BEYİN BİLİM VE SİHİR. Volkan Özgüz

Transkript

1 BEYİN BİLİM VE SİHİR Volkan Özgüz

2 Beyin Bilim ve Sihir : içerik Beyinin çalışma prensipleri Duyu organlarımızın temel özellikleri Beyin hakkında en fazla bilgi sahibi olanlar sihirbazlar mı? Beynin bilimi ile sihirin bilimi aynı mı? Algılamanın bilimsel ve nörolojik temelleri Beynin nörolojik yapısı gerçekten bilgisayara benzer mi? Son yıllarda hızla gelişen bilimsel bulgular beyin hakkında bilinenleri nasıl değiştiriyor?

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4 Beynimiz hakkında ne biliyoruz? Sayısızaraştırmacı, yayın, kitap ama Beyin bir kara kutu Gözlemlerdaha çokdışardan kutudışında yapılanölçmeler Kara kutu içinde yapılan yeni gözlemlerbeyin hakkındabilgimizi yeniliyor: nörobiyoloji

5 Bildiğimizi Görüyoruz!

6 Ne Gördüğümüzü Bilmiyoruz!

7 Gördüklerimiz Biz Şaşırtıyor! Penney video (1 min)

8 Beyin hakkında bildiklerimiz ve bilmediklerimiz 100,000 lerce araştırıcı, miyonlarca sayfa belge Beyin bir ampul kadar enerji harcıyor: watt Enerjiyi en az şekilde tüketmek için ilk fırsatta sonuca ulaşma Yaşamak için sonuca hızlıca ulaşma Durumdan yararlanarak sonuca ulaşma Belirsizlik kaçınma ve ihmal etme ve şüpheli durumları bastırma Hızlı ve yavaş süreçler Hızlı : sonuca ulaşmak Yavaş: düşünme, analitik işler, bilgi işlem, hesap vb

9 Beynimizdeki işlevler

10 Bilinç ve bilinçsizlik? Bilinç, Bilinç altı ve üstü (?) Düşünüyorum o halde varım! Bir ben vardır bende, benden içeri Yaşayan zombiler

11 Beyin Bilim Sihir Beyin hakkında en fazla bilgi sahibi olanlar sihirbazlar mı acaba? Beynin bilimi ile sihirin bilimi aynı mı? Keith Barry Video (5/11 min)

12 The Economist

13 Omurgalılar (örnek: insanlar, birçok memeli hayvanlar) Omurgalıların beyni, sonradan omuriliğe dönüşecek olan arkadaki bir nöral tübün öndeki kısmından gelişir Omurgalılarda beyin kafatası kemikleri tarafından korunmaktadır

14 Beynin Anatomisi Korteks insan beyninin kütlesinin yaklaşık %76 sını oluşturur Neokorteks beyin hemisferlerinin en dış tabakasını oluşturur Neokorteks canlılarınçevredeki olaylarınfarkına varmasını sağlar (algı ve varlık) Serebral korteksin kıvrım sayısı, canlının evrim basamağındaki yeri belirler Balık, sürüngen gibi ilkel omurgalılar beyni altı katmandan daha azvekıvrımaz

15 İnsan Beyninin Anatomisi Limbik system motor ve duyumu birleştirir Limbik sistemin kortikalparçaları: arkikorteks paleokorteks Limbik sistemin diğer parçaları : hipotalamus, hippokampus amigdala

16 İnsan Beyninin Anatomisi Neokorteks, herbiri değişik fonksiyonlara sahip temporal, frontal, paryetal ve oksipital loblardan oluşur Oksipital lob, primer görme korteksini barındırır Primer işitme merkezi temporal lobtadır Dil ile ilgili işlemler ventrolateral frontal korteksteki Broca alanında Sosyal ve duygusal işlevlerse orbitofrontal kortekste

17 Sol hemisfer görevleri Sayısal hesaplama (tam olarak hesaplama, sayısal karşılaştırma, tahmin) Doğrudan gerçek alımı Dil: dilbilgisi / kelime Sağ hemisfer görevleri Hesaplama (yaklaşıkhesap, karşılaştırma, tahmin) Dil: tonlama / vurgulama, prozodi, pragmatik, bağlamsal

18 Hipotalamus Vücutun gereksinimlerini kontrol eden çekirdek Diencepheleon in between brain Beynin 1/300 ü Ancak en basit sorunu temel fiziksel ve zihinsel sorunlar oluşturur

