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PSYCH 2220 Sensation & Perception I Lecture 4. Keywords for lecture 3.

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PSYCH 2220 Sensation & Perception I Lecture 4

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PSYCH 2220

Sensation & Perception I

Lecture 4


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)


Keywords for lecture 3 (cont’d)

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,


Lateral geniculate nucleus of the THALAMUS


Organization of the lateral geniculate

of the THALAMUS (1)

Parvocellular

layers (3- 6)

Magnocellular

layers (1- 2)


6

5

4

3

2

1

6

5

4

3

2

1

Injection of

tracer to left eye


CORTEX


Magnification factor

when looking at the centre, each letter uses

the same amount of cortex


David Hubel

Torsten Wiesel

Plotting the receptive field

of a simple cell…..


  • 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.


SIMPLE CELLS

are orientation tuned...


Visual cortical cells are orientation tuned

Response

preferred

orientation

Orientation


Complex cells


video about cortical cells


Tuning for orientation of bars

Tuning for width of bars


Activity profile while viewing the test stimulus


Activity profile while viewing the adapting stimulus…

the amount of adaptation depends on the activity

during this period..


Response before adaptation for each channel...

.. Is reduced depending on each channel’s adaptation.

The peak of the extrapolated curve…

.. Is thus shifted.

Hypothetical

channels

Amount of

adaptation


Structure and organization of the cortex


Pinwheels in the cortex


Visualizing orientation columns in the cortex

(Using radioactive deoxyglucose)


Ocular dominance bands over the cortex


What happens beyond the hypercomplex cells?

Grandmother cells

heirarchy

prosopagnosia

face cells; hand cells

anatomy


transient cells

magnocellular layers of LGN

parvocellular layers of LGN

sustained cells


Stimuli used to investigate processing of

cells in the inferotemporal region. The image of the monkey’s hand elicited the largest response….

...from a cell in the Inferotemporal cortex


A face cell….

...from the Inferotemporal cortex


damage to the face cell area in the inferotemporal cortex…

… causes PROSOPAGNOSIA.

A specific inability to recognize faces.


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!


REVISION


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)


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


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)


Keywords for lecture 3 (cont’d)

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,


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)


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)


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 week’s 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


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