Sensation Flashcards
What is transduction
When sense organs receive sensory info and send a signal to the brain.
All the types of sensory information
where do they go
Vision, hearing, taste, touch - thalamus (relay center)
Smell - Amygdala + Hippocampus
What is sensory adaptation
What is sensory habituation
Adapt to a constant stimulus.
eg: if ur in a dark room for a long time, eyes will adapt eventually and you can see better
What we perceive is determined by what sensations activate our senses and by what we focus on perceiving. Usually involuntary
eg: cock-tail party effect. Focus on perceiving our name.
What are the steps to vision - basic steps (don’t explain in detail)
1) Gathering light - Light that is reflected of objects is gathered by the eye.
2) In the eye - Light goes through the cornea –> pupils –> accommodation –> retina.
3) Transduction - Cones and rods fire –> bipolar cells fire –> ganglion cells to fire –> optic nerves –> thalamus –> visual cortex
4) In the brain: Visual cortex processes the image.
Explain step 2 in detail of steps of vision What is the cornea? What does it do What is the pupil - what does it do What is accommodation What is the retina
Cornea - Protective covering that helps focus the light.
Pupil - Has muscles called ‘iris’ which dilate to let more light in and close to let less light in.
eg: dark room, pupils dilate to let more light in to see better.
Accommodation - processing of the pupil adapting/accommodating the incoming light.
What is the retina - part at the back of the eye that receives the light. Always produces an inverted image.
Explain transduction stage in detail
What are cones
What are rods
Which outnumbers which
Which part of the retina are the more cones and more rods
Explain ganglion cells, optic nerves, etc
Which part of the thalamus receives the sensory information
What does the visual cortex do
where is it located
Cones are cells activated by color
Rods that respond to black and white.
Rods outnumber cones in a ratio of approx 20:1
At the center of the retina - there are no rods and only cones
As you move to the periphery - no cones and only rods.
When cones and rods are fired - they trigger bipolar cells to fire which trigger ganglion cells to fire.
Several ganglion cells together form an optic nerve which sends an impulse to the Lateral Geniculate Nucleus (part of the thalamus)
The LGN then sends the impulse to visual cortex which processes the visual information and is located at the occipital lobe.
What is a blindspot
Point at which there are no cones or rods since its where the optic nerve exits the retina.
What is the optic chiasm
Point at which opptic nerves from left and right eye cross.
because right optic nerve goes to left hemisphere of brain and vice versa.
How does the visual cortex process the image
who gave it
Interprets the various features of the image and puts them together
There are many feature detectors present which are activated (eg: curved lines, sleeping lines, straight lines, etc)
Given by david hubel and torsten wiessel.
Who gave the trichromatic theory (color vision)
What is it
criticism
Young Helmholtz
There are 3 types of cones in the retina (red, blue, green) which are activated in different combinations to produce all the colors.
criticism: Can’t explain after images and color blindness.
What is colour blindness
2 types
Inability to see a certain colour
Dichromatic - can’t see red/green shades or blue/yellow shades
Monochromatic - can only see shades of grey.
What is the opponent process theory
how did it explain colour blindness
how did it explain after images.
The sensory receptors in the retina come in pairs - reg/green, yellow/blue and black/white
When one is stimulated, its pair can’t fire
Colourblindness - when you are missing one pair of receptors, you can’t see that colour
After images - if you stare at eg: red, object for a long period of time, it tires the red receptors and then when you look at something else, red’s receptors can’t fire and its pair (green) fires.
Basic properties of sound
how does it travel
what is amplitude
what is frequency
Travel as sound waves which are vibrations in the air that are collected by the ear
amplitude - volume
freq - pitch
Process of hearing
scientific name of ear drum what are the 3 bones What is a cochlea What is the basilar membrane What is the organ of carti
Waves travel down ear canal
Reach the ear drum (tympanic membrane)
The ear drum vibrates as the sound waves hit it.
Attached to the ossicles (hammer, anvil, stirrup)
The vibrations of the ear drum pass through the 3 bones to the Oval window
The oval window is attached to the cochlea which is a snail like shell filled with fluid
As the oval window moves, the fluid moves
The basilar membrane is at the floor of the cochlea and has hair cells that are connected to the ‘organ of corti’
The neurons are activated by the movement of the hair cells
Transduction - Impulses transmitted to brain via auditory nerve.
What are the 3 parts of the ear
the body parts they include
External - ear drum, ear canal
Middle - 3 bones
Internal - cochlea
What are the 2 pitch theories
Frequency - the rate of hair cells firing depends on the freq of the sound
Place - when hair cells vibrate they respond to different frequencies.
Some part of hair cells respond to high pitch and some parts of the hair cells respond to low freq.
What are the 2 types of deafness
what is harder to treat.
Nerve (sensorineural) deafness - hair cells in the cochlea are damaged by loud noise usually. More difficult to treat
Conduction - something wrong with the system of conducting sound to cochlea - ear canal, ear drums, 3 bones, oval window
Need to replace the damaged part to treat.
What is the vestibular sense
A body position sense
How body is oriented in space. Fluid moves canal rapidly. Can cause nausea/dizziness an the brain gets confused by the impulses.
What is the kinesthetic sense
A body position sense
Tells us the overall position of the body and gives feedback about the orientation of the body - limbs, etc.
Dancers and athletes need a high kinesthetic sense.
Process of smelling
Moles of smell - go into the air and diffuse throughout.
Those molecules enter the nose and go to the mucus membrane.
The mucus membrane has over 100 receptors which absorb the molecules and are called the olfactory receptor cells
olfactory receptor cells linked to the olfactory bulb which is connected to nerve fibers which send the impulses to the amygdala + hippocampus.
What are the 5 types of taste buds to taste what
Sweet salty sour bitter umami (ajinomoto)
Process of taste
What are papillae
papillae - Bumps on the tongue which are densely packed with taste buds.
Process of taste
Papillae - absorbs chemicals
tastes food for intensity
Impulses send to the thalamus.
Touch
what do receptors do
what are 2 types of receptors
Receptors - information about pleasure, pain, and temperature
Cold fibers - Receptors that detect cold temp
Warm fibers - receptors that detect warm temp
How do the amt of nerve endings in diff places affect what we feel
Higher the concentration of nerve endings in that region, the more sensitive that region is.
What is t he gate control tehory
States that pain a high priority msg compared to temperature, pressure, etc.
When a high priority msg is sent a ‘gate’ swings open for the high priority msg to t he brain and closes for low priority msgs
What are endorphins
Neurotransmitter - pain relief
Shut the gate
similar to morphine
