Intro and History. robby edwardsen

Transcription

1 1 robby edwardsen

2 Cognitive Psychology Introduction and History 2

3 SIMPLE QUESTIONS = Do without a calculator or paper use your mind. You have 1000, add 40, add 1000, add 30 again 1000 add 20, add again 1000 and finally 10. What is the result? 3

4 AN IMPORTANT QUESTION!!!! Does the Pope Wear underwear? 4

5 What is Cognitive Psychology? Cognitive Psychology is the scientific study concerned with the processes involved in acquiring, storing and transforming information (p.3). acquiring storing Transforming

6 Perception Knowledge Cognitive Psychology Attention Language Skills Memory Problem Solving 6

7 HISTORY OF COGNITIVE PSYCHOLOGY Cognitive Questions are as old as the dawn of human consciousness. Where do my thoughts come from? How do I know what is real and what is an illusion? How does my mind work? Do other people think as I do? 7

8 EPISTEMOLOGY: THEORIES OF KNOWLEDGE ACQUISITION Nativism ~ believe that knowledge is primarily (at least in some areas) acquired by a priori processes (e.g., innate or hardwired ; i.e., logic, wisdom, intuition, talents, innate abilities or disabilities). Empiricism ~ is generally a theory of knowledge emphasizing the role of experience, especially experience based on perceptual observations by the five senses. Nature Vs. Nurture Debate.

9 Philosophical Approaches (cont.) Ideas about Memory: Socrates - (Nativism) humans innately possessed knowledge, and that they only had to be led to discover what they already know. Aristotle learning is through experience (empiricism ~ tabula rasa)

10 Introspection Aristotle based much of this ideas about how the mind works on his observations of his own thought processes. 10

11 Philosopher s continued to address cognitive questions using introspection and logic. While they proposed interesting ideas, there was no method for testing theories to see if they explained real human cognitive processes. 11

12 Beginning of Psychology 1879 Wilhelm Wundt Father of the Science of Psychology - relationship between stimuli in the real world and our psychological experiences.

13 WUNDT S LAB 13

14 Wundt also used introspection, but of a different kind. Wundt's introspection was a rigidly controlled, arduous experimental procedure. Highly trained observers were presented with carefully controlled sensory events and asked to describe their mental experiences of these events e.g. metronome demonstration 14

15 VOLUNTARISM: Wundt proposed that our conscious experiences are due to the power of the will to organize the mind s content into higher-level thought processes. Apperception is considering a perception in relation to things you ve perceived in the past. 15

16 APPERCEPTION Example. A rich child and a poor child walking together come across the same ten dollar bill on the sidewalk. The rich child says it is not very much money and the poor child says it is a lot of money. The difference lies in how they apperceive the same event the lens of past experience through which they see and value (or devalue) the money. Christopher Ott 16

17 WUNDT FELT THAT INTROSPECTION COULD BE USED TO STUDY APPERCEPTIONS BUT COULD NOT BE USED TO STUDY THOUGHT PROCESSES, MEMORY PROCESSES, REASONING ETC. Wundt s student (Titchner) tried to use introspection to study the elements of thought rather than apperception which resulted in an argument about the existence of imageless thought. This debate demonstrated the limits of introspection and the technique was abandoned. 17

18 Problems with Introspection. - Many processes occur subliminally. - Confabulation - If reports are retrospective, we may forget parts of the process. - The process of introspection may effect the process.

19 e.g., In order to make sense of our thoughts, we often confabulate (make up) explanations for why we reach the conclusions we have. e.g., Subjects in a shopping mall were presented with an array of four sets of items (e.g., socks, nightgowns or pantyhose) and were allowed to choose one of them as a free sample. Even though all the options were identical they tended to choose the item on the right (Nisbett & Wilson, 1977). 19

20 When asked to explain why they chose the item they did, they came up with clearly confabulated explanations, such as their chosen item was softer or of better quality. 20

21 Behaviorism ( ) During this period studying cognitive Processes was very unpopular. Watson Classical Conditioning Skinner Operant conditioning Radical Behaviorism We cannot look inside the mind (introspect) so we cannot study these processes. To learn about human behavior we study ONLY observable behavior.

22 Psychology became the study of the relationship between Stimulus and Response Thorndike law of effect Learning occurs because of the consequences (rewards & punishments).

23 COGNITIVE REVOLUTION (1950'S TO 1970'S) Dissatisfaction with Behavioral Theories: Neo-behaviorist (e.g., Tolman) 3 routes to the food Strongest learning for A Least for C What if route is blocked at dotted line A? What if route is blocked at dotted line B?

24 In both cases Behaviorists would predict that the rats would take route B because it has more habit strength than route C. This is what happens when route is blocked at Block A. But what about when it is blocked at Block B? Taking Route B will not work. 24

25 When blocked at position B rats take Route C, indicating that the rat has developed a a metal representation (perhaps a cognitive map) of the maze.

26 Second Example: Latent Learning Rat run a maze once per day for 17 days. Group 1 - rewarded with food in goal box. Group 2 no reward in the goal box. Group 3 - Day 1 to 10 - no reward Day 11 to 17 reward.

27 Behaviorist s Predictions E r r o r s Days Learning begins when reward Begins

28 Actual Results Learning happens without consequences!!!

29 The Law of Effect is not always True. We do not simply repeat that which leads to rewards and avoid that which leads to punishment we are constantly seeking patterns even if there are no immediate consequences.

30 Other Influences that prompted the Cognitive Revolution WWII questions that behaviorists did not feel were important - attention - decision making - how do humans process information?

