inside the cochlea.
