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Chapter 4
Sensation and Perception
Term | Definition |
---|---|
sensation | simple stimulation of a sense organ |
perception | the organization, identification, and interpretation of a sensation in order to for a mental representation |
transduction | what takes place when many sensors in the body convert physical signals from the environment into encoded neural signals sent to the central nervous system |
psychophysics | methods that measure the strength of a stimulus and the observer's sensitivity to that stimulus |
absolute threshold | the minimal intensity needed to just barely detect a stimulus |
just noticeable difference (JND) | the minimal change in a stimulus that can jut barely be detected |
weber's law | the just noticeable difference of a stimulus is a constant proportion despite variations in intensity |
signal detection theory | an observation that the response to a stimulus depends other on a person's sensitivity to the stimulus in the presence of noise and on a person's response criterion |
sensory adaptation | sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions |
retina | light-sensitive tissue lining the back of the eyeball |
accommodation | the process by which the eye maintains a clear image on the retina |
cones | photoreceptors that detect color, operate under normal daylight conditions, and allow us to focus on fine detail |
rods | photoreceptors that become active under low-light conditions for night vision |
fovea | an area of the retina where vision is the clearest and these are no rods at all |
blind spot | a location in the visual field that produces no sensation on the retina because the corresponding area of the retina contains neither rods nor cones and therefore has no mechanism to sense light |
receptive field | the region of the sensory surface that, when stimulated, cause a change in the firing rate of that neuron |
area V1 | the part of the occipital lobe that contains the primary visual cortex |
visual-form agnosia | the inability to recognize objects by sight |
binding problem | a phenomenon that concerns how features are linked together so that we see unified objects in our visual world rather than free-floating or miscombined features |
illusory conjunction | a perceptual mistake where features from multiple objects are incorrectly combined |
feature integration theory | the idea that focused attention is not required to detect the individual features that comprise a stimulus but is required to bind those individual fetures together |
perceptual constancy | a perceptual principle stating that even as aspects of sensory signals change, perception remains consistent |
monocular depth cues | aspects of a science that yield information about depth when viewed with only one eye |
binocular disparity | the difference in the retinal images of the two eyes that provides information about depth |
apparent motion | the perception of movement as a result of alternating signals appearing in rapid succession in different locations |
change blindness | a phenomenon that occurs when people fail to detect change to the visual details of a scene |
inattention blinds | a failure to perceive objects that are not the focus of attention |
pitch | how high or low a sound is |
loudness | a sound's intensity |
timbre | a listener's experience of sound quality or resonance |
cochlea | a fluid-filled tube that is the organ of auditory transduction |
basilar membrane | a structure in the inner ear that undulates when vibrations from the ossicles reach the cochlear fluid |
hair cells | specialized auditory receptor neurons embedded in the basilar membrane |
area A1 | a portion of the temporal lobe that contains the primary auditory cortex |
place code | the mechanism by which the cochlea encodes different frequencies at different locations along the basilar membrane |
temporal code | the mechanism by which the cochlea registers low frequencies via the firing rate of action potentials entering the auditory nerve |
haptic perception | the active exploration of the environment by touching and grasping objects with our hands |
referred pain | feeling of pain when sensory information from internal and external areas converges on the sam nerve cells in the spinal cord |
gate-control theory | a theory of pain perception based on the idea that signals arriving from pain receptors in the body can be stopped, or gated, by interneurons in the spinal cord via feedback from two directions |
vestibular system | three fluid-filled semicircular canals and adjacent organs located next to the cochlea in each inner ear |
olfactory receptor neurons (ORNs) | receptors cells that initiate the sense of smell |
olfactory bulb | a brain structure located above the nasal cavity beneath the frontal lobes |
pheromones | biochemical odorants emitted by other members of its species that can affect an animals behavior or physiology |
taste buds | the organ of taste transduction |