19 Bademe benzeyen ve medial temporal lobların derinliklerinde ve sadece üst düzet omurgalılarda olan bir yapı En önemli görevi bellek ve duygusal reaksiyonları (örnek: korku) control etmek Amigdala libik sitemin bir parçası olarak Kabul edilir Amigdala

20 İnsan Beyninin Anatomisi Neokorteks sinir hücresi gövdelerinden ve myelinsiz sinir liflerinden oluşur (gri madde) Neokorteks myelinli sinir liflerinden oluşan beyaz maddeyi kuşatır Kıvrımveoyuklarla hacim artmadan yüzey önemli ölçüde genişler Nöronlar ve sinapslar

21 İnsan Beyninin Anatomisi : Nöron Nöronlar: çap 4 mikron (0.004 mm) mikron (0.1 mm) Akson: 10 mikron mikron uzunluk, 0.3 mikron çap, 4000 m/mm 3 Dendrit: 0.9 mikron çap, 400 m/mm 3

22 Nöronlar ve Neokorteks Neokorteks I. en dışta, VI. en içte olmak üzere 6 tabakadan meydana gelir İnsan bilinci modern neokorteksin genişlemiş kapasitesi kadar beyin sapının gelişmiş yapıları üzerine de kurulmuştur Duyu algılaması, motor emirlerin oluşumu, uzaysal muhakeme, bilinçli düşünme ve dil gibi yüksek fonksiyonların yürütülmesinde görev alır

23 Nöronlar ve Neokorteks Neokorteks temelde iki tip nörondan oluşur: uyarıcı özellikteki piramidal nöronlar (%80) ve inhibe edici aranöronlar (%20) Neokorteks 6 tabakadan oluşsa da istisnai sahalar da var Motor kortekste VI. katman yok II. ve III. tabakalarınaksonları neokorteksin diğer bölgelerine uzanır derindeki V. ve VI. tabaka aksonları talamus, beyin sapı ve medulla gibi korteks dışı yapılarla bağlantı kurar IV. tabaka nöronları çoğu talamustan olmak üzere dış yapılardan bilgi alırken kısa bağlantılarla korteksin diğer kısımlarına iletiler gönderir

24 Different Neuron Types Sensory neurons or Bipolar neurons carry messages from the body's sense receptors (eyes, ears, etc.) to CNS. Sensory neuron account for 0.9% of all neurons. (Examples are retinal cells, olfactory epithelium cells) Motoneurons or Multipolar neurons carry signals from the CNS to the muscles and glands. Motoneurons account for 9% of all neurons. (Examples are spinal motor neurons, pyramidal neurons, Purkinje cells.) Interneurons or Pseudopolare cells form the neural wiring within the CNS. These have two axons (instead of an axon and a dendrite). One axon communicates with the spinal cord; one with either the skin or muscle (Examples are dorsal root ganglia cells) GLIA cells: Glial cells, sometimes called neuroglia or simply glia "glue"; are cells that maintain homeostasis, form myelin, and provide support and protection for neurons in the brain and peripheral nervous system New functions are revealed recently about glia cells: indirect contributions to the cognitive processes

25 Mirror Neurons A mirror neuron fires both when someone acts and when someone observes the same action performed by another The neuron "mirrors" the behavior of the other, as though the observer were itself acting Found in the premotor cortex, the supplementary motor area, the primary somatosensory cortex and the inferior parietal cortex Provides the physiological mechanism for the perception/action coupling may be important for understanding the actions of other, and for learning new skills by imitation Mirror neurons are the neural basis of the human capacity for emotions such as empathy No widely accepted neural or computational models have been put forward to describe how mirror neuron activity supports cognitive functions such as imitation

26 Nöronlar arası Haberleşme Nöronlar birbirleri ile elektrokimyasal sinyallarle haberleşirler Aksonlar nöronlardan dışarı bilgi aktarır Dendritler nöronlara doğru bilgi taşır Aksonlarla dendritlerilerle bir ince aralıkta birleşirler : sinaps Sinapstan bilgi taşımak için akson nörotransmiter denilen kimyasallar üretir Sinapstan geçen kimyasallar diğer nöronunda nörotransmitter üretmesini tetikler: herşeyin temeli Sinaps işlemleri zaman ve yer anlamında kısa ve uzun vadeli olarak değişirler (Spike-timing-Dependent- Plasticity) herşeyin temeli

