lecture 4 Flashcards
What is the process from sensation to perception
stimulus energy, sensory receptors, neural impulses, brain (perception)
can Perception change
Perception is subjective and can change
what does Pain perception depend on
Pain perception changes depending on what is expected
Pain ratings for the electrical shock were higher in the high-cue (high pain expectancy) trials than the low-cue (low pain expectancy) trials despite the shock being at the same level
what is Synaesthesia
Stimulation of one sense simultaneously produces another sensation in a different modality (senses can mix)
what is Grapheme-color synesthesia
¤ Seeing certain numbers or letters as certain colors (red twos and green 5’s)
¤ May be learned (studies show that it may be because we learn the alphabet with colours
what is our dominant sense/percept
Vision
what is the McGurk Effect
¤ Speech sound /ba/ simultaneously presented with visual speech sound /fa/ heard as /fa/
what is A multisensory illusion
change in auditory perception from visual input
is the mcgurk effect a A multisensory illusion
yes
what does the mcgurk effect demonstrate
¤ The integration of sensory information ¤ The power of visual input
¤ It over-rides audio input!
When we see, is there input into the eye or output from the eye
input into the eye
what is the Extramission belief
When we see, there is a ray that exits the eye onto an object (an output; false)
what is the experiment that proved that most people believe that the extramission is correct
Ask participants: How does vision work?
Tested three ways: 1.Computer graphics 2. Verbal descriptions 3. Verbal Reports
Results: The majority favoured a view of vision that had some variant of extramission belief that was found for all ways of testing
when people had education nohow vision worked, do they still believe in extramission
yep, not all but a good chunk of them
what is the difference between early and late visual processing
¤ Early visual processing ¤ Sensation ¤ Eyes and the optic nerve ¤ Late visual processing ¤ Perception ¤ Visual cortex (Occipital lobe)
what are the 4 steps of Early visual processing
- Light waves enter the eye, focused onto the retina
- Photoreceptors in the retina convert light to electrical activity
- The electrical signal is sent to bipolar cells and then to the ganglion cells
- The electrical signal is sent to bipolar cells and then to the ganglion cells
4
what is the retina
A thin layer of tissue at the back of the eye
what are the different photoreceptors
- Light waves enter the eye, focused onto the retina
¤ A thin layer of tissue at the back of the eye - Photoreceptors in the retina convert light to electrical activity
are there the same number of photoreceptors as ganglion cells and other cells in vision
NO
Millions of photoreceptors in each retina converge onto 100 x fewer ganglion cells à optic nerve à brain
Millions of photoreceptors in each retina converge onto 100 x fewer ganglion cells à optic nerve à brain
what does this mean
the message from the eyes to the brain is compressed
You don’t ‘see’ everything that is out there in the world
where are Photoreceptors located
back of the retina (farther from the ‘world’)
where are Ganglion cells located
are at the front of the retina (closer to the ‘world’)
Cones (high light level photoreceptors) are mostly where
in the fovea
what is the fovea
¤ A small area on the the central part of the visual field
¤ Most of our detailed vision in the center of our visual field
where are Rods
mostly outside of the fovea, in the periphery
what are the characteristics of periphery
Peripheral vision is less detailed and better for seeing at night