PSYCH 2220

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PSYCH 2220 Sensation Perception I Lecture 4
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Keywords for lecture 3
bipolar cells (excitatory and inhibitory types),
retinal ganglion cells, on-centre off-surround,
off-centre on-surround, concentric organization,
spontaneous firing rate, excitation, inhibition,
retinal ganglion cells as edge detectors, Mach
bands, "scalloped illusion", simultaneous
contrast, seeing (or not seeing) gradient (4
retinal ganglion cell demonstrations) information
passing down the optic nerve, optic chiasm,
magnification factor, partial decussation,
thalamus, cortex, brainstem, olfactory
'swelling', visual 'swelling', hearing and
balance 'swelling', lateral geniculate nucleus of
thalamus (perception), pupil control nucleus,
superior colliculus (fast eye movements),
vestibular nucleus (slow eye movements and
orientation)
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Keywords for lecture 3 (contd)
sustained and transient cells, cortex (cortices),
cerebral hemispheres, cerebellum, sulcus (sulci),
gyrus (gyri), functional localization over the
cortex, primary sensory projection areas,
association cortex, frontal, parietal,
inferotemporal, visual cortex, area 17, Brodmann,
retinotopic map,
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Lateral geniculate nucleus of the THALAMUS
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Organization of the lateral geniculate of the
THALAMUS (1)
Parvocellular layers (3- 6)
Magnocellular layers (1- 2)
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6 5
4 3 2 1
6 5 4 3 2
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Injection of tracer to left eye
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CORTEX
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Magnification factor when looking at the centre,
each letter uses the same amount of cortex
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David Hubel
Torsten Wiesel
Plotting the receptive field of a simple cell..
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• Hubel Wiesel described three types of cells in
  the cortex
• simple
• complex
• hypercomplex
• from their responses all vision is built up.
• They received a NOBEL PRIZE for this work.

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SIMPLE CELLS are orientation tuned...
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Visual cortical cells are orientation tuned
Response
preferred orientation
Orientation
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Complex cells
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video about cortical cells
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Tuning for orientation of bars Tuning for width
of bars
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Activity profile while viewing the test stimulus
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Activity profile while viewing the adapting
stimulus the amount of adaptation depends on
the activity during this period..
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Response before adaptation for each channel...
.. Is reduced depending on each channels
adaptation.
The peak of the extrapolated curve .. Is thus
shifted.
Hypothetical channels
Amount of adaptation
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Structure and organization of the cortex
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Pinwheels in the cortex
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Visualizing orientation columns in the cortex
(Using radioactive deoxyglucose)
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Ocular dominance bands over the cortex
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What happens beyond the hypercomplex
cells? Grandmother cells heirarchy prosopagnosi
a face cells hand cells anatomy
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transient cells
magnocellular layers of LGN
parvocellular layers of LGN
sustained cells
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Stimuli used to investigate processing of cells
in the inferotemporal region. The image of the
monkeys hand elicited the largest response.
...from a cell in the Inferotemporal cortex
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A face cell.
...from the Inferotemporal cortex
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damage to the face cell area in the
inferotemporal cortex
causes PROSOPAGNOSIA. A specific inability to
recognize faces.
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As promised .. The following is a question that
will appear on the midterm next week (no, I did
not promise to ANSWER it too.!
GOOD LUCK!
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REVISION
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Keywords for lecture 1
electromagnetic spectrum, (pit viper), mechanical
energy, chemical energy, stages of vision, (i)
eye movements, (ii) focus, (iii) light
regulation, pupil, pin-hole camera, refraction,
focus, cornea, lens, accommodation, myopia,
hyperopia, astigmatism, presbyopia, diving
animals, (i) mask, take out cornea on land and
use powerful lens (ii) flat cornea, (iii)
pin-hole, (iii) brute force solution lens can
go from air-dwelling type through to water
dwelling type (iv) four-eyed fish, (mermaids)
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Keywords for lecture 2
depth of focus, ophthalmoscope, retina, retinal
blood vessels, fovea, optic disk, blind spot,
retina, cells, cell membrane, ions, potassium,
sodium, channels (meaning 1), neurones, resting
potential (-70mV), action potential, synapse,
neurotransmitter, Schwann cells, axon, dendrites,
polarization, depolarization, hyperpolarization,
dark/light adaptation, rods, thresholds,
sensitivity, cones, visual purple, Purkinje
shift, scotopic, photopic, fovea, receptive
fields, bipolar cells, (excitatory and inhibitory
types), retinal ganglion cells, on-centre
off-surround, off-centre on-surround, concentric
organization
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Keywords for lecture 3
retinal ganglion cells, on-centre off-surround,
off-centre on-surround, concentric organization,
spontaneous firing rate, excitation, inhibition,
retinal ganglion cells as edge detectors, Mach
bands, "scalloped illusion", simultaneous
contrast, seeing (or not seeing) gradient (4
retinal ganglion cell demonstrations) information
passing down the optic nerve, optic chiasm,
magnification factor, partial decussation,
thalamus, cortex, brainstem, olfactory
'swelling', visual 'swelling', hearing and
balance 'swelling', lateral geniculate nucleus of
thalamus (perception), Edinger-Westphal nucleus
(pupil), superior colliculus (fast eye
movements), vestibular nucleus (slow eye
movements)
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Keywords for lecture 3 (contd)
lateral geniculate nucleus of thalamus,
magnocellular and parvocellular layers, sustained
and transient cells, cortex (cortices), cerebral
hemispheres, cerebellum, sulcus (sulci), gyrus
(gyri), functional localization over the cortex,
phrenology, primary sensory projection areas,
association cortex, frontal, parietal,
inferotemporal, visual cortex, area 17, Brodmann,
retinotopic map, Hubel and Wiesel, simple cells,
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Keywords for lecture 4

simple cell receptive fields, relation to retinal
ganglion cells, tuned for (i) orientation, (ii)
width-of-bars, (iii) movement, (iv)
direction, binocular complex cells, hypercomplex
cells, grandmother cell hypothesis, orientation
columns, hypercolumns, pinwheels, ocular
dominance bands, radioactive deoxyglucose,
autoradiographs, inferotemporal cortex (ventral
stream), prosopagnosia, parietal cortex (dorsal
stream), tilt after effect, channels (meaning 2),
adaptation (psychophysical technique)
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Left over keywords.
grandmother cell hypothesis, orientation columns,
hypercolumns, pinwheels, ocular dominance bands,
radioactive deoxyglucose, autoradiographs,
inferotemporal cortex (ventral stream),
prosopagnosia, parietal cortex (dorsal stream),
tilt after effect, channels (meaning 2),
adaptation (psychophysical technique)
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There will be 37 multiple choices 1 point each
Total 37 points 100 Counts for 30
or 40 if it is your best.
A question from next weeks exam
14 A synapse is a) another name for a nerve cell
or neurone b) the membrane on which the
photopigment is stored in rods and cones c) the
gap between nerve cells across which they can
communicate d) a cell that wraps itself around
the axon of a neurone e) none of the above