27 Değişik nöronlar değişik nörotransmiterler üretir: 50 den fazla Dopamin: fiziksel etkinlikler yokluğu Parkinson hastalığının temeli fazlalığı şizofren Serotonin: uyku, kan basıncı, iştah vb fiziksel-duygusal yapıyı kontrol eder - anksiyete Noradrelanine: zevk duygusu Ensafalin ve endorfin: nefes alma, stres, acı, sakinlik, bağımlılık Asetilkolin (ACh) : bilgi, öğrenme, dikkat, bellek - Alzheimers Glutamat: en temel nöral iletişim aracı: öğrenme ve bellek

28 Nöronlar arası Haberleşmenin Kodları How is information encoded in populations of neurons? 1. Quantities are encoded as rate codes in ensembles of neurons (e.g, Shadlen and Newsome, 1998). 2. Quantities are encoded as precise temporal patterns of spiking across a population of cells (e.g, Abeles, 1991) Operating frequencies of processes and spikes are about Hz

29 Neural Recordings

30 Beyin Görüntüleme Teknikleri 30

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34 Mouse Brain 2 min

35 Neuronal activity 3/5 min

36 Eye and Vision The rods, some 120 million are more sensitive than the cones but not to color The 6 to 7 million cones provide the eye's color sensitivity: three different types of cones for color reception, red, green, blue (RGB) Cones are concentrated in the central yellow spot known as the macula Fovea,0.3 mm diameter rod-free area with very thin, densely packed cones, a special section of macula with highest resolution Vision system has poor resolution except at the center : macula (macular degeneration)

37 FOVEA

38 Eye

39 Eye

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41 Eye and Vision Visual processing begins when photons entering the eye strike one or more of the 125 million light sensitive nerve cells in the retina. This first layer of cells, which are known as rods and cones, converts the information into electrical signals and sends them to an intermediate layer, which in turn relays signals to the 20 or so distinct types of retinal ganglion cells.

42 Eye and Vision Optic nerve contains all the fibers that send visual information to your brain Each optic nerve is made up of millions of neural wires Each wire is called an axon representing one pixel in the eye Eye is equivalent to a megapixel camera

43 Visual System Processing The visual system processes information at many levels of sophistication At the retina, there is low level vision, including light adaptation and the center surround receptive fields of ganglion cells At the other extreme is high level vision,which includes cognitive processes that incorporate knowledge about objects, materials, and scenes. In between there is mid level vision Mid level vision is simply an ill defined region between low and high The representations and the processing in the middle stages are commonly thought to involve surfaces, contours, grouping, and so on Lightness perception seems to involve all three levels of processing Filling in capability

44 Vision Processing Center surround antagonism refers to antagonistic interactions between center and surround regions of the receptive fields of photoreceptor cells in the retina Center surround antagonism enables edge detection and contrast enhancement within the visual cortex Center surround couples with winner takes all WTA where largest neuronal activity suppresses other activities

45 Dominant Eye Baskın Göz

46 Visual Field

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49 Visual Field

50 Kendin Dene Oyun kağıdı destesinden sadece resimli kartları tut Odada uzak bir yere odaklan Desteden bakmadan bir kart seç (resim tarafı sana dönük olsun) Elinde görme sınırında (yani kolunun açılabileceği en sol veya sağda tut) Yavaşca kolunu öne doğru döndürmeye başla Kartın hangi kart olduğunu ne zaman görüyorsun?

51 Visual Field and Eye Movement Saccades and fixation Saccades are for searching information Fixation is when eyes are motionless Smooth pursuit is for tracking movement Saccades are needed because only 1/10 th of the retina has some kind of resolution and surrounding visual field is poor quality When your gaze stops on an object and does not move acitiviy in your visual neurons is suppressed Overt attention and over misdirection

52 Visual Field without Saccades

53 Top Down vs Bottom Up Feed Forward vs Feed Back

54 Vision Fovea Saccading Attention Surprising theory of attention Itti et al., IEEE Trans. PAMI 1998; Vision Res. 2000; Nature Reviews Neurosci. 2001; IEEE Trans. IP 2004

55 Feed Forward vs Feed Back Fast vs Slow Paths Fast Feed forward triggers attention Feed back provides recognition

56 Feed Forward vs Feed Back: Fast vs Slow Paths Fast Feed forward triggers attention Feed back provides recognition

57 Surprising Theory of Attention Attention need strong input from Prefronatal Cortex Attention results from the activation of inhibitory neurons which in trun suppress neurons in the surrounding visual (or auditory) neurons that could cause distractions (center surround) Babies and children don t supress surrounding distracters as well as adults do

