2. same area of visual space – same region of the brain
Οπτικό Πεδίο, 2 μάτια:
same area of visual space – same region of the brain
S12
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3. VISUAL HEMIFIELD ‘monocular crescent’ temporal hemi-retina
nasal hemi-retina

4. VISUAL PATHWAY only nasal fibres cross over optic nerve
= ‘decussation’
optic nerve
chiasm
optic tract
lateral geniculate nucleus
optic radiation
primary visual cortex
‘Meyer’s
Loop’

6. - 90% of the fibers innervate the LGN - the remaining 10% are more than the ones found in the entire auditory pathway - superior colliculus & pulvinar nucleus: play a big role in visual attention - the retino-collicular pathway belongs to a more primitive visual system

7. - Schneider (1969): V1&V2 lesion or ablation of input fibers to SC in hamsters trained in a localisation and a discrimination task (double dissociation) - “blindsight”: subcortical pathways and/or processing in extrastiate (= beyond V1) cortex?

8. Rafal et al. 1990: hemianopic patients (V1 lesion) were slower in eye-movement responses (but not in button-presses) when a distractor was presented to the blind hemifield (competing eye-movement signals are generated in the SC that still ‘sees’ the distractor)

10. lateral geniculate nucleus of the thalamus (LGN)

11. 6 distinct layers receiving monocular input: 4 P(arvocellular) - μικροκυτταρικές στοιβάδες (χρώμα, σχήμα) 2 M(agnocellular) - μεγαλοκυττατικές στοιβάδες (κίνηση)

13. for a given eccentricity, M-cell receptive fields are 2-3 times larger (i.e. worse spatial resolution) than P-cell receptive fields
P pathway: colour, spatial detail (detect changes in spatial (space) domain)
M pathway: motion & flicker (detect changes in temporal (time) domain)

14. equiluminance/isoluminance (M-system ‘blind’?)
equiluminant grating: the red and green stripes are of equal luminance, i.e. the grating is defined by colour-contrast alone

15. The M-system has a high temporal resolution but can only detect luminance-contrast and so the equiluminant stimulus is seen only by the P-system (that can detect colour-contrast) which has a poor temporal resolution (but very good spatial-resolution) and thus leads to an impaired processing (& thus perception) of the motion-information.