Sensory and perception (3C) Flashcards
Sound adaptation
- the muscles around our ears can contract so less of the sound wave enters the ear
- Our ears become less sensitive to continuous noises
- our brains filter out sounds that are not important
Cocktail party effect
The brain picks up on relevant sounds, even in a noisy environment
General Loudness
Louder sounds seem close
Loudness in each ear
The ear closer to the sound hears a louder noise than the ear farther from the sound
Timing
Sound waves will reach the ear closer to the source of the sound before they reach the ear farther away
Development of hearing
Babies can hear before they are born
- ability to recognize and respond appropriate to sounds develops in the first few months after birth
- infants prefer speech (especially mom’s) to non-speach
Deafness
Loss of hearing (partial or complete)
- can be genetic, caused by infection, physical trauma (headphone use), exposure to toxins, high doses of common medications such as aspirin
Tinnitus
Ringing in the ear
- due to abnormalities in the ear
- one of every 200 people experiences tinnnitus
Hearing loss - cochlear implant
Medical devices that are implanted in the ear and wired to the nerves that send sound information to the brain
How does the eye work?
- Light enters the eye
- Muscles in the iris adjust pupil size to control the amoung of light allowed in
- Muscles also change the shape of the lens to bring the object into focus
- The lens focuses light on the retina
Iris
Coloured part of the eye that adjusts the pupil size to control the amount of light allowed in
Retina
Multi-layered sheet of nerv cells
Photo receptors
Sensory receptor cells for vision called rods and cones, located in the retina. Which transduce the light waves into a neural impulse
Rods
- used to detect light
- used for periphery and night vision
- not as acute as cones (fuzzy vision)
- Many more rods that cones (over 100 million)
Cones
Used for central and colour vision
Very acute (very clear)
- the fovea - is the center of the retina where all the cones are found
- not as many cones (4.5 to 6 million)
Hue
The experience of colour based on the wavelength of light; green, blue, red, and other colours
Saturation
Purity of color; how bright or vivid it is
Brightness
How much light is reflected from the object
Trichromatic Theory
There are three different sensors for colour and each type responds to a different range of wavelengths of light
- we see more than three colours, which the variety of colours that arise form combine three colours
Opponent process theory
Colour pairs work to inhibit one another in the perception of colour
- retinal ganglion cells are arranged in opposing cells; red-green, yellow-blue, black-white
- support for this theory - we cannot see mixes of certain colour; reddish green or bluish yellow
Colour blindness
Most people who are colour blind cannot distinguish between red and green
Visual fields
The optic nerve carried messages form each eye (visual field) to the visual cortex (occipital lobe)
Visual pathway
Th optic nerve contain the axons of 1 million ganglion cells that exit the eye via the blind spot and project to the thalamus
- from the thalamus, neurons project to the visual cortex
“What” pathway
Help us determine the identity of an object
Visual agnoisia
Damage to the “what” pathway; cannot visually recognize objects
Propopagnosia
A form of visual agnosia in which people cannot regonizes faces
“Where” pathway
Locating objects in space
Hemi-neglect
Damage to the “where pathway; people ignore on side of ther visual feild
- eat food only one side of the plate
- people with damage to the right side of their “where” pathways neglect the left side of their visual feild