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59 Vision and Attention

60 Finding important information Detecting spatial outliers Saliency Salient locations stand out from their neighbors in at least one visual attribute (e.g., color, motion) E.g., Treisman & Gelade, 1980; Koch & Ullman, 1985; Tsotsos et al., 1995; Li, 1998; Itti, Koch & Niebur, 1998

61 Finding important information In principle, very complex task: Need to recognize all objects in scene? Then match recognition results against memory traces? Finally evaluate set of recognized objects against behavioral goals? In practice, survival depends on ability to quickly locate and identify important information Need to develop simple heuristics or approximations

62 White snow paradox TV news, sports, music, action movies, etc 0.3 MByte/s (640x480, MPEG4, avg. 46,000 frames) Greyscale snow 5.0 MByte/s

63 Vision Processing

64 Vision Processing Grand Mother Neurons?

65 Procedural memory: muscle memory Memories Pyhsical skils: skiing, riding bicycle, shuffling a deck of cards Declarative memory: deals with facts Semantic memory: encodes meaning, definitons and concepts; facts that are not routed in time Episodic or autobiographical memory: experiences from unique past Short-term memory (or "primary" or "active memory") is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory (when rehearsal or active maintenance is prevented) is believed to be in the order of seconds A commonly cited capacity is 7 ± 2 elements. Long-term memory indefinitely stores unlimited amount of information Short-term memory different from working memory: structures and processes used for temporarily storing and manipulating information Memories are encoded in the plasticity of synapses

66 Memories Long-term memory (LTM) is memory in which associations among items are stored LTM differs structurally and functionally from other memory Information can remain in intermediateterm memory for 5 to 8 hours, and in longterm memory indefinitely LTM is an important aspect of cognition LTM can be divided into three processes: encoding, storage, and retrieval Encoding of LTM occurs in the medial temporal lobe, and damage to the medial temporal lobe is known to cause anterograde amnesia

67 Where are memories in our Brain? LTM are sent down the hippocampus from cortex where they are registered as neural patterns similar to the cortex Hippocampus is connected to many parts of the brain: multiple inputs and representations can be globalized Sound of music, taste of the icecream, the smell of the sea < vacation memories (episodes) During sleep «episodes» are recalled replayed (often involuntary ) and reconsolidated > regeneration During recall, memories are sent back to the cortex

68 Famous Memories In Search of Lost Time (French: À la recherche du temps perdu) or Remembrance of Things Past is a novel in seven volumes by Marcel Proust ( ). His most prominent work, it is known both for its length and its theme of involuntary memory, the most famous example being the "episode of the madeleine."

69 Where are our dreams?

70 Memory Problems in the Brain

71 Language Verbalization Language is a system of sounded signs (symbols) Sounds often mean something by themselves form meaning in relation to other signs An important characteristic of human languages in contrast to birdcalls and traffic signs is their productivity A productive language can form an unlimited variety of sentences with different meaning from a relatively smaller sets of words Encoding efficiency for energy efficient communication Verbalization (use of language to reason) is seen as a measure of true intelligence: Turing Test

72 Beynin Çalışma Modeli

73 İnsan Beyninin İşlevleri

74 İnsan Beyninin İşlevleri

75 Lennie, The cost of Cortical Computation, Current Biology, Vol. 13, , March 18, 2003,

76 Beyin ve Enerji Adenosine Triphosphate (ATP) : the human body, contains about 250 grams (8.8 oz) of ATP We recycle about the body weight equivalent in ATP each day Beyin toplamda 60 W kadar bir güç tüketir Bu gücün yaklaşık %40 24 W durağan durumda (resting state harcanır Enerji glukoz dönüşümleri ile ATP tarafından sağlanır/taşınır Lennie, The cost of Cortical Computation, Current Biology, Vol. 13, , March 18, 2003,

77 Beyin Ve Enerji Spike based communication is costly : 100 times more to generate 10 spikes than resting potential Metabolic energy consumption limits the availability of the cortex at 10% Limits the number of the tasks that can be undertaken concurrently Lennie, The cost of Cortical Computation, Current Biology, Vol. 13, , March 18, 2003,

