Sistem Sensoris Pertemuan 21

1. Matakuliah : L0044/Psikologi Faal Tahun : 2009 Sistem Sensoris Pertemuan 21

2. Sistem Sensoris

3. untuk berhubungan dengan dunia luar kumpulan reseptor yang sensitif terhadap rangsang (reseptor sensorik) → alat indera terdiri dari : a. alat penerima rangsang (reseptor), yaitu alat indera itu sendiri b. saraf penghubung antara reseptor dengan pusat susunan saraf c. pusat saraf (otak), yaitu alat yang bertugas menerjemahkan dan mengelola rangsangan Panca indera mempunyai fungsi tertentu dan peka terhadap rangsang tertentu pula Receptor potential : a slow, graded electrical potential produced by a receptor cell in response to a physical stimulus

4. Two Categories of Receptors • Somatic Senses: touch, pressure, temperature, and pain. Distributed throughout skin and deeper tissues. • Special senses: smell, taste, hearing, equilibrium, vision. (more complex)

5. Receptor Types • Chemoreceptors • respond to changes in chemical concentrations • Pain receptors (Nociceptors) • respond to tissue damage • Thermoreceptors • respond to changes in temperature • Mechanoreceptors • respond to mechanical forces • → proprioceptor, baroreceptor, stretch receptor • Photoreceptors • respond to light

6. Sensations • A feeling that occurs when the brain interprets sensory impulses • All the nerve impulses that travel away from sensory receptors into the CNS are alike. The resulting sensation depends on which region of the brain receives the impulse.

7. Semua impuls saraf dari berbagai reseptor sensorik adalah sama. Sensasi yang dihasilkan tergantung dari daerah korteks serebral mana yang menerima impuls tersebut. • Pada saat yang sama ketika sensasi terbentuk, serebral korteks menerjemahkan darimana reeptor yang terstimulasi → seseorang dapat menunjukkan area stimulasi →PROJECTION • Adaptasi sensorik Bila reseptor sensorik terus menerus terstimulasi, membran reseptor akan menjadi kurang responsif terhadap stimulus contoh : seseorang yang berada di pasar ikan

8. SPECIAL SENSES 1. Mata, merupakan indera penglihatan (organ visual) sensitif terhadap rangsangan cahaya, menerima bayangan serta kesan-kesan untuk ditafsirkan 2. Telinga, merupakan indera pendengaran (organ auditorik), di sini kesan atas suara atau bunyi diterima dan ditafsirkan 3. Hidung, merupakan indera pembau / penciuman (organ olfaktorius), sangat peka dan kepekaannya mudah hilang 4. Lidah, merupakan indera pengecapan, yang sangat peka (sensitif) terhadap rasa seperti pahit, manis, asam, dan asin 5. Kulit, merupakan indera peraba, sangat peka terhadap tekanan, suhu, sentuhan, dan rabaan

9. Hole, Human Anatomy & Physiology, 10th ed

10. Penglihatan

11. Apakah informasi yang kita terima dari dunia luar adalah suatu realitas ? 1. Reseptor sensorik manusia hanya dapat mendeteksi jumlah yang terbatas dari bentuk energi yang ada contoh : gelombang radio, gelombang magnet tidak dapat dideteksi oleh reseptor sensorik manusia 2. Informasi yang disalurkan ke otak manusia tidak melalui alat perekam canggih yang peka. Selama proses prekortikal dari input sensorik, beberapa stimuli ditingkatkan sedangkan yang lain dapat ditekan atau diabaikan 3. Serebral korteks selanjutnya akan memanipulasi data yang didapatkan dari reseptor sensorik, dibandingkan dengan informasi lain seperti ingatan dari pengalaman yang lalu

