PSYCH 2220 Sensation & Perception I Lecture 4

1. PSYCH 2220 Sensation & Perception I Lecture 4

2. 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)

3. 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,

6. Lateral geniculate nucleus of the THALAMUS

7. Organization of the lateral geniculate of the THALAMUS (1) Parvocellular layers (3- 6) Magnocellular layers (1- 2)

8. 6 5 4 3 2 1 6 5 4 3 2 1 Injection of tracer to left eye

10. CORTEX

12. Magnification factor when looking at the centre, each letter uses the same amount of cortex

13. David Hubel Torsten Wiesel Plotting the receptive field of a simple cell…..

14. 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.

16. SIMPLE CELLS are orientation tuned...

17. Visual cortical cells are orientation tuned Response preferred orientation Orientation

18. Complex cells

20. video about cortical cells

21. Tuning for orientation of bars Tuning for width of bars

24. Activity profile while viewing the test stimulus

25. Activity profile while viewing the adapting stimulus… the amount of adaptation depends on the activity during this period..

26. 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

27. Structure and organization of the cortex

31. Pinwheels in the cortex

32. Visualizing orientation columns in the cortex (Using radioactive deoxyglucose)

33. Ocular dominance bands over the cortex

35. What happens beyond the hypercomplex cells? Grandmother cells heirarchy prosopagnosia face cells; hand cells anatomy

37. transient cells magnocellular layers of LGN parvocellular layers of LGN sustained cells

38. 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

39. A face cell…. ...from the Inferotemporal cortex

40. damage to the face cell area in the inferotemporal cortex… … causes PROSOPAGNOSIA. A specific inability to recognize faces.

43. 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!

44. REVISION

45. 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)

46. 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

47. 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)

48. 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,

49. 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)

50. 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)