sensation
perception
what we have to create meaning (like building blocks)
combination of sensations pkus prior knowledge to interepret sensations and make meaning
transduction
place where sensations are translated to elctrochemical signals
bottom up processing
neural processinga t sensory organs.
senses–> brain
info from environemnt
top down processing
- individually unique from expeirinces
- combinig info with prior understanding of the world to create perceptin
gestalt psychologis
20th century
belived were born with predisposed ways of organziing infomation so its useful
interested in bottom up provessing
gestalt priciples of organization
1 figure grabd
2 principle of proximity
3 similiarty
4 closure
5 good coninuation
6 common fate
anatomy of eye (be able to label it)
nearsighted vs far sighted
the retina
- rods and cones
- cones: fovea
- rods: images, sense movemrnt and location around retina
- dark adaptation: how you adapt to less light, as R and C adaptbi
bipolar and ganglion cells
bipolar
- interpet info by connections to several rods or one cone
- 1:1 for cone to bipolar cell ration
- into sent to ganglion cells
- infro from multiple rods sent to large ganglion (M cell)
info from one cone sent to small ganglion (P cell)
ganglion
- sees bits and pieces
- eventually the bundle of neurons makes the optic nerve
- organization allows for detetcion of edges
receptive fields
visual pathway to cortex (EXPLAIN diagram)
- both eyes see left and right visual fields
- primary VC or striate cortex
- light hits C and R (back of retina)–> biploar cells–> ganglion cells–>VC (occipital lobe) –> temporal lobe (ventral stream–what is it?) or parietal lobe (dorsal stream–where is it?) and to limbic system (how do you feel when you see object)
retinotopic organization and
-spatial organization of retinal images maintained through visual pathway
feature detectors, (complex and simple cells)
-special neurons that respond to speicifc stimuli in brain to detect edges, lines, angles, and movement.
- allow to see lines at diff angles in environemt (IN BRAIN)
-Hubel and Wisel (1960) nobel prize
-simple cells: lines at diff angles
- complex cells: respind to verticle lines in motion
two theories of colour
trichromatic
- comparing the activation of the different cones
- For example, when you see a blue car, it is because the car is reflecting short wavelengths to your eye, which activate the S-cones but not the M- or L-cones.
opponent process theory
- cells in visual pathway increase activation when recive info from one kind of come and decrease when they see a second colour
- colours are paired with complementary colours
- explains after images
- looking at one color for a long period causes those receptor cells to become fatigued. When they begin sending weaker signals, their opposing cells fire, sending signals that cause the perception of the opposing color.
three types of cones
- S cones: short light waves perceived by cones as blue
- M cones: medium wavelength periceved as green
-L cones: long wavelengths red/orange
recpetive fields
- ganglion cells have recpetive fileds
- help interpt where edges of images are
- center on vs center off cells
- when whole field illuminated, firing is sae
allsows for single cell to send variety of info about surface of object
monocular depth cues
- occlusion
- relative height
- perspective convergence
- familar size
- atmospheric perspectvies
- relative size
the ames room
- 1930
depds on assumption of relative hieght
room seems square isnt - cieling is not same height
bionolcular depth cues
- input from both eyes
- retinal dispartity: brain maeks comaprions between both eyes
- convergence: eyes move to focus on close objects, (movemnt intereped by brain)
Binocular cues create a three-dimensional image of the world one views. There are two types of binocular depth cues: convergence and retinal disparity.
sound
frequency: rate of vibrations
- pitch (high/low)
- meausred in cycles per second (hertz)
intensity (amplitude)
- loudness
- db (pressure meausre >100db human earto much
anatomy of ear (in order of how it travels)
- pinna
- tympanic membrane
- ossicles
- oval window
- cochlea
- basilar membrane (in cholea)
- to brain
cochlea
- transduction happens here
- fluid filled
-basilar membrane (sound waves cause membrane to move up and down-bends cilia on hair cells attahced ot membrain, brain recived excitatory message)
two theories of sound
place theory
- high pitch near oval window, low picth at far end
- cochlea has diff thickness as diff places
- location of firing on basil membrane helps us periceive pitch
20-2000 hz is natural range
frequencey throry
- more rapid firing = higher pitch
- neurons fire in sucession, spaced out = increase mesage
auditory pathway
basic pathway
- ear, brainstem, thalamus (MGN), temporal lobe,
0 simple sounds processed down, complex sounds processed in cortex