78 Beyin hakkında bildiklerimiz ve bilmediklerimiz

79 Nöronlardan Beliren (Emergent) Özelliklere Milyar Nöron! Her nöron yaklaşık 1000 diğer nörona bağlı Nöronlar yavaş (5 200 Hz) çalışıyorlar Birçok geri ve ileri bildirim çevrimleri var Güç tüketimi W üstüne çıkmıyor Enerji korunumu için hızlı sonuca gitme Yaşamak için sonuca hızlıca gitme Bağlam (context) den faydalanarak hızlıca sonuca gitme Belirsizlik, ikilem ve şüpheden kaçınma Yavaş ve hızlı süreçler Analitik ve hesaplamalı süreçler yavaş Algıdan tanıya 150 ms civarinda ulaşım Süreli öğrenim Bildiğimizi algılama

80 Beyin Bilim Sihir Beyin hakkında en fazla bilgi sahibi olanlar sihirbazlar mı acaba? Beynin bilimi ile sihirin bilimi aynı mı? Keith Barry video

81 Renklerin algılanmasında Hayır mı? iyi misin? A ve B nin renkleri aynı mıdır?

82 Beyin, kareleri, olacağı şekilde algılayabilmek için çaba sarfetmektedir. Yani, biri karanlık ve diğeri beyaz Ayni renkte olmaları farketmiyor Yanyana olan kareler, zıt renkte olmaları lazım Center surround winner take all Bu bize daha iyi bir optik görüş sağlıyor Bu şekilde, etrafımızda daha çok detayın farkına varıyoruz Renkler arasında da daha fazla kontrast Çevremizdeki dünyanın bize ilettiği değil, Bizim algıladığımızı görüyoruz

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84 Beyin, birbirini takip eden parçalarındönme hareketine sahip olması gerektiğini düşünüyor, öyle öğrenmiş

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86 Beyin, doğru yönde gördüğü eski resimleri görmek istemekte

87 Ayrıntılar mı önemli büyük resim mi?

88 Üç boyutlu algı 1 min

89 Visual System Processing The amount of light coming to the eye from an object on the amount of light striking the surface, and on the proportion of light that is reflected If a visual system only made a single measurement of luminance, acting as a photometer, then there would be no way to distinguish a white surface in dim light from a black surface in bright light Yet humans can usually do so, and this skill is known as lightness constancy

90 Visual System Processing Simultaneous contrast effect, which demonstrates a spatial interaction in lightness perception The two smaller squares are the same shade of gray. Illusions like these are sometimes viewed as quirky failures of perception, but they help reveal the inner workings of asystem that functions remarkably well.

91 Visual System Processing The receptive field of an idealized center surround cell The cell exhibits lateral inhibition: light in the center is excitatory while light in the surround is inhibitory This cell performs a local comparison between a given luminance and the neighboring luminances, and thus offers machinery that can help explain the simultaneous contrast (SC) illusion.

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93 Muller Lyer Illusion

94 Muller Lyer Illusion this illusion occurs because of a misapplication of size constancy scaling. In most cases, size constancy allows us to perceive objects in a stable way by taking distance into account. In the three dimensional world, this principle allows us to perceive a tall person as tall whether they are standing next to us or off in the distance. When we apply this same principle to two dimensional objects, errors can result. Müller Lyer illusion may occur because of conflicting cues Our ability to perceive the length of the lines depends upon the actual length of the line itself and the overall length of the figure. Since the total length of one figure is longer than the length of the lines themselves, it causes the line with the outward facing fins to be seen as longer. the illusion demonstrates how the brain reflexively judges information about length and size before anything else.

95 Kanisza Triangle

96 Penrose Triangle

97 Escher Illusions

98 Escher Illusions

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101 Waterfall Gaze İllusion A visual illusion of apparent movement created by gazing for a period of time at a fixed point in a waterfall and then looking at a stationary object, which appears to move upwards. The illusion was first discussed in print by the Greek philosopher Aristotle ( bc) in the Parva Naturalia in the essay On Dreams, although Aristotle did not mention waterfalls: When people turn away from looking at objects in motion, for example rivers, and especially those that flow very rapidly, things really at rest are then seen as moving Also called the waterfall effect or motion aftereffect

102 Waterfall Gaze Illusion 1min

103 Beyin Bilim Sihir Beyin hakkında en fazla bilgi sahibi olanlar sihirbazlar mı acaba? Beynin bilimi ile sihirin bilimi aynı mı?

