Perception and neuropsychology Flashcards
What is the structure of the eye?
- Outer layer (cornea)
- Middle layer (choroid)
- Inner layer (Pupil, Iris, Lens, Vitreous Humor)
What is the function of the retina?
Involved in transduction, they take the energy and convert it into a neural signal.
What is the function of sensation?
Registering of sensory information by the brain
What is the function of perception?
Assigning a meaning to that sensory information
What is the function of cones?
Used for colour vision, day time photo receptors, high resolution
What is the function of rods?
Do not process colour, used at night time, low resolution
Are cones or rods more numerous?
Rods are more numerous
Where are cones found?
In the fovea
Do rods get gradually larger or smaller as you get further from the fovea?
Rods get gradually larger as you get further from the fovea
What is retinotopic mapping?
Point-to-point mapping of the external world onto our retina, lateral geniculate nucleus and V1
What is the function of the eyes receptive fields?
The receptive field is the area of the retina when stimulated by light causes a change in the neural activity
What is lateral inhibition?
Enhances contrast (makes things appear better)
What performs lateral inhibition?
The retinal ganglion cell.
What do rods and cones like to look at in the visual field?
Diffused light
What does the retinal ganglion like to look at in the visual field?
Spots
What does the Lateral geniculate nucleus like to look at in the visual field?
Spots
What does V1 like to look at in the visual field?
lines of difference
What is double dissociation?
Once info arrives at the primary visual cortex it splits into 2 pathways:
-Dorsal stream for spatial vision/ location (parietal lobe)
-Ventral stream for pattern perception (temporal lobe)
What happens when you damage your parietal lobe?
Unable to perform a landmark task
What is the Herman Grid illusion?
The dot in the intersection disappears because we are foviating.
What is the correct order for the waste station pathway?
- Eyes (optic nerve)
- Subcortex
- Cortex
What study did Mishkin and Ungerleider conduct?
Monkey object and landmark discrimination tasks, study suggested that when you damage your temporal lobe you are unable to perform an object task but able to perform a landmark task
What is apperceptive agnosia?
Damage of the ventral stream, failure of object recognition due to a failure of visual perception, poor matching and copying
What is Dorsal simultagnosia?
Damage to dorsal pathway, failure of object recognition due to a spatial perceptual impairment, can recognise objects but not more than one and cant tell you what is happening in an image but can name what is in it
What is ventral simultagnosia?
Damage to ventral stream, failure of object recognition due to a complex perceptual impairment, can recognise objects but not more than one