Week 7 - Introduction to Sensation and Perception Flashcards
What is absolute threshold?
The smallest amount of stimulation needed for detection by a sense.
What is agnosia?
Loss of the ability to perceive stimuli.
What is anosmia?
Loss of the ability to smell.
What is audition?
Ability to process auditory stimuli. Also called hearing.
What is the auditory canal?
Tube running from the outer ear to the middle ear.
What are auditory hair cells?
Receptors in the cochlea that transduce sound into electrical potentials.
What is binocular disparity?
Difference is images processed by the left and right eyes.
What is bottom-up processing?
Building up to perceptual experience from individual
pieces.
What are chemical senses?
Our ability to process the environmental stimuli of smell
and taste.
What is binocular vision?
Our ability to perceive 3D and depth because of the difference between the images on each of our retinas.
What is the cochlea?
Spiral bone structure in the inner ear containing auditory
hair cells. Snail-shell-shaped organ that transduces mechanical vibrations into neural signals.
What are cones?
Photoreceptors of the retina sensitive to color. Located
primarily in the fovea
What is dark adaptation?
Adjustment of eye to low levels of light.
What is the dorsal pathway?
Pathway of visual processing. The “where” pathway
What is differential threshold?
The smallest difference needed in order to differentiate two stimuli.
What is the just noticeable difference?
The smallest difference needed in order to differentiate two stimuli
What is light adaptation?
Adjustment of eye to high levels of light.
What are mechanoreceptors?
Mechanical sensory receptors in the skin that response to
tactile stimulation.
What is multimodal perception?
The effects that concurrent stimulation in more than one
sensory modality has on the perception of events and
objects in the world.
What is nociception?
Our ability to sense pain.
What is olfaction?
Ability to process olfactory stimuli. Also called smell.
What is olfactory epithelium?
Organ containing olfactory receptors.
What is opponent-process theory?
Theory proposing color vision as influenced by cells
responsive to pairs of colors.
What are ossicles?
A collection of three small bones in the middle ear that
vibrate against the tympanic membrane.
What is perception?
The psychological process of interpreting sensory
information.
What is phantom limb/limb pain?
The perception that a missing limb still exists, or pain in limb that no longer exists.
What is the pinna?
Outermost portion of the ear.
What is the primary auditory cortex?
Area of the cortex involved in processing auditory stimuli.
What is the primary somatosensory cortex?
Area of the cortex involved in processing somatosensory
stimuli.
What is the primary visual cortex?
Area of the cortex involved in processing visual stimuli
What is the principle of inverse effectiveness?
The finding that, in general, for a multimodal stimulus, if
the response to each unimodal component (on its own) is
weak, then the opportunity for multisensory
enhancement is very large. However, if one
component—by itself—is sufficient to evoke a strong
response, then the effect on the response gained by
simultaneously processing the other components of the
stimulus will be relatively small.
What is the retina?
Cell layer in the back of the eye containing photoreceptors.
What are rods?
Photoreceptors of the retina sensitive to low levels of light.
Located around the fovea.
What is sensation?
The physical processing of environmental stimuli by the
sense organs.
What is sensory adaptation?
Decrease in sensitivity of a receptor to a stimulus after
constant stimulation.
What is the shape theory of olfaction?
Theory proposing that odorants of different size and shape
correspond to different smells.
What is signal detection?
Method for studying the ability to correctly identify
sensory stimuli.
What is the somatotopic map?
Organization of the primary somatosensory cortex
maintaining a representation of the arrangement of the
body.
What is somatosensation?
Ability to sense touch, pain and temperature.
What is superaddtive effect of multisensory integration?
The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own.
What are tastants?
Chemicals transduced by taste receptor cells.
What is top-down processing?
Experience influencing the perception of stimuli.
What is transduction?
The conversion of one form of energy into another.
What is trichromatic theory?
Theory proposing color vision as influenced by three
different cones responding preferentially to red, green and
blue.
What is the tympanic membrane?
Thin, stretched membrane in the middle ear that vibrates
in response to sound. Also called the eardrum. Ear drum, which separates the outer ear from the middle
ear
What is the ventral pathway?
Pathway of visual processing. The “what” pathway.
What is the vestibular system?
Parts of the inner ear involved in balance.
What is weber’s law?
States that just noticeable difference is proportional to the
magnitude of the initial stimulus.
What are a-fribers?
Fast-conducting sensory nerves with myelinated axons.
Larger diameter and thicker myelin sheaths increases
conduction speed
What are the three types of a-fibres and their properties?
- Aβ-fibers conduct touch signals from low-threshold mechanoreceptors with a velocity of 80 m/s and a diameter of 10 μm
- Aδ-fibers have a diameter of 2.5 μm and conduct cold, noxious, and thermal signals at 12 m/s.
- Aα fibres conducts proprioceptive information with a velocity of 120 m/s and a diameter of 20 μm.
What is allodynia?
Pain due to a stimulus that does not normally provoke
pain, e.g., when a light, stroking touch feels painful.
What are C-fibres?
C-fibers: Slow-conducting unmyelinated thin sensory
afferents with a diameter of 1 μm and a conduction
velocity of approximately 1 m/s. C-pain fibers convey
noxious, thermal, and heat signals; C-tactile fibers convey
gentle touch, light stroking.
What is chronic pain?
Persistent or recurrent pain, beyond usual course of acute
illness or injury; sometimes present without observable
tissue damage or clear cause.
What are C-pain or Aδ-fibers?
C-pain fibers convey noxious, thermal, and heat signals
What are C-tactile fibres?
C-tactile fibers convey gentle touch, light stroking
What are cutaneous senses?
The senses of the skin: tactile, thermal, pruritic (itchy),
painful, and pleasant.
What is decending pain modulatory system?
A top-down pain-modulating system able to inhibit or
facilitate pain. The pathway produces analgesia by the
release of endogenous opioids
What is endorphin?
An endogenous morphine-like peptide that binds to the
opioid receptors in the brain and body; synthesized in the
body’s nervous system.
What is exteroception?
The sense of the external world, of all stimulation
originating from outside our own bodies.
What is interoception?
The sense of the physiological state of the body. Hunger,
thirst, temperature, pain, and other sensations relevant to
homeostasis
What is nociception?
The neural process of encoding noxious stimuli, the sensory input from nociceptors. Not necessarily painful, and crucially not necessary for the experience of pain.
What are nociceptors?
High-threshold sensory receptors of the peripheral
somatosensory nervous system that are capable of
transducing and encoding noxious stimuli. Nociceptors
send information about actual or impending tissue
damage to the brain. These signals can often lead to pain,
but nociception and pain are not the same.
What is noxious stimulus?
A stimulus that is damaging or threatens damage to
normal tissues.
