Cognitive Psychology Exam 1 Study Guide

Cognitive Psychology Exam 1 Study Guide Chapter 1: Introduction to Cognitive Psychology Cognitive psychologists…  study mental activities (i.e.—attention, memory, learning, thinking, decision making, and language comprehension) Core Topics Lower order cognition  deal with sensory input to system through perception and attention Memory  deals with learning, knowing, and remembering Higher order cognition  deals with reasoning, decision-making, and problem-solving What We Study… Processes  “What are people doing?” and “What are they aware of?” Structures  “What are the parts of the mind?”; “How do they work?”; “How do they limit us?” Localizations  “Where in the brain do these processes and structures exist?” Thought processes  some are conscious (ex. Thinking “three times two”); some are unconscious (ex. Retrieving the answer “6” in response to 3 * 2) Mental Capacities Computer analogy  “mind is like a computer” (hardware = parts, memory, processor, etc.); there are hardware limits within a computer; states that we have “fixed parts” (like CPU hardware, we have measureable limits) Broadbent  1955; selective attention—we cannot attend to everything out there Miller  1956; short-term memory; the “magical number” (7 +/- 2); why phone digits are 7 digits long Map analogy  maps are symbols (they represent something); whatever is not represented on a map is not available to you Representations Mental representations  we use symbols of the world (letters, words, mental images, etc.); encode only some features of the world (similar to a map); may constrain thought; idea is from Gestalt theorists (early 1900s) Cont’d  the “whole is greater than its parts”; representations are not just collections of pieces (we have a perspective as well); ex. Old lady or young princess? Cont’d 2  different representations can lead to different thoughts and insights (ex. Mutilated checkerboard problem) Map metaphor (cont’d)  we represent information in our minds; representations contain “hidden” information (more than just the parts); representations constrain what we think Methods for Studying the Mind Behavioral observation  watch people perform a task; common measure— % correct; “do people do better in condition A or condition B?”; may provide clues about representation and process Introspection  thinking on your own thoughts; Wilhelm Wundt (“what elements make up conscious experience?”) Problems of introspection  there can be conflicts between observers (“imageless thought”); modern descendant of introspection is verbal reports methodology (aka “thinking out loud) Reaction times  mental activities take time F.C. Donders  first to measure reaction times; shocked left or right foot (people were either prepared or unprepared for the shock); time difference was 1/15th of a second Hermann Ebbinghaus  first to scientifically study human memory; studied nonsense syllables (ex. DAX) rather than actual words; discovered laws of forgetÝng; Recall  target absent, you must remember it on your own Recognition  target is presented to you (along with other distractors), you must identify whether you have seen it before or not Research Methods Behavioral measures  reaction time and proportion correct Verbal protocols  concurrent, think aloud protocols Physiological measures  CT, TMS, ERP, PET, fMRI Also…  Memory tests and lesion studies (Broca’s and Wernicke’s areas) Lesion studies  Paul Broca and Carl Wernicke; brain damage—a “lesion” or cut in the brain Broca’s area  causes speech production trouble Wernicke’s area  causes comprehension problems CT Scan  computerized tomography; structural imaging of neurological damage; x-ray taken around head; absorption of x-ray indicates tissue density (light-colored area—high density; dark-colored area—liquid) Transcranial Magnetic Stimulation (TMS)  create temporary “lesions” by applying a very strong magnetic field; shuts off specific parts of the brain temporarily Double dissociations  “How do we know that one cognitive function is served by one brain region, whereas a different function is served by another region?” Example of DD  one variable affects Task A but not Task B and another variable affects Task B but not Task A; lesion in one area causes speech production deficit; however, lesion in another area causes speech comprehension deficit Brain Structures/Function  various parts of the brain do not work independently of each other; they communicate with each other; massive parallel processing throughout the brain to perform mental functions Example in perception  ‘what pathway’—processes identity of perceived object; ‘where pathway’—processes location of perceived object Example of language processing  speaking a written word involves at least 5 neocortical areas; each area performs certain functions; the areas coordinate their actions; the brain acts as an integrated system Electroencephalogram (EEG)  measures electrical activity through electrodes attached to the skull; can infer the state of the brain by the frequency of the waves Event-related potential (ERP)  brain’s electrical response to a stimulus event; ERP doesn’t show where in the brain a process takes place, it shows when a particular brain activity takes place (in response to an event); either P₃₀₀ or N₄₀₀ (positive peak in the EEG signal occurring 300 ms after onset of attention-getÝng stimulus; negative peak in the EEG signal occurring 400 ms after onset of attention-getÝng stimulus) Functional Magnetic Resonance Imaging (fMRI)  when neurons are working, they need energy in the form of oxygen; fMRI uses magnetic field to trace changes in the concentration of oxygen in the blood, so you know where the brain is working hard Positron Emission Tomography (PET)  small amounts of radioactive isotopes are placed in the blood; sensors detect areas of high metabolic activity in the brain (ex. Changes in blood flow); different tasks show distinct activity patterns Ergonomics  The design of machines and equipment for human use, and the determination of the appropriate human behaviors for the efÏcient operation of the machines Human factors research…  does two things: 1) improve machines so they are easier/safer to use; 2) find out why the humans make mistakes and train them not to make those mistakes Types of Errors Mistakes  failure to formulate the right intention; (ex. you think your house guests like wafÒes, but actually they told you they want eggs) Slips  the right intention is formed, but it is carried out incorrectly (ex. you intend to pour syrup on the wafÒes, but