Wk4 Space & Action Flashcards
(80 cards)
perception drives action, but also action__
preparation can drive perception
what are basic characteristics of visual information at the primary visual cortex? 2
simple features eg. orientation
retinotopic
what are the two ‘sides’ of visual field on the retina in each eye
nasal and temporal
what are the two visual pathways from the retina?
retinotectal pathway
geniculostriate pathway
which visual pathway would be involved in reflexively detecting sudden visual stimuli?
retinotectal pathway (from the retina to the superior colliculus on the tectum/midbrain)
what are the two pathways within the geniculostriate visual pathway? how are they oriented? what type of processing does each concern?
magnocellular (Dorsal): fast efficient processing
parvocellular (ventral): slow effortful processing
where does the dorsal stream terminate?
parietal lobe
where does the ventral stream terminate?
inferior temporal lobe
at what level (biologically and developmentally; 2) do dorsal and ventral streams start?
at the retinal level
in place in embryo
what type of cells have been found to diverge into M and P types in macaque monkey embryos?
retinal ganglion cells
where are parvo cells found in the retina? how about magno cells?
magno = peripheral parvo = closer to fovea
How is information from the left and right eyes organised in the LGN, with M and P cells ?
M cells connect to two layers of LGN
P cells connect to 4 LGN layers
contralateral and ipsilateral connections are interweaved at each layer, meaning information from both visual fields is combined
midget and parasol cells are a.k.a __
parvo cells and magno cells, respectively
what are particular properties of visual information in parvocellular pathway? 4
color
high spatial resolution
slower
sustained response
what are particular properties of visual information in magnocellular pathway? 4
monochrome
low spatial resolution
faster
transient reponse
which type of visual cells are used more at night?
magno cells
which type of visual cells detect higher details? what is the functional property that allows this?
parvo
smaller receptive fields
which type of visual pathway cells detect motion better? what is functional property that allows this?
magno
larger receptive fields
what type of neurological dysfunction may explain dyslexia? what functional deficit does it explain?
reduced mangocellular density in dyslexic autopsies
impaired ability to read and visually flick between bits of information
what could the failure of giving coloured glasses to dyslexics indicate about neurological pathways?
we do more with vision than relying either of the M and P pathways
what was a hypothesis about how visual processing could explain social deficits in autistic infants?
they might have trouble putting together high and low spatial contrast images of faces due to magnocellular dysfunction, leading to poor social development
at a higher cognitive level, the magnocellular pathway primarily allows us to ___ by coding for ___
work out where things are
location
what evidence links selectivity for orientation and visual guided action in macaque studies?
neurons in area 7 (parietal) were selectively activate for 45 deg orientation and direction of reach. when lesioned, results were poorly directed reaches
by 64 weeks or 16 months 3 dimensional reach profiles are almost as refined __ . showing?
as adults are
selectivity is fine-tuned early in development