104 Visual Field and Eye Movement Saccades and fixation Saccades are for searching information Fixation is when eyes are motionless Smooth pursuit is for tracking movement Saccades are needed because only 1/10 th of the retina has some kind of resolution and surrounding visual field is poor quality When your gaze stops on an object and does not move acitiviy in your visual neurons is suppressed Overt attention and over misdirection

105 Surprising Theory of Attention Attention mechanisms of children are diffferent Children can pick up many extraneous stuff Children are harder to fool: because they are not sophisticated enough to be fooled! Children believe in magic When does chid s mind reach a level that allows to be amazed by a magic trick? What do babies know? Are we «statistical learning machines»?

106 Saccades and Smooth pursuit

107 Frames of Attention Frames and attention Exogenous attention capture or passive misdirection Attention is drawn to moving, bright, flashy objects Fluttering bird, flashing lights Examples turning the pages of a book Mind s eye mind s ear > mirror neuron Mimicking others actions Mind body

108 Misdirection

109 Control Of Attentional Focus One area of neuroscience research in which magicians might have stolen the show is the dynamic control of attentional focus Pickpockets move their hands in a curvilinear motion to misdirect the attention of the mark along the curvilinear trajectory, whereas they move their hands in a fast linear fashion to invoke fast attentional shifts from one spatial location to another, which serves to reduce the strength of the attentional focus. One possibility is that these effects are due to differential engagement of the smooth pursuit and saccadic oculomotor systems. The curvilinear motion could draw the mark s oculomotor system into a long pursuit of the pickpocket s wandering hand; the foveal centre of vision would then follow the length of the trajectory, presumably dragging the attentional spotlight along with it. The fast straight motion could invoke a saccadic eye movement, and the suppression of visual perception that is known to occur during saccades might result in reduced attention.

110 Control Of Attentional Focus A second possibility is that, rather than the oculomotor system being differentially affected by the two types of motion, curvilinear target motions might be perceptually more salient than linear target motions, irrespective of eye movements. Curves and the corners of object surfaces are perceptually more salient and generate stronger neural activity than straight edges, possibly owing to the fact that they are less redundant and predictable (and therefore more novel and informative. This decreased redundancy argument might also apply to nonpredictable object motion trajectories. If this is the case, curvilinear motion trajectories should be more salient (and consequently engage stronger attention) than straight trajectories.

111 Mind s body Stealing watch 3/11 min

112 Mind s body Personal space, peripersonal space Immediate surronding of your body is part of your body Tickle without touching!! Pickpockets uses this feature Following circular motions is more important than straight lines

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114 Brain Map

115 Bending the spoon 3 min

116 Distraction Diversion Ratcheting Amodal completion Object occluded by another object appears as whole

117 Count the passes 1min

118 Multitasking The brain can only attend to few things at a time! Cannot give full attention to both of the visual tasks and auditory task Striatum (brain region involved in learning new things) is used when distracted Hippocampus (brain region involved in storing and recalling information) is used when not distracted

119 İsim: Boubba? Kiki?

120 Multi Sensor Integration Brain integrates informaiton from multiple sensory inputs: sight, hearing, touch, smell, taste balance, self motion and feelings Hear loud noise and see bright light you are thinking that they are related P T K > puff of air Bouba and kiki effect People may see A as red, 7 as yellow, or hear Chopin preludes as sad McGurk effect video Video rubberhand and out of body synthesia

121 Pronounce colors 1 min

122 BINDING problem Superior colliculus is densely packed by multisensory neurons Are these neurons widely connected? Not possible that all are connected How do they fire in concert? Objects have different color, shape sound and smell How does your brain figure out which features belongs to the same object How are unified concious experiences bound in your brain? Binding problem? Feature integration theory: act of selective attention? Science is looking for answers Magicians uses it!!

123 Mind reading

124 Mind reading

125 Mind Reading and Attention

126 Memory and Attention Door study 2 min

127 Belleğimize ne kadar Güvenmeliyiz Bir süreden beri İspanya dakisiyasigelişmelerden rahatsız olan çevreler 23 Şubat 1981 de akşam saat 18:30 da Yarbay Antonio Tejero kumandasında silahlı 200 adet jandarma eriyle beraber İspanyol Parlamentosunu basar ve milletvekillerini 18 saat rehin tutarlar Bu sırada meclisteki görüşmeleri canlı yayınlayan televizyon kameraları darbeyi yaklaşıkyarım saat kaydedecek ve bu tarihi olayla ilgili çok önemli görsel bir belge elde edilecektir Birçok seyirci yıllar sonra olayı TV de canlı gördüklerini, olayları en ince ayrıntılarına hatırladıklarını anlatırlar İlginç olan olay aslında canlı değil, bir gün sonra teypten yayınlanmıştır. Yani olayları doğrudan görmemişlerdir.

