Slide 1“neuroenhancing drugs”Slide 3Slide 4What is attention for?Selecting informationSlide 7Visual AttentionSlide 9Slide 10Slide 11Attention also enhances perceptionSlide 13Attention helps integrate informationBinding problemTwo visual pathways (what & where/how systems)Columnar organizationDistributed codingSlide 19Slide 20Attention and Figure-ground segregationAttention and 3D structureSlide 24Slide 25Damage to the parietal lobe creates binding errors.Slide 27Slide 28Feature integration theoryWhat can you predict from this theory?DemonstrationSlide 32Slide 33Slide 34Slide 35Illusionary conjunctionsVisual search experimentsSlide 38Slide 39Slide 40Feature binding and attention (Treisman, 1988)Feature search vs. conjunction searchGenerality of the results: SExperiments:Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Some problems with FITThe physiology of attentionSlide 53Binding problem and schizophreniaAttention and AutismSlide 56(Q3) Are the male brain and the female brain different? If so, how? (Q4) Why are there much more autistic boys than girls?male brain vs. female brainSlide 59Slide 60Slide 61The extreme male brain theory of autism (by Baron-Cohen)Slide 63ch 6 1Sensation & PerceptionCh. 6: Visual Attention© Takashi Yamauchi (Dept. of Psychology, Texas A&M University)Main topicsBinding problemFeature integration theorySynchrony hypothesisThe physiology of attentionch 6 2“neuroenhancing drugs”•http://www.newyorker.com/reporting/2009/04/27/090427fa_fact_talbotch 6 3•A young man I’ll call Alex recently graduated from Harvard. As a history major, Alex wrote about a dozen papers a semester. He also ran a student organization, for which he often worked more than forty hours a week; when he wasn’t on the job, he had classes. Weeknights were devoted to all the schoolwork that he couldn’t finish during the day, and weekend nights were spent drinking with friends and going to dance parties. “Trite as it sounds,” he told me, it seemed important to “maybe appreciate my own youth.” Since, in essence, this life was impossible, Alex began taking Adderall to make it possible.ch 6 4Adderall, a stimulant composed of mixed amphetamine salts, is commonly prescribed for children and adults who have been given a diagnosis of attention-deficit hyperactivity disorder. But in recent years Adderall and Ritalin, another stimulant, have been adopted as cognitive enhancers: drugs that high-functioning, overcommitted people take to become higher-functioning and more overcommitted. During his college years, Alex took fifteen milligrams of Adderall most evenings, usually after dinner, guaranteeing that he would maintain intense focus while losing “any ability to sleep for approximately eight to ten hours.”ch 6 5What is attention for?•Selecting information•Enhancing information•Combining information•What role does attention play in combining/integrating information?•What physiological mechanism underlie the integrative process?ch 6 6Selecting information•The retina receives so much information.ch 6 7•Attention helps select information.•This is necessarily because of the way the eye is structured.–Most cones reside at the fovea.–To get accurate information about a scene, we need to select carefully particular parts of a scene.ch 6 8Visual Attention•Visual attention and eye movement•Eye tracker•Eye tracking machine and demo–http://www.youtube.com/watch?v=lGehsY7pcrcch 6 9ch 6 10ch 6 11ch 6 12Attention also enhances perception•If we don’t attend, we lose information. •If we attend, we understand better.ch 6 13•Change blindness–http://viscog.beckman.illinois.edu/flashmovie/12.phpch 6 14Attention helps integrate information•Binding problem•Feature integration theorych 6 15Binding problemch 6 16Two visual pathways (what & where/how systems)Image from Neuroscience, 2nd Ed. (2000).ch 6 17Columnar organization•Neurons that respond to the same orientation are packed in the same columnImage courtesy of Dr. Paul Wellman and Neuroscience, 2nd Ed. (2000).ch 6 18Distributed coding Combining inputch 6 19Binding problem•The modular organization of the brain poses an essential problem.–How does the brain combine information?–How does it bind features that are processed separately?ch 6 20•Feature integration theory •by Treisman & Gelade–Attention plays a central role in solving the binding problem.–Attention helps organize information.ch 6 21Attention and Figure-ground segregationDepending on where you look at, the figure and the ground switch rapidly. Attention plays some role in determining the figure and the ground.ch 6 22Attention and 3D structureDepending on where to look at, you get different kinds of 3D perception.ch 6 23ch 6 24ch 6 25ch 6 26Damage to the parietal lobe creates binding errors.ch 6 27ch 6 28Copies of the black (A) and the white (B) vertical contour.Copies of the black (A) and the white (B) diagonal contour.ch 6 29Feature integration theory•Attention combines the information from the what and where systems.ch 6 30What can you predict from this theory?•If you can’t attend, you can’t combine information. Illusionary conjunctionch 6 31Demonstration•I will show you a scene quickly.•Report first the black numbers.•Report what you see at each of the 4 locations.+++ch 6 32•Report first the black numbers.•Report what you saw at each of the 4 locations.ch 6 33+++++ch 6 34ch 6 35ch 6 36Illusionary conjunctions•We tend to put different features from different objects together.•brain damaged patients (parietal lobe) show illusionary conjunctions even when they view the stimuli for 10 seconds.•Balint syndrome–http://www.youtube.com/watch?v=4odhSq46vtUch 6 37Visual search experiments•Feature search–You look for a single feature. you don’t need attention•Conjunction search–You need to combine two or more features (color and orientation) you need attention•Looking for the targetch 6 38Visual search experimentsColor OrientationT: green horizontalD: green vertical•Looking for the target Color OrientationT: green horizontalD1: green verticalD2: red horizontalch 6 39FindWhich is more difficult?ch 6 40FindWhich is more difficult?ch 6 41Feature binding and attention (Treisman, 1988)Experiments:Task:Given a stimulus frame containing visual items, subjects were asked to indicate whether or not a target item was present in the frame.ch 6 42Feature search vs.