Lecture Notes for Exam 1

I. Basic Principles of Memory: The Forgetting Curve A. Ebbinghaus's (1845) Work -Ebbinghaus memorized (relearned) lists of nonsense words (QEH) - he would then calculate his savings score with the savings score equation What he found out! the forgetting curve -forgetting is rapid initially it is important to review what you learned soon after the learning took place B. The Benefit of Repeated Learning ? Repeated learning leads to more durable memory ? How you repeat matters!! ? There are two kinds of repitition ? Elaborative Rehearsal ? much more effective than maintenance (rote) rehearsal ? Elaborative rehearsal is when you relate what you are learning to what you already know ? Example: creating stories, mnemonic devices ? Maintenance (rote) Rehearsal ? not as effective ? Ex: Flashcards ? Expanding retrieval practice is highly effective ? steadily increasing the time intervals between successive sessions II. The major schools of psychology A. Structuralism German, more uptight "school" Influential figure: Wilhelm Wundt --> father of modern scientific psychology Main Focus: understanding the structure of the mind by identifying its simplest unit How did they understand the structure of the mind? "Analytic Introspection" under controlled conditions Trained observers describe their conscious experiences in response to stimuli What cognitive psychology inherited from Structuralism: Emphasis on the structure (or components) of the mind Rigorous experimentation under controlled conditions What cognitive psychology rejected from Structrualism: Introspection as the main research method B. Functionalism American, more relaxed "school" Influential Figure: William James Main Focus: Understanding the adaptive function of behavior by analyzing mental processes in real life situations Why does the mind work the way it does? Main Method: reflection over naturalistic situations What cognitive psychology inherited from Functionalism: Great questions and interesting theoretical ideas Emphasis on the functions of the mind What cognitive psychology rejected: Their too casual and too reflective style of research C. Behaviorism: The scientific study of observable behavior Did not believe in the mind Studied how stimulus in the environment influence the organism's response Influential Figure: John B. Watson: early B.F. Skinner: later Main Method:Rigorous experimentation What cognitive psychology inherited: Rigorous experimentation under controlled stiuations Objectivity in research What cognitive psychology rejected: Rejection of mental processes Too much emphasis on animal experimentation D. Factors that Contributed to the Cognitive Revolution Studying complex human behavior Modern Linguistics challenged behaviorists view of language Computer Science Provided an analogy of the human mind as "computers" Basic Assumptions of cognitive psychology Mental Processes exist! Mental processes can be studied scientifically By examining reaction times and accuracy of processing By examining brain indices of the mind Event Related Potentials (ERP) Positron Emission Tomography (PET) Functional Magnetic Resonance Image Human beings are active Information Processes LECTURE 2 I. Basic Principles of Memory: The Generation Effect Information that you generate is remembered better than information you simply read of hear Avoid simply reading notes and textbooks test yourself during learning or have a friend test you II. What is pattern recognition? A. Pattern recognition: The process of perceptually identifying "things" in the environment (e.g. words, objects, faces) This is very easy for humans, but difficult for computers B. The Visual System: The Eye 1. The retina recieves an image of a stimulus 2. The receptor cells in the retina (rods and cones) convert light energy into neural impulses C. Receptor cells in the retina Rods: concentrated in the periphery (outside of fovea) Operate at low light intensities good for light vision Lead to colorless sensation Cones: concentrated in foveal region (center) respond at high levels of illumination good for day vision Responsible for color sensations 3 types of cones sensitive to different wavelengths III. The Visual System: From Retina to Visual Cortex The optic nerves carry the neural impulses to the primary visual cortex Some optic nerve fibers cross over at the OPTIC CHIASM Stimuli in the Left Visual Field go to the Right Hemisphere Stimuli in the Right Visual Field go to the Left Hemisphere B. The Visual System: Two Cortical Pathways The dorsal pathway (or "where" pathway) Goes to the parietal lobe Processes spatial information (e.g. location, spatial) The Ventral Pathway ("what" pathway) Goes to the temporal lobe Processes visual information (e.g. color, shape, texture) C. Hemisphere Differences Functions dominant in the left hemisphere many aspects of language processing The processing of "local" information(individual elements) Functions Dominant in the right