12. Sherwood, Human Physiology From Cells to Systems, 6th ed

13. Kanizsa’s Triangle

14. “Peripheral drift” by Akiyoshi Kitaoka Taken from Nationalgeographic.com

15. Which Line is Longer? They are both the same. Explanation • This is one of the most studied illusions, and was created by a German psychiatrist Franz Müller-Lyer in 1889. It it not well understood why this illusion works, but we think it is related to the fact that the first object is simply larger, and the second object is "pointed." • http://www.optical-illusions.biowaves.com/Perspective/MullerLyerLineLength.cfm

16. Are the Red Lines Parallel? http://www.optical-illusions.biowaves.com/Perspective/ParallelLines.cfm

17. Spinning Effect Optical Illusion • Move toward and away from the screen while staying focused on the red dot. • Notice that the outer rings seem to rotate or spin when you move toward or away from the screen. Explanation • The eye interpretes visual cues to assist in day to day living. In this case, the visual cues mislead one to percieve motion. • http://www.optical-illusions.biowaves.com/Misc/SpinningEffect.cfm

18. Disappearing Haze • Stare at the Red Dot. • Notice that the haze disappears after 20 to 30 seconds. Explanation • The retina gradually changes senstivity to adapt to the existing light conditions. This is what allows the eyes to work with such incredibly diverse light conditions, from bright sunlight to faint moonlight. You can learn more about this on our pages about eyesight. • http://www.optical-illusions.biowaves.com/Color/DisappearingHaze.cfm.

19. Do you See Gray? • This picture is only made with black and white. • You can see that the above picture all black and white by covering either side of a white row with paper. Explanation • The eye, which responds to an amazing wide variety of light sources, from moon light to direct sunlight, tries to adjust to the present light levels. Here, the contrast is so strong and irregular, the white ends up looking gray. • You can learn more about color perception here. • http://www.optical-illusions.biowaves.com/Color/DisappearingHaze.cfm.

20. The Stacked Blocks Optical Illusion • Are the lines straight and level? • The lines are all exactly parallel. Explanation • The eye interpretes visual cues to assist in day to day living. In this case, visual cues mislead they eye to perceive an increased distance, therefore a narrowing where the blocks recede. http://www.optical-illusions.biowaves.com/Distortions/StackedBlocks.cfm

21. Are the Boxes the Same Size? Explanation • Yes, they really are exactly the same size. Hard to believe, isn't it. The artist is taking advantage of a very powerful three dimensional technique where all of the lines meet at one point off the edge of the canvas, thus making the mind see the picture as a 3-D model of reality, rather than just lines on a screen.. The eye then adjusts for the 3-D effect, which results in the farthest block looking much larger. http://www.optical-illusions.biowaves.com/3D/PerspectiveBoxes.cfm

22. IS THIS SPIRAL? LOOK AGAIN, THEY ARE ALL SEPERATE CIRCLES http://www.indianchild.com/is_this_spiral.htm

23. Seeing is believing

24. MATA • analog dengan kamera • terletak di dalam rongga mata (Orbital Cavity) • 70% dari reseptor sensorik terletak pada mata • digerakkan oleh otot mata otot lurus : m. rektus okuli superior, inferior, medial, dan lateral otot serong : m. obliquus okuli superior dan inferior • Bagian : kornea, Iris, pupil, lensa, retina (sel batang dan kerucut) sclera, kamera okuli anterior dan posterior, humor aqueous, humor vitreous • lateral terhadap bintik buta (tempat keluarnya pembuluh darah dan saraf), terdapat daerah lonjong disebut makula lutea, dengan cekungan kecil di pusatnya disebut fovea sentralis (hanya mengandung kerucut)

25. Neil R. Carlson, Physiology of Behaviour, 9th ed Mata manusia dapat menangkap radiasi elektromagnet dengan panjang gelombang 380 - 760 nm Kecepatan Cahaya : 300.000 km/detik Persepsi terhadap Warna ditentukan oleh : - Hue (ditentukan oleh panjang gelombang) - Brightness (intensitas) - Saturation (purity)

26. Neil R. Carlson, Physiology of Behaviour, 9th ed

27. Hole, Human Anatomy & Physiology, 10th ed

28. Cornea • Bulges forward • Transparent window of the eye (contains few cells, no blood vessels, cells and collagenous fibers form unusually regular patterns) • Helps focus entering light rays. • Continuous with the sclera (white portion of the eye)

