CogSci 1 Intro-2 PDF

Introduction to Cognitive Science N.B.: Much of PowerPoint lecture notes is taken from and corresponds to the Bermudez text © 2024 Davina Chan STUDENTS ARE PROHIBITED FROM RECORDING COURSE CONTENT AND FROM POSTING COURSE POWERPOINTS ONLINE IN ANY WAY, SHAPE, OR FORM WITHOUT EXPLICIT WRITTEN PERMISSI...

Introduction to Cognitive Science N.B.: Much of PowerPoint lecture notes is taken from and corresponds to the Bermudez text © 2024 Davina Chan STUDENTS ARE PROHIBITED FROM RECORDING COURSE CONTENT AND FROM POSTING COURSE POWERPOINTS ONLINE IN ANY WAY, SHAPE, OR FORM WITHOUT EXPLICIT WRITTEN PERMISSION FROM THE PROFESSOR I. Cognitive Science: Interdisciplinary study of the mind and cognition II. History of Cognitive Science A. Tolman’s cognitive mapping: Learning without reinforcement B. Lashley’s view of complex behaviors as products of planning and organization C. Turing machines: Information processing as algorithmic process D. Chomsky’s transformational grammar: Analyzing underlying structures of language E. Miller’s “Magical Number Seven”: Perceptual systems as informational channels with built-in limits F. Broadbent’s filter model of attention III. SQ3R technique for efficient reading IV. Cognitive Science/Psychological Research A.Two basic types of research design 1. Correlational 2. Experimental a. The experimental method b. Independent and dependent variables B. Informed consent C. Within- vs. between-subjects design D. Counterbalancing Cognitive Science: Study of the mind and cognition that integrates a number of different academic disciplines Neuroscientists study the mind’s biological machinery Psychologists directly study mental processes, such as perception and decision-making Computer scientists explore how those processes can be simulated and modeled in computers Philosophers ask critical questions about the nature of the mind Evolutionary biologists and anthropologists speculate about how the mind evolved v The job of cognitive science is to provide a framework for bringing all those perspectives on the mind together The various academic disciplines that comprise cognitive science use different methods For example, for philosophers – particularly in the so-called analytic tradition, the tradition most relevant to cognitive science – the unity of their discipline comes from − Certain problems that are standardly accepted as philosophical − A commitment to rigorous argument and analysis In contrast, the unity of psychology comes from a shared set of experimental techniques and paradigms Different branches of neuroscience employ different tools appropriate to the level of organization at which they are studying the brain − These tools and techniques vary in o Spatial resolution (y-axis): the scale on which they give precise measurement o Temporal resolution (x-axis): time intervals to which they are sensitive Summary of Disciplines and Methods Discipline Method Philosophers Deductive reasoning Psychologists Scientific method Cognitive psychologists Modeling AI researchers Computer models Neuroscientists Case studies, lesion methods, brain imaging Roboticists Build and test machines v Ideally, Cognitive Science would involve integration of these disparate methods ✧ Conclusions derived from Western psychology experiments may not be very representative of humanity as a whole Typical research participants tend to be WEIRD – Western, Educated, Industrialized, Rich, and Democratic ✧ In part for this reason, Cognitive Science includes the study of anthropology and cultural differences The Space of Cognitive Science The different parts of cognitive science are distributed across a three-dimensional space where The x-axis marks the different cognitive domains that are being studied The y-axis marks the different tools that might be employed (ordered roughly in terms of their degree of spatial resolution) The z-axis marks the different levels of organization at which cognition is studied History of Cognitive Science Cognitive science has evolved considerably in its short life Priorities have changed as new methods have emerged – and some fundamental theoretical assumptions have changed with them Ø Example: − For a long time in the history of cognitive science, it was widely held that we are better off studying the mind by abstracting away the details of what is going on in the brain − This changed only with the emergence in the 1970s and 1980s of new technologies for studying neural activity and of new ways of modeling cognitive abilities v We will be looking in this section at some key discoveries and theoretical advances in the field ✧ Attempts to understand mind go back at least to the ancient Greeks Discovered laws of learning and memory, e.g., method of loci Described human thinking in terms of mechanical manipulation of symbols ✧ Study of mind remained province of philosophy until 19th century ✧ In 1879, Wundt established first psychology laboratory Studied mental processes systematically using technique of introspection to systematically observe one’s own sensations and report them as objectively as possible ✧ Within decades, however, experimental psychology became dominated by behaviorism, a view that virtually denied the existence of the mind Psychology should study relation between observable stimuli and observable behavioral responses Mind was banished from respectable scientific discussion ✧ However, in 1950’s, cognitive psychology began to emerge as a result of New research on memory, child development, linguistics Development of computer science Disenchantment with behaviorism “Computers in the future may weigh no more than 1.5 tons.” Popular