Sensation and Perception Week 5 Lecture 1 Close Up of Retina (February 3, 2015)
- The rods and cones of the retina collect the light
- The light comes through the retina, and lands on photo-pigments (rods and cones)
- The photo-pigments absorb the
Sensation and perception week 1-1
Transduction: changing energy (stimulus) from one form to another.
Light is electromagnetic energy needs to be converted to electrical impulse
Sound is mechanical energy converted to electrical impulse
Phoneme (speech sou
Vection = induced self-motion illusion. Visual system tends to assume that the small thing is the
thing that is moving (i.e. when large clouds move past the moon, it appears as though the moon
There is an illusion
Sensation and perception week 2-1
Inhibitory neurotransmitter: GABA when its picked up, it slows the rate of firing action
Valium a drug used to calm people down when their anxious. It basically tricks the perceptual
system into thinking its p
Sensation and perception week 1-2
Action potentials are always the same size all or nothing. Cant have a big action potential or
small action potential. But the frequency of action potentials can increase/ decrease. If something
is too intense, the cell w
Senile miosis: weakened/ constricted iris at old age.
The iris has melanin in it. It gives colouring to the iris. Blue eye = not very much melanin, darker
eyes = darker colour (like brown or black). Some people dont make melan
Sensation and perception week 2-2
Sensitivity: H FA the bigger the number the greater the sensitivity.
Magnitude estimation/ scaling
How does perceived intensity increase as a function of actual physical intensity? (i.e. first
intensity is 10, and then th
Physiology of the ear
Pinnae: The part of the ear that can be seen from the outside, it gathers in sound.
Pinnae are important in sound localization. If we didnt have pinnae, it
would be hard to know where the soun
Sensation and perception week 4-1
Rhodopsin cant absorb red very well because it is red.
Disorders of the retina
Detached retina: most common cause is getting hit in the
head really hard. Can also get it if you are in a traffic accident. The
Horizontal, bipolar, and amacrine cells are involved in lateral inhibition.
Mach bands is a perceptual illusion produced when there is a black area beside a white area. At
the boundary between the two spaces the white looks wh
Gestalt grouping principles (part of low level vision)
One of the simplest grouping principles is called grouping by proximity. A grid of dots can be
viewed as a bunch of vertical lines of dots (because the dots are a lot clo
Sensation and perception week 5-1
One pathway takes you to the tecto-pulvinar system all of them are magno fibres. It deals with
localizing things in space. Not part of the visual system that we are acutely aware of.
Superior colliculus (10% of fibres go
Contrast = difference in brightness/ sum in brightness (i.e. the high bar minus the low bar)
Spatial frequency: how close together the lines are in an image.
Cycle: a light area and dark area.
Fouriers insight: any complex fun
Sensation and perception week 6-1
Damage to parietal cortex results in hemi-spatial neglect. Right parietal damage is associated
with this. Makes it difficult for a person to notice things on the left side of the visual field.
Cancellation test, persons w
Sensation and perception week 8-2
Different shapes can produce the same retinal projection. The same shape can produce different
shaped retinal projections (shape constancy).
Shape constancy: We perceive the object to be a rectangular
door opening but, if
Most of the colours we see are mixtures of wavelengths desaturated colour. A pure colour is
monochromatic (one wavelength, saturated).
Rod monochromats: See black, white, shades of grey. They only have rods, rod
Sensation and perception week 7-1
-sense of how far away something is
-retina is flat (2D), world is 3D
Close image = large visual angle
Far image = small visual angle
Big object or is it just close?
Small object or is it j
Sensation and perception week 11-2
If you dont exercise or eat well youll experience hearing loss as well. A person who takes good
care of themselves is probably going to have better hearing. Older people dont realize they are
losing their hearing they th
Inner hair cells are less numerous (only 3000) but they are the ones doing the job of pitch
Outer hair cells (about 12000 per ear) are attached to the basilar membrane, they help lift up the
membrane to make its m
Sensation and perception week 12-1
Attack: the way the sound hits.
Decay: the way the sound fades away.
Cues to location of a sound (2 dimensions)
1. Inter-aural time differences: If something is coming from the right, it will hi
Sensation and perception week 9-2
Need good depth perception in order to coordinate your limbs.
When you are using vision to help balance yourself, you are using optic flow. If you get
misleading optic flow you will fall.
As something is approaching you i
Different types of olfactory neurons connect to different types of glomeruli. Its not clear why it is
we smell the certain quality that we do. Sometimes we have things that are chemically similar
but smell different.