29. Sclera • White portion of the eye • Posterior 5/6th of the outer tunic • Opaque due to many large, disorganized collagenous and elastic fibers. • Protects the eye and is an attachment for the extrinsic muscles

30. Lens • Lies directly behind the iris and pupil • Composed of differentiated epithelial cells called lens fibers. Lens Capsule • Surrounds the lens • Clear, membrane-like structure composed largely of intercellular material • Elastic nature keeps it under constant tension. Can assume a globular shape.

31. Human Eye – cross Hole, Human Anatomy & Physiology, 10th ed

32. Neil R. Carlson, Physiology of Behaviour, 9th ed

33. Hole, Human Anatomy & Physiology, 10th ed

34. Hole, Human Anatomy & Physiology, 10th ed

35. Hole, Human Anatomy & Physiology, 10th ed

36. Iris • The colored part of the eye • Thin diaphragm composed mostly of connective tissue and smooth muscle fibers • Pupil – central opening of the iris • Regulates the amount of light entering the eye during: • Close vision and bright light – pupils constrict • Distant vision and dim light – pupils dilate • Changes in emotional state – pupils dilate when the subject matter is appealing or requires problem-solving skills • Divides the space (anterior cavity) into the anterior chamber (between the cornea and the iris) and posterior chamber (between iris and vitreous body containing the lens)

37. Hole, Human Anatomy & Physiology, 10th ed Dim light stimulates the radial muscles of the iris to contract, and the pupil dilates. Bright light stimulates the circular muscles of the iris to contract, and the pupil constricts.

38. Suspensory ligaments attached to margin of lens capsule and the ciliary muscles. Changing tension changes the shape of the capsule and lens for focusing. • Accommodation: the ability of the lens to adjust shape to facilitate focusing. Close objects= lens thickens; distant objects= thinner, less convex

39. Hole, Human Anatomy & Physiology, 10th ed

40. Hole, Human Anatomy & Physiology, 10th ed

41. Neil R. Carlson, Physiology of Behaviour, 9th ed

42. Hole, Human Anatomy & Physiology, 10th ed

43. Summary of Cranial Nerves and Muscle Actions • Names, actions, and cranial nerve innervation of the extrinsic eye muscles Sherwood, Human Physiology From Cells to Systems, 5th ed

44. Hole, Human Anatomy & Physiology, 10th ed

45. Pergerakan Mata : • Vergence movement : the cooperativew movement of the eyes, which ensures that the image of an object falls on identical portions of both retinas • Saccadic movement : the rapid, jerky movement of the eyes used in scanning a visual scene • Pursuit movement : the movement that the eyes make to maintain an image of a moving object on the fovea Accomodation : changes in the thickness of the lens of the eye, accomplished by the ciliary muscles, that focus images of near or distant objects on the retina

46. Aqueous Humor • Watery fluid secreted by the epithelium on the inner surface of the ciliary body into posterior chamber.

47. Sherwood, Human Physiology From Cells to Systems, 5th ed

48. Aparatus Lakrimalis Consists of the lacrimal gland and associated ducts • air mata dihasilkan oleh kelenjar lakrimalis superior dan inferior. Melalui duktus ekskretorius lakrimalis masuk ke dalam sakus konjungtiva. Melalui bagian depan bola mata terus ke sudut tengah bola mata ke dalam kanalis lakrimalis mengalir ke duktus nasolakrimalis terus ke meatus nasalis inferior. • Tears • Contain mucus, antibodies, and lysozyme • cleanse and protect the eye surface as it moistens and lubricates it • Enter the eye via superolateral excretory ducts • Exit the eye medially via the lacrimal punctum • Drain into the nasolacrimal duct

49. Hole, Human Anatomy & Physiology, 10th ed

50. Hole, Human Anatomy & Physiology, 10th ed