apysch c6--sensation

how do our senses work?

• most of our senses work the same: our sensory organs receive stimuli, these messages go through transduction, which means the signals become neural impulses. then, the impulses go to the thalamus (part of your brain) and finally to different parts of the brain

sensory adaptation

• why do we stop feeling clothes after we put them on? sensory adaptation! we are used to the stimuli after a minute or so and then forget about it. it also has to do with sensory habituation, the idea that our focus level determines sensation perception

cocktail party effect

• you are talking with someone and hear your name across the room, thus you switch attention spans

how do sensation and perception relate to each other?

• continues to be debated, but our senses activate our perception and thus our way of understanding the sensation

prosopagnosia

you can’t recognize faces

step 1 in vision (gathering light)

• wavelength: light reflects of objects. a red shirt reflects red light, black reflects no colors of light, and white reflects all colors of light

• the wave’s amplitude is also important because it determines the intensity of a color

step 2 of vision (within the eye, diagram pg. 45)

• light goes through cornea and focuses, then through pupil. a pupil and contract and dilate to let more or less light in

  • light that enters the pupil is focuses by the lens which focuses light on the retina

  • nearsightedness/farsightedness occurs when the lens cannot focus properly

• when light passes through the lens, it is flipped and inverted

vision step 3 (transduction)

• transduction refers to the translation of incoming stimuli into neural signals, not just a vision thing!

• the first layer of cells in the retina are photoreceptors. cone cells are activated by color and rod cells are looking at black and white. cones are concentrated in the center of the retina and on the side are the rods

• if enough in the first layer fire, they activate the next layer, bipolar cells, and then ganglion cells are activated, which enter into the optic nerve

• the spot where the optic nerve and retina connects have no cones so it is your blind spot

step 4 of vision (in the brain)

• the visual cortex of the brain is located in the occipital lobe (flashback to previous units)

• visual cortex of brain receives impulses from the cells of the retina and creates perception of visual images

theories of color vision—trichromatic theory

• we have red, blue, and green cones in the retina which combine to create everything we see

• does not explain afterimages (if you stare at something for a while, u can see it in a different color even when you look away) and colorblindness. people with dichromatism cannot see red/green or blue/yellow, and monochromatism means that you only see shades of gray)

opponent-process theory

• sensory receptors come in pairs (red/green, yellow/blue, black/white) and if one sensor is working the other is not firing, which makes a lot more sense

what are sound waves (pg 47)

• sound waves are formed by vibrations and have amplitude, frequency, loudness, and pitch (determined by frequency)

sound localization

• sound localization is how when info reaches our brain, we can determine which side it is coming from

pitch theories—place vs. frequency

• place theory holds that hair cells in the cochlea respond to different frequencies of sound based on where they are in the cochlea, sense pitch

• frequency theory holds that we sense pitch because hair cells fire at different rates in the cochlea

conduction deafness vs. nerve deafness

• conduction deafness—sound is not conducted to the cochlea correctly

• nerve deafness (sensorineural deafness)—hair cells in cochlea are damaged by loud noise, harder to treat because we do not know how to get hair cells to come back

how does touch work in our bodies

• nerve endings all over our bodies response to the intensity, temperature, pressure, etc.

• if touch or temp. receptors stimulate sharply, we have pain receptors fire

• gate control theory says that some pain messages have higher priority than others so the gate will “open” for higher priority things: ex: scratching an itch and you forget about the itch while you scratch

what are chemical senses

they respond to chemicals, and not energy. two are taste and smell

taste/gustastion

• pg 49 for pic

• taste receptors are on our palpillae (lil bumps on your tongue)

smell

• pg 49 for pic

• receptor cells absorb molecules of substances, link them to the olfactory bulb and send the info to the brain

• smell is the only impulse where information goes right to the amygdala and then hippocampus

vestibular sense

• semicircular canals in our inner ears give us feedback about body orientation. these canals are filled with fluid which moves as your head moves. when on a roller coaster, you get nauseous because the brain is confused!

• basically how our body is oriented in space

kinesthetic sense

• kinesthesis gives us feedback about position and orientation of specific body parts which helps us know where parts of our body are in relation to each other

pg. 50 diagram