hemisphere Various aspects of visuospatial processing The processing of "global" information (overall shape) D. Studies with Split-Brain Patients: The Logic Recall that: Stimuli in the left visual field go to the right hemisphere Stimuli in the right visual field go to the left hemisphere There is also a cross-over for motor control (contralaterality) IIII. Four types of patter recognition theories 1. Template Matching Matching the pattern against prestored templates Strenghts: works well for simple situations (e.g. numbers on checks) Weaknesses: may not be flexible enough to handle variability a huge number of templates may need to be stored unlikely to be correct for human pattern recognition 2. Prototype Matching Matching the pattern against extracted prototypes (= the best or most typical example) Humans are good at extracting prototypes Strengths: Resolves the "storage requirement" problem of template matching Allows more flexibility than template matchign Weaknesses: one prototype per pattern may not be enough for flexible pattern recognition unusual views 3. Feature Analysis matching the pattern against stored knowledge of objects features (e.g. Pandemonium model) Some neurons have been shown to be sensitive to features LECTURE 3 I. Basic Principles of Memory: Distributed Learning Distributed (spaced) learning is more effective than massed learning (Cramming) This is true for fact learning and skill learning (studying for a test and learning to type) AVOID CRAMMING II. Pattern Recognition A. Pandemonium Model Each group of "demons" doing their own jobs, focusing on the features in each letter One directional flow of information no feedback from higher level demons Strengths: Features clearly play a role in letter recognition Weaknesses: may not be able to deal with variability (e.g. handwriting or distorted letters) Different letters could share the same pattern EX: Two vertical lines, one horizontal line, 4 right angles. H It B. Structural Description Focuses on features! but also specifies the structural relationships (or spatial relationships) among them C. Recognition by components (RBC) or Geon Theory Each object can be decomposed into basic elements called "geons" we recognize objects in terms of these geons and their configurations Strengths: Extends feature analysis to the recognition of objects Can explain some experimental data well Weaknesses: Some doubts about geons being the "basic" features May not be applicable to the recognition of: fuzzy objects (clouds, fire, water), faces III. Theories of Pattern Recognition A. Bottom Up Theories Common Problems of Bottom-Up Theories context and expectation can have powerful influences in pattern recognition Bottom-Up theories cannot explain such top-down effects (the influence of context, knowledge and expectation on perception) B. Bottom-Up vs. Top-Down Processes Bottom-up (data-driven) processes Processes that are purely driven by incoming stimuli (one directional) Top-Down Processes Processes that are driven by our knowledge, expectations, or context Both bottom up and top down processes are important C. Top-Down Processes Top-Down processes are mental processes that are guided or driven by our knowledge, expectations, or context Top-Down processes are not your memory, or your expectations per se D. Some Lab-Based Top-Down Effects Cog-Lab #1 Single letters are better identified in words than non-words or individually LECTURE 4 I. Basic Principles of Memory: Organization Better organization leads to better memory Pay attention to the structure of what you try to learn Keep your notes organized How can we explain the word superiority effect? Interactive Activation model of word Recognition A. Interactive Activation Model Similar in the pandemonium model in that: There are different levels Each node does its own job Different from the pandemonium model in that: The nodes in IAV compete and try to inhibit one another It has bi-directional flow of information (bottom-up top-down) Pandemonium model is only bottom-up The top-down signal from the word level leads to the word superiority effect II. Different types of patter recognition disorders Letters and Words: Disorder: Alexia Objects: Disorder: Visual Agnosia Faces: Disorder: Prosopagnosia A. Visual Agnosia Impairment in the ability to recognize objects despite intact ruidmentary perceptual abilities Two types of visual agnosia: 1. Apperceptive Agnosia: cannot discriminate between objects cannot copy/match simple shapes 2. Associative Agnosia: can copy and match simple shapes line by line still fail to recognize object B. Prosopognosia Impairment in the ability to recognize faces III. Different Types of Patterns How many different subsystems are necessary to support the recognition of these different types of patterns? 1. Holistic (global) analysis crucial for face processing important for object processing 2. Analysis by parts crucial for word processing important for object processing