31 Computer as Metaphor for Mind - both encode, store, manipulate and use info - programs define rules, steps and stages for processing information. Artificial Intelligence

32 Cognitive Science s Official Birthday? September 11, 1956 MIT Conference brought together people from very different areas, linguistics, anthropologists, psychologists, computer programmers and philosophers, neuroscientists. They were all asking the same kind of questions and all agreed that behaviorism simply was not giving them answers.

33 Noam Chomsky (Linguist) - children s language errors go through phases of errors e.g., I goed to the store. Why? They have learned a concept about "past tenses" and they use it on all occasions.

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35 ULRIC NEISSER -focus of everyday applications of cognitive psychology. If X is an interesting memory phenomenon, psychologists avoid it like the plague. 35

36 CURRENT APPROACHES TO THE STUDY OF COGNITION Representationalism knowledge about the world is represented in our minds such that cognitive processes can operate on them. Arose form Information processing (computers). - Computers can represent information in digital code that it can operate on, so how does the human mind represent knowledge and operate on it? 36

37 Embodied Cognition cognitive processes provide a means of interacting with the world around us. The mind arises from the nature of our brains, bodies, and bodily experiences. George Lakoff Metaphors We Live By Semantics arise from the nature of the body. Our language indicates that we think metaphorically. 37

38 For example, embodied cognition researchers argue that much of our language comes from physical interactions during the first several years of life, such as the Affection is Warmth metaphor. John Bargh wanted to know if exposure to warm or cold stimuli would effect our judgments about others 38

39 Priming - John Bargh Study More From Bargh and his students Sitting in a hard chair can literally turn someone into a hardass. Holding a heavy clipboard leads to weighty decisions. Rubbing rough surfaces makes us prickly. Would-be car buyers who, when seated in a cushy chair, were less likely to drive a stiff bargain.

40 Biological Perspective (connectionist model) Brain as Mind - mind emerges from the complex networks of neural connections of the nervous system. 40

41 CONNECTIONIST NETWORKS - Parallel (many processes going on at the same time) Distributed (activity at several levels and areas of the network) Models 41

42 WHICH OF THESE APPROACHES ARE CORRECT? All of Them! 42

43 Reverse Engineering From Wikipedia, the free encyclopedia the process of discovering the technological principles of a device, object or system through analysis of its structure, function and operation. It often involves taking something apart and analyzing its workings in detail, usually to try to make a new device or program that does the same thing From Wikipedia, the free encyclopedia... In cognitive psychology the purpose is to understand the human mind and its interactions with the body and the physical world.

44 RESEARCH IN COGNITIVE PSYCHOLOGY Scientific Method Empiricism Determinism Testability Parsimony 44

45 RESEARCH METHODOLOGY Case Studies Correlate cases of brain injury or disease with behavioral symptoms. Localization of function - the idea that different parts of the brain do different tasks. 45

46 LIMITATIONS OF CASE STUDIES Correlational the researcher does not create the damage. These are not controlled studies. Very weak evidence of cause and effect. 46 Damage is rarely specific to one area of the cognitive system. Lack of generalizability

47 FAMOUS CASE STUDIES Phineas Gage 47 Broca s Aphasia Wernike s Aphasia

48 HM: CASESTUDY IN AMNESIA Henry Molaison suffered from profound amnesia as a result of surgery in 1953 to treat epilepsy. The surgeon removed a portion of Henry s temporal lobe, including parts of the hippocampus and amygdala, from both sides of the brain. Henry could remember much of his childhood: he knew his name and family history and he retained his intellectual abilities. However, he struggled to remember events from the 11 year period leading up to the surgery Henry also lost the ability to form new memories. 48

49 For 55 years Henry participated in numerous experiments. These studies have lead to a better understanding of memory and amnesia. 49

50 Correlational Studies Looks at the relationship between two variables. There is no independent variable (nothing is manipulated). E.g., differences in a skill between people with retrograde amnesia and non-amnesic controls. - Does not give evidence of cause and effect. - Does allow for conclusions of predictability 50

51 Experimental Method Independent Variable - manipulated under the control of the researcher. Dependent Variable All other variables are held constant Only TRUE experiments allow for conclusions of cause and effect! 51

52 COMMONLY USED MEASURES IN COGNITIVE PSYCHOLOGY Accuracy E.g., How many words can a person recall from a list they studied 2 weeks ago? Are witnesses able to accurately recall the details of a motor accident they viewed on video? Are people able to solve special problems? Do hints increase their accuracy? 52

53 Herman von Helmholtz and Neural Speed Video turn off sound (40 secs is enough) Neural speed is constant (1 meter/sec) Measure of mental processes? More complex neural processes will take more time. 53

54 Franciscus Cornelis Donders (1868) Reaction time Experiment Simple RT and Choice RT Measured the time required to decide.

55 A modern version of Donders (1868) reaction time experiment. (a) the simple reaction-time task; and (b) the choice reaction-time task. For the simple time reaction text, the participant pushes the J key when the light goes on. For the choice reaction time test the participant pushes the J key if the left light goes on, and the K key if the right light goes on. The purpose of the Donders experiment was to determine the time it took to decide which key to press for the choice reaction time test. Donders Inference: decision took.1 second

56 TIME/ACCURACY TRADE-OFF For many tasks, increasing speed increases errors. In some studies this relationship is of interest. One of the big challenges of studying cognitive processes is finding way to meaningfully measure them. Good cognitive research requires creativity in measurement and hypothesis testing. 56