128 Coin toss That wasn t You throw a coin in the air and the coin disappears Implied or Inferred Motion Illusion The magician throws few times before (priming) Then he makes like he throws but keeps the ball At the same time he closes his left hand Visual region of the brain called Lateral Intraparietal (LIP) tracks the movement of objects in space and time

129 Coin toss That wasn t Visual region of the brain called Lateral Intraparietal (LIP) tracks the movement of objects in space and time The magician s right hands stops but the brain assumes the movement goes on The movement selective neurons of two other visual area called MT sense the motion of left hand closing Assumes that left hand catches the ball Think of «fakes» in sports «or dog following a stick that wasn t thrown

130 Two Brain Systems Fast System : Fast, automatic, frequent, emotional, stereotypic, subconscious Slow System: Slow, effortful, infrequent, logical, calculating, conscious A number of experiments purport to highlight the differences between these two thought processes, and how they arrive at different results even given the same inputs Terms and concepts include coherence, attention, laziness, association, jumping to conclusions and how one forms judgments.

131 Two Brain Systems

132 Test ALİ TOPU TUTTU VE KOŞTU

133 WHAT YOU SEE IS ALL THERE IS Fast system is very successful of creating memories Amount and quality of the data on which the story is based are largely irrelevant Fast System likes to jump to conclusions using the associative machine in the brain

134 Why? Jumping to conclusion is easy Save energy Removes ambiguity Provided comfort

135 Cognitive Ease REPEATED EXPERIENCE FEELS FAMILIAR CLEAR DISPLAY EASE FEELS TRUE PRIMED IDEA GOOD MOOD FEELS GOOD FEELS EFFORTLESS

136 Illusion of Remembering People are more likely to identify as true statements those they have previously heard (even if they cannot consciously remember having heard them), regardless of the actual validity of the statement In other words, a person is more likely to believe a familiar statement than an unfamiliar one.

137 Conjunction fallacy Phycologists gave subjects a short character sketch of a woman called Linda:, "31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti nuclear demonstrations". People reading this description then ranked the likelihood of different statements about Linda "Linda is a bank teller", and, "Linda is a bank teller and is active in the feminist movement". People showed a strong tendency to rate the latter (active feminist) However "Linda is both X and Y" can never be more probable than the more general statement "Linda is X". The explanation in terms of heuristics is that the judgment was distorted because, for the readers, the character sketch was representative of the sort of person who might be an active feminist but not of someone who works in a bank

138 Misperception of randomness In a sequence of coin tosses, each of which comes up heads (H) or tails (T), people reliably tend to judge a clearly patterned sequence such as HHHTTT as less likely than a less patterned sequence such as HTHTTH These sequences have exactly the same probability, but people tend to see the more clearly patterned sequences as less representative of randomness

139 Negativity Dominance Amygdala Threat center active on emotional states Information about threat travels via a superfast neural channel to the «emotion center» bypassing the visual cortex that supports conscious experience of seeing Brain responds quickly to survive No comparable mechanisms for «good» news Some similarity for signs of opportunity to mate and or to feed (advertisers use this)

140 Bad vs Good Brain responds quickly to symbolic threats Bad words : war, crime, vomit, cut, cockroach sinek küçüktür ama mide bulandırır Negative trumps the positive in many ways Success of relationships depends more on avoiding negative than seeking positive Good and bad hard wired at the brain Pain = bad / sweet = good

141 Choice Blindness Choice blindness is a phenomenon where people make a choice (choosing a picture they like), and then when the object of their preference is switched with another one, do not acknowledge the difference and tend to find explanations for this altered choice

142 Choice Blindness

143 Heuristics In psychology, heuristics are simple, efficient rules which people often use to form judgments and make decisions Heuristics usually govern automatic, intuitive judgments but can also be used as deliberate mental strategies when working from limited information or conflicting information

