Intro to the senses Flashcards
5 special senses
vision, hearing, equilibrium, taste, and smell
4 somatic senses
touch, temperature, proprioception, nociception (pain and itch)
Receptors
cells that convert stimuli into electrical signals
what is the conversion from stimuli to electrical signals called?
transduction
what are the receptors for sensory systems?
neurons
what are the receptors for hearing
non-neuronal epithelial cells
receptor potential
this refers to the graded change in membrane potential caused by the conversion of stimulus energy
what happens after the receptor potential is triggered?
it may cause the receptor to release a neurotransmitter or if the receptor is a neuron, it may release an action potential
adequate stimulus
form of energy that the receptor is most responsive to
example of adequate stimulus
thermoreceptors are most sensitive to temperature
chemoreceptors
respond to specific molecules or ions
mechanoreceptors
respond to mechanical energy like pressure, vibration, gravity and sound
thermoreceptors
respond to temperature
photoreceptors
respond to light
receptor threshold
the weakest stimulus that illicit a response
perceptual threshold
the weakest stimulus that will cause a conscious perception
what is the basic structure of a sensory system
primary neurons are the first neurons in the system
primary neurons synapse on the secondary sensory neuron
the secondary neurons synapse on the tertiaries
what is the value of convergence
this means that the tertiary neuron is able to receive all the information from the several individual primary neurons
why do we care about this value of convergence?
because it allows for efficient communication
stimulus modality
sensory neurons carry information about what type of information is being carried, like if it is light, touch, or sound
Modality by labeled lines
this basically means that the type of stimulus it is can also be identified by which types of axons carry them.
activity from neurons in the visual pathway mean light
activity from neurons in the auditory pathway mean sound
phasic cells
respond to brief changes but then they stop after it becomes steady
tonic cells
unlike phasic cells, they maintain their activity when the stimulus is steady, signalling the present level
phasic-tonic cells
this is a combination of the 2 where they react in response to a change but don’t return all the way to zero but also carry information about its steady level
are retinal cells phasic or tonic?
they are phasic
what is an advantage to phasic signals
they make communication more efficient because our world is fairly stable we only really need to be paying attention to the changes that happen
What are spatial changes? Why are they also efficient
these are differences between neighboring regions in space. it is able to tell the difference between one patch of area and one directly near the first.
if we pinch our skin- we are able to feel the pinch and also where we are not being pinched due to these spatial changes
what is another name for spatial changes
contrast
what is the name for the locations where there is strong contrast
edges
how can sensory system make edges more noticeable?
by lateral inhibition
lateral inhibition
cells can either inhibit their neighbors or inhibit the cells their neighbors excite
what is the path to run for most sensory pathways
to the cortex via the thalamus
which sensory pathway does not cross the thalamus?
the olfactory pathway bypasses thalamus and goes directly to the brain from the nose
what are equilibrium pathways?
these are pathways that go from the thalamus to the cerebellum
why does it make sense for equilibrium pathways to go to the cerebellum as opposed to the cortex
because the cerebellum has been known to strongly influence balance
Fill in the blank.
Sensory Processing is ________.
inference.
why is sensory processing inference
because our perceptions of the world is always educated guesses and our sense data is incomplete and ambiguous so the bran has to infer
What does the kanizsa illusion reveal about our brains?
it shows that the brain mistrusts coincidences. our brain will see overlapping triangles because of the perfect alignments of the Vs and pacman figures
