WEEK 5 COMPLETED SET Flashcards
what is sensation
the process by which the sense organs gather information about the enviroment
what is perception
the process by which sensory information is selected organised and interpreted
what is transduction
the transformation of energy into nerve impulses a form our body can sense - coded in terms of intensity and quality
what are psychophysics
the study of how we perceive sensory stimuli based on their physical charcateristics
absolute threshold
the lowest level of a stimulus that we can detect 50% of the time
just noticeable difference
smallest change in a stimulus intensity that we can detect-
what doesjust noticeable difference depend on
intensity of new stimulation and level of stimulation already present
what is webers law
regardless of the magnitude of two stimulus. the second must differ from the first by a constant proportion for it to be perceived as different
what is the average weber fraction for weight
1/50
what is signal detection theory
sensation occurs when we judge whether a stimulus is present or not
what two processes contribute to signal detection theory
- initial sensory processes- sensitivity to the stimulus (signal to noise ratio)
- decision process- the individuals readiness to report detecting a stimulus when uncertin
what is attention
mental phenomena of concentration and its shifts in focus influenced by internal and external events and limited capacity
what is selective attention
allows us to select some inputs for further processing and ignore others- RAS and basal ganglia
broad bents theory of attention
bottleneck, early filtering mechanism, limited capacity channel (some you choose) where you resond or remember
cocktail party effect
suggests some information gets through the filter - even when we selectively attend to a conversation some information gets through- we are subconsciously monitoring conversations around us
errors of attention
change and inattentional blindess
what is divided attention
performing multiple tasks simultaneously, attention has a limited capacity, we think we can attend to many things but cant- ability is just speed at quick we can switch attention
what is the visable spectrum of light
400-700nanometers
characteristics of vision
image is inverted on the retina, which turns it into an AP,
cornea
direction and focusing, clear part of eye, curved dome which bends light
sclera
white part of your eye, refocuses light
choroid
muscle area attached to lens
retina
holds light sensitive cells, innermost layer of the eye where light is converted to nerve impulses
macula
contains fovea
fovea
part of the retina where light is focused most sharply, most concentration of cones
pupil
opening that lets light in
optic nerve
transmits impulses from the retina to the rest of the brain
eye muscle
one of 6 muscles that rotate the eye
lens
transparent disk that focuses light rays for near or distant vision
iris
coloured part which controls pupil
blindspot
point of no cells where info enters the brain
myopia
nearsightedness. focus point is before the retina
hyperopia
farsightedness. focal point is after/beyond the retina
rods
low light, monochromatic, peripheral vision, use rhodopsin which light bleaches causing fatigue
cones
bright light, colour, central vision and fine detail
gaglion cells
many rods connect to one
one cone connected to many ganglion
what is an optic chaism
where the two sides of vision cross over
path of vision
left side from left eye stays on same side but left side from right eye crosses over- visa versa
simple cells
in visual cortex- respond to light of a specific orientation at a particular location- respond to certian edges at certain degrees
complex cells
specific orientation but less dependant on location
feature detector cells
lines and edges (simple and complex cells), length of lines, shapes, movement colour etc
which visual cortex is movement in
V5
which visual cortex is colour in
V4
trichromatic theory of colour vision
colour vision is based on sensitivity to three primary colours, consistent with the three types of cones in your eyes, explains colour blindness (red, green, blue)
opponent process theory of colour vision
colour vision as a function of complementary opposing colours red vs green blue vs yellow black vs white
what are the three types of colour blindness
mono, di, and trichromacy
what is the most common cause of colour blindness
genetics, more common in males, faulty cone development
what is cateract
blurry vision, lens issue
what is glucoma
fluid pressure damages rods, peripheral vision loss
what is macular degeneration
less treatable due to age, central vision loss, causes blurred vision
what is diabetic retinopathy
increasingly patchy loss of vision, due to diabetes
what is childhood blindness
due to genetics
what is motion blindess
inability to perceive motion or stitch together incoming images
what is visual agnosia
inability to recognise objects despite normal ability to describe shape and colour
what are cortical blindness and blindsight
cortically blind people asked to idenitfy shapes and locations but some people claim they cant see so cant however can perform tasks at more than chances levels and are better than other blind types
what is the cause for blindsight
enough information is processed to have some sort of insight vision or collicular pathway can allow some visom