144 Applications of Anchoring People's valuation of goods, and the quantities they buy, respond to anchoring effects In one experiment, people wrote down the last two digits of their social security numbers. They were then asked to consider whether they would pay this number of dollars for items whose value they did not know, such as wine, chocolate, and computer equipment. They then entered an auction to bid for these items. Those with the highest two digit numbers submitted bids that were many times higher than those with the lowest numbers When a stack of soup cans in a supermarket was labelled, "Limit 12 per customer", the label influenced customers to buy more cans

145 Test SET A 40 parça SET B 24 parça Yemek tabağı 8 hepsi iyi 8 hepsi iyi Çorba tabağı 8 hepsi iyi 8 hepsi iyi Tatlı tabağı 8 hepsi iyi 8 hepsi iyi Fincan Fincan tabağı 8, 2si kırık 8, 7si kırık Eğer benzer kalite TL arasında ise, takımlara kaç TL verirdiniz?

146 Az Çoktur! Deneklere yemek takımları beraber gösterildiği zaman: A $32 B $32 Deneklere yemek takımları ayrı ayrı gösterildiği zaman: A $23 B $33 Hızlı sistem (Fast system) ortalama almayı seviyor!!

147 Prospect Theory Three bowl test: Left: ice water Right : warm water Center : room temperature Immerse hads in cold and warm water for one minute Then dip both hands in the middle bowl One hand will feel it cold, the other hot!!

148 Frames and Brain Subjects were asked to imagine that they are giving 50$ and bet on a the wheel of fortune: White: receive entire amount Black: loose everything Sure outcome: 20$ Same problem : KEEP 20$ or LOOSE 30$ Reality bound person wouldn t care But: FAST SYSTEM favors sure thing!!

149 Frames and Brain Trials on subjects for the following choices: Preferred sure thing in the KEEP version Preferred to gamble in the LOSS version Did not conform to the frame RECEİVE 50$ KEEP 20$ LOOSE 30$

150 Frames and Brain Amygdala was active when subjects were conforming to the frame Amygdala was accessed rapidly by emotional stimuli Brain region known to be associated with conflict and self control (anterior cingulate) was active when subjects choose the sure thing if when it was labeled LOSE Rational subjects no framing effects showed enhanced acticvity in the frontal area combining emotion and reasoning to guide decisons

151 Emotional Framing Statistics about lung cancer: Surgery vs radiaton therapy 5 years survival rate favors surgery Surgery is risky Experiment: Half of the physicians were given: One month survival rate is 90% Second half of physicians were given: 10% mortality in the first month Surgery was more popular in the first frame (84%) than in the second (50%)!!

152 Fast vs Slow Fast system: automatic thinking effortless Intuitive answers from heuristics No warning when unreliable Not constrained by capacity limits What you see is all there is: intensity matching, associative Source of errors and biases Slow system: logical thinking and deliberations effortful Checks Fast System but cannot distinguish between skill and heuristics Need to slwo down to work : but cognitive illusions are more difficult to recognize than perceptual illusions These systems do not really exist physically in the brain

153

154 Types of Magical Effects and Methodologies

155 Types of Magical Effects and Methodologies

156 Öğrendiklerimiz Düşünmek için beynimiz enerji harcar Enerji kısıtlıdır Düşünmek düşmeden yürümek veya yemek bulmak gibi işlere ayrılabilecek kaynakları kullanır Düşünmeden yapmak için beynimizin bağlantılarını değiştiririz

157 Öğrendiklerimiz Göz ve beyin (diğer duyu organları da) ayrıştırması kolayolmayan bir şekilde beraber çalışır Göz beyin pahalı bir kamera bilgisayar değildir Beyin bir şey görmez duymaz!! Beyin görsel veya diğer duyuları kullanarak «kendi gerçeğini» yaratır Beyin duyuları birleştirerek gerçek dünyanın bir «görüntüsünü» oluşturur

158 Öğrendiklerimiz Aklımız öngörü temelli çalışıyor Öngörü ile konuşuyoruz Algı edilgen bir duyu toplama değil, etkin yapılandırma Öngörülerimiz öğrendiklerimizden kaynaklanıyor

159 Öğrendiklerimiz Retinaya 2B bir görüntü düşmesine ragmen 3B algılıyoruz Algı ile gerçek aynı olmak zorunda değil Algı şüpheyi ortadan kaldırmayı amaçlıyor En doğru değil, en anlamlı sonuca yaklaşık 200 ms de ulaşmayı amaçlıyoruz Duyularınıza güvenmeyin