The perceptual process + neural firing
Stage of perception when you 1st have conscious awareness of an object
What is perception?
The perceptual quality related to the amplitude of a light wave
What is brightness?
When retinal changes shape
What is isomerisation?
The region on the receptors in which stimulation causes that cell to change its activity
What is the receptive field?
Detect the orientation of lines and location
What are simple cells?
Knowledge-based processing
What is top-down processing?
The part of the eye that contains only cones
What is the fovea?
Contained in the rod and made of retinal and the opsin-protein strand
What is Rhodopsin?
Type of receptive field for bipolar and ganglion cells
What is a centre-surround structure?
Located in the thalamus and is the first place the visual information stops as it leaves the eye to the primary visual cortex
What is the Lateral Geniculate Nucleus?
The smallest amount of stimulus energy necessary to detect a stimulus
What is the absolute threshold?
The two types of photoreceptors
What are rods and cones?
Photoreceptors with greater visual acuity
What are cones?
Black squares but grey dots are seen in the intersections when not looking directly at the cross-sections but when looking directly at the junctions, they disappear
What is the Hermann Grid illusion?
Layers 1 and 2 of the LGN responsible for movement. Receives m ganglion cells
What is magnocellular?
These are the steps in the perceptual process which involve knowledge
What is processing, perception, recognition and action
When the eye doesn't focus light evenly so there is blurry vision (affects the cornea)
What is astigmatism?
The process when retinal and opsin pull apart - so named because they become colourless
What is bleaching?
For this particular type of centre-surround arrangement, any light shining on the centre part of the receptive field will excite the cell but any light on the outside edge will inhibit firing
What is on-centre, off-surround?
What are p ganglion cells?
This is Gustav Fechner's method that has the least bias
What is method of constant stimuli?
A dense, cloudy area that forms due to protein clumps and prevents light from going through to the retina leading to blurry vision (affects the lens)
What are cataracts?
When we shift to nighttime vision but the perception of brightness increases for specific wavelengths due to differences in threshold curves
What is the Purkinje shift?
This process allows ganglion cells to highlight edges
What is lateral inhibition?
We know this process occurs in the cortex and not the LGN because it shows intra-ocular transfer
What is selective orientation to adaptation gratings?