Module 2 - Perception and Neurophysiology Flashcards
Sensation
receiving sensosy information from the environment
Perception
the interpretation of the information, assigning the information a meaning
How do we determine colours?
colours are determined by the different wavelength of light
- long nm = red
- short nm = blue
How do we determined if the colour is dull or bright?
The amplitude of the wavelength determines whether the colour is dull or dark
- longer wavelength means the brighter the colour
Cornea (outer layer)
Transparent layer in front of the eyes that bulges out
What is the process cornea is involved?
this structure of the eyes is involved in focusing an image
- an image falls in the back of the eyes, into the photoreceptors and triggering them (wants image to be as focus as possible)
Choroid (middle layer)
a structure in the eyes filled of blood vessels that bring oxygen and nutrients to the eyes
How does the choroid structure function?
this structure runs not around but covers the part where the cornea will not be disrupted
- so main purpose of the choroid structure is that blood vessels in here provides nutrients to the eyes and generates waste (not in cornea)
As there are no choroid structure in the cornea; How does cornea get nutrients and blood supply without disruption of visual?
There is a structure behind the cornea called the ANTERIOR CHAMBER which is a clear fluid that functions like blood as its function is to provide nutrients to the cornea to keep it alive and as well as generating waste
Vitreous humor (inner layer)
the inside chamber of the eyes that gives it shape
What is the purpose of vitreous humor?
it provide nutrients to all parts of the brain that the choroid does not reach
Iris (inner layer)
a muscle which controls the pupil and is the colours we see in the eyes
- so when the pupil is dilated more light gets into the eyes and if pupils are constricted less light gets into the eyes
Lens (inner layer)
behind the iris, this is attached to muscles which is a structure that changes it shape through engaging in the process called ACCOMODATION
Accomodation
the process where the lens changes it shapes to allow the focusing of objects near and object far
Critical period
the maximum amount of time to recover from the loss of a sensory system
- if defects not fixed by critical period, it will not be able to reverse action
e.g. congenital cataract
Retina
sheets of cells, these are the photoreceptors (rods and cones)
Bipolar cells
are one of the main retinal interneurons and provides the main pathways from photoreceptors to ganglion cells
i.e. the shortest and most direct pathways between the input and output of visual signals in retina
What happens if cortex is damaged?
when cortex is damaged, it causes less catastrophic impairment that are far more mysterious
e.g. people with damage in cortical vision
What happens if subcortex is damaged?
when part of the subcortex is damaged, the impairment are catastrophic but not mysterious
e.g. damage certain areas of subcortex can cause blindness
Dorsal stream
WHERE is the dorsal pathway which goes into the parietal lobe (important for knowing where an object is in space)
Ventral stream
WHAT is the ventral pathway which goes into the temporal lobe (important for knowing what the object is)
What system is the retinal ganglion associated with?
associated with both ventral and dorsal systems
Receptive field
the area of the retina which when stimulated by light causes a change in the neural activity of the cell
lateral inhibition
the capacity of excited neurons to reduce the activity of their neighbours (inhibits about 10% firing rate)