Mechanics, 1949 Learning without Reinforcement: “Insight” in Rats Edward Tolman’s experiments on cognitive mapping in rats (1930) showed that learning does not necessarily follow a strict behaviorist view: Behaviorists maintained that − Learning results from stimulus-response associations o Thus, no learning should occur if a response is not made − Also, learning requires reinforcement and/or punishment However, experiments with maze learning showed that learning can occur even when 1) when no reinforcement is received; and 2) no response is made Ø Cognitive Map Experiment #1: − One group of rats was allowed to run through T-maze themselves − Second group was carried through maze in a wire basket pushed by experimenter ➜ When allowed to run freely following training, rats in second group were just as adept in reaching goal (location of cheese) ☞ The rats were able to learn without making bodily responses and without reinforcement (latent learning) Ø Cognitive Map Experiment #2: − Rats were trained to run a maze − Then rats were faced with a change in their starting place, or with blockades placed in their usual routes ➜ Rats behaved as if they are able to consult a map and work out best available route to goal ☞ When rats explore a maze, they acquire a map-like knowledge of its spatial layout, not just a sequence of bodily responses involving left and right turns v These experiments suggest that learning is not just a matter of stimulus-response associations, but must take into account the organism’s mental processes − More specifically, even very basic types of behavior, such as the behavior of rats in mazes, seems to involve storing and processing information about the environment – rather than just chained sequences of conditioned reflexes Planning and Organization in Complex Behavior Karl Lashley wrote a paper (1951) stating that complex behaviors should be thought of as products of planning and organization Ø Ex: Walking over to the table to pick up a glass of water is implemented by: o Walking plan o Reaching plan − These in turn can be broken down into simpler plans ☞ Behaviorism relies on a series of linked responses or serial processing, but many of our activities use top-down, as well as bottom-up, processes (e.g., planning, predicting, etc.) Lashley’s paper contains seeds of two ideas that have proved very important for cognitive science Task analysis: we can understand a complex task by breaking it down into a hierarchy of more basic subtasks Subconscious information processing: although we are often conscious of our high-level plans and goals (what goes on at the top of the hierarchy), we tend not to be aware of the information processing that translates those plans and goals into actions Ø Ex: picking up the glass of water requires calculating very precisely the trajectory our arm must take and the degree to which our hand is open to take hold of the glass, but these calculations are carried out by information-processing systems that operate far below the threshold of conscious awareness Development of Computational Model of Mind Alan Turing, in article published in 1936-37 Conceived of information processing as an algorithmic or rule-based calculation process (Turing machine) Together with advances that were made in designing and building digital computers during and after World War II, this led to development of view that cognition involves an algorithmic process of information processing A Turing machine has a set of instructions (machine table) that determines what the machine will do when it encounters a particular symbol in a particular cell, depending upon which internal state it is in Linguistics and Analysis of Language The transformational grammar proposed by Noam Chomsky (1957) provided a way to analyze our ability to speak and understand language Distinguished between − Deep structure of a sentence o Underlying meaning of the sentence o How a sentence is built up from basic constituents according to basic rules Ø Ex: Every sentence is composed of a noun phrase (e.g., “John”) and a verb phrase (e.g., “has hit the ball”) − Surface structure of a sentence: the actual organization of words in a sentence or its superficial appearance o This is derived from the deep structure according to the principles of transformational grammar Ø Ex: “The ball has been hit by John” from “John has hit the ball” Implications: − Sophisticated cognitive ability, such as use of language, involves stored bodies of information (about phrase or deep structures and transformation rules) − These bodies of information can be analyzed or manipulated algorithmically ☞ We can analyze the underlying structures of basic cognitive abilities How Much Information Can We Handle? George Miller’s article on “The Magical Number Seven, Plus or Minus Two” (1956) Drew attention to evidence that human perceptual systems (e.g., vision and audition) are information channels with built-in limits We can only process around seven items at the same time ➜ Proposed information processing bottleneck At the same time, Miller identified ways of working around these limits, e.g., by chunking information The Dichotic Listening Task & the Filter Model of Attention Donald Broadbent formulated one of the first information-processing models in psychology (1958) Ø Based on dichotic listening experiments (shadowing task): − Participants are instructed to repeat message played in one ear while ignoring message played in other ear − Participants are very good at filtering out irrelevant information: they fail to notice even changes in language in the unattended ear or words that have been repeated dozens of times – However, they are usually able to pick out the gender of the speaker, words like “Fire,” and their own name (“cocktail party effect”) v In general, people tend to consciously attend to one source of information and ignore other sources, but people vary in degree to which they focus attention and ignore distractions Results of dichotic listening experiments supports filter model of attention: everything is picked up on some level, but at any given moment, we focus our awareness on only a limited aspect of all that we are experiencing Broadbent proposed a flowchart model of selective attention to explain these results This type of flowchart model has become a standard way for cognitive scientists to describe and explain different aspects of cognition − Assumption that system is pursuing a goal − What is programming the filter is information about the sorts of things that have led to that goal being satisfied in the past ➜ Implications: We can understand how a cognitive system as a whole works by understanding how information flows through the system SQ3R Technique for Efficient Reading Survey Scan material Read headings, figures, summaries Question Pose questions to yourself Read Look for answers to questions as you read Read actively, not word by word (key to speed-reading!) Recite Practice rehearsal (tell someone about the material) Review Go over answers to questions Review material again a day or several days later Fallacies You have to read every word. The slower you read, the higher your comprehension. It’s a sin to skip around when you are reading. Cognitive Science/Psychological Research The group project for this class involves Designing and running a cognitive science-related experiment OR Submitting a proposal for development of a new AI product The material in the following section will be of particular importance to those of you choosing the research study option Two basic research designs Correlational Design (comparative) Experimental Design (manipulative) Correlational Design (comparative) – Used to assess relationship (e.g., through a survey), between two factors such as... o TV watching and obesity o SAT scores and GPA o Learning ability and alcohol consumption o Breast-feeding (vs. bottle-feeding) and IQ ☞ Note that correlation does not imply causation! o A correlation only implies an association o It is not possible to conclude that one factor causes another factor from a correlation o First factor may be caused by second factor (rather than vice versa), or the association may be caused by a third factor ØExamples: − Ice cream consumption and murder rate − Pellagra Experimental Design (manipulative) – Measures behavior under controlled (e.g., laboratory) conditions – Manipulates conditions within an experiment Experiment Hypothesis: Make prediction: > Eating chocolate will facilitate performance on a memory test Method: Under controlled setting (laboratory), vary conditions: > Half the participants learn list of words after eating chocolate Results: Measure and analyze performance across experimental conditions > Statistical analysis shows that chocolate does not enhance memory performance Findings: Confirm or disconfirm hypothesis > Hypothesis disconfirmed Theory: Make generalization about psychological phenomenon ➔ Generate new hypothesis > Eating chocolate will only facilitate memory performance in chocoholics Experimental Variables Independent variables: factors in an experiment that are manipulated ☞ We must manipulate only one independent variable at a time Dependent variables: factors that are measured in an experiment (the data) Confounding variables: factors not considered and uncontrolled that may have affected the results Important Notes Regarding Research Project Informed Consent Please read through the “Informed Consent Guidelines” file posted on bCourses carefully! Note in particular that: − The class project must not involve any type of risky behavior, such as drug use − Your class project may not include a survey that asks questions involving sensitive information, such as drug use, sexual activity, or psychological disorders − The class project may not involve children − The class project should be identified to participants as a class assignment, rather than as “research” − All data obtained must be destroyed at the end of the term − The research findings from the class project may not be submitted for publication or dissemination outside of class Within- vs. between-subjects design Within-subjects design: each participant completes each condition in the experiment (e.g., exercising and not exercising) Between-subjects design: separate participants complete each condition in the experiment (e.g., exercising or not exercising) ★ If you know that you will likely only be able to recruit a relatively small number of participants for your experiment, to boost your chances of finding a significant difference between groups, it would be best to use a within-subjects design Counterbalancing: If you are conducting a within-subjects experiment, you will probably need to counterbalance the order of presentation of your conditions Ø Ex: If you are conducting a two-week-long within-subjects experiment on the effects of listening to music before bed on cognitive performance the next day, you need to make sure that: − Half of your participants listen to music before bed the first week but not the second week − The other half do not listen to music before bed the first week but listen the second week Video Reference Video excerpted from: Discovering Psychology: Past, Present, and Promise https://www.learner.org/series/discoveringpsychology/past-present-and-promise/