instead pour orange juice) Lapses  skipping a step by mistake (ex. you forget to add salt to the wafÒe batter) Chapter 2: Sensation and Perception Sensation  reception of stimulation from the environment and its initial encoding into the nervous system; sensory info—tactile, gustatory, visual, olfactory, auditory Perception  process of interpreting and understanding what is sensed; uses previous knowledge to interpret what is registered by the senses Understanding  accessed memory to recognize the objects; can often fill in the missing parts without actually seeing them (ex. Obstructed airplane picture) Visual Perception  it is common to differentiate between early processing of info in the visual stream and later processing of info (ex. Blotted, unclear picture of dalmation) Perception and Agnosia Agnosia  an inability to recognize visual objects that is neither a function of intellectual loss nor a loss of basic sensory abilities; 2 types—apperceptive and associative Apperceptive agnosia  aka visual agnosia; early perceptual processes are disrupted; able to register visual information but cannot combine that information to form a perceptual experience/gestalt; unable to distinguish visual shapes (have trouble copying); however, can rely on touch, smell, etc. to recognize an object (they know what it is if they touch it); posterior parietal region in right hemisphere Associative agnosia  aka object agnosia; later processes (pattern recognition) are disrupted; form of loss is like “recognition without meaning”; failure to assign meaning to an object they can clearly see; patients suffering are able to reproduce an image through copying but fail to recognize/name the object (ex. Anchor as an umbrella); junction of occipital/temporal lobes in both left/right hemisphere Ap. Agnosia (summary)  object recognition fails because of difÏculties in identifying the visual features of a perceptual category As. Agnosia (summary)  object recognition fails because of difÏculties in identifying the functional features that define a semantic category Pattern Recognition Template Matching Theory  assumes that a retinal image of an object is faithfully transmitted to the brain, and that an attempt is made to compare it to various other stored patterns (or templates) to find a match; comparing a stimulus to a large number of literal copies stored in memory to find a match; used often in machine pattern recognition; ex. Letter ‘K’ (different styles of handwriting) Feature Analysis Theory  stimuli consist of combinations of elemental features; we can perceive an object because what we store in our long-term memory are its parts/features; we compare retinal images and see what object in longterm memory has most features that match the object; features of alphabetical letters Psychological evidence  Gibson, 1969; “are the 2 letters same or different?”, subjects took longer to respond to P & R than to G & N Neural evidence  Hubel & Wiesel, 1962; microelectrodes in cat’s visual cortex; some neurons responded only to horizontal lines, others only to diagonals, etc. Recognition by Components (RBC)  Biederman, 1987; geons are building blocks for objects, like “letters” for seeing Recognition Process  parse complex objects into geons; find the edges; find the junctions between edges Biederman & Blickle (1985)  degraded figures—erased edges or junctions; 100 msec presentation rate; results were that 70% correctly identified figured with erased edges, while only 45% identified figures with erased junctions Criticisms of Existing Models Recognition…  is based strictly on the information contained in the stimulus; no role for context; also the perception of ambiguous stimuli (ex. 12 13 14 crossed with A “B” C) Context & Pattern Recognition Word-superiority effect  superior recognition of letters when they are part of a word than when they are alone, or part of a non-word; word context can be used to supplement information in the recognition of letters Example that context matters in object recognition  context information can be used to supplement feature information in the recognition of complex visual scenes Top-down processing  information from general context is used to help recognize a stimulus; high-level general knowledge contributes to the interpretation of the low-level perceptual units; suggests that context matters in pattern recognition; also known as conceptually-driven processing Bottom-up processing  information from the physical stimulus is used to help recognize a stimulus; start with small bits of info and combine them to form your perception; stimulus-bound interpretation; aka data-driven processing (i.e. based on information contained only in the data = stimulus) Psychologists believe…  BOTH types of processing are necessary to explain pattern recognition Holistic Face Processing  Farah (1994) suggested that: we process faces holistically (processing the overall structure of a face, paying little attention to the details); we process objects in a more detailed fashion Inverted Face Processing  it is harder to recognize the overall structure of a face when its converted compared to an object; any difÏculty recognizing inverted objects quickly disappears with practice (not true for faces!); Thatcher Illusion (Thompson, 1980) Factors Influencing Face Memory Patterson & Baddeley (1977)  categorized faces based on physical features (chin, nose, eyes, hair type), psychological features (honesty, intelligence, liveliness) Task  recognize the studied faces from unstudied faces Results  Participants were better at recognizing faces they earlier categorized on psychological dimensions rather than by physical features Prosopragnosia  inability to recognize faces despite good basic vision/intelligence; commonly known as “face blindness”; usually results from damage to the fusiform face area of the brain; a patient can recognize a face by the person’s voice or by a distinctive feature such as a mole or bright red hair color Remembering Faces  Bruce et al (1999) asked participants to find a match to the target face from an array of other faces or to indicate if the face was not in the array; results—only 65% accurate when the correct face was present, 35% of participants still picked a face even when the correct face wasn’t present Chapter 3: Attention Information overload  we are bombarded with more information than we can handle What Factors Determine What We Attend To? Goal-directed factors  endogenous control; intentional; direct your attention over the picture to find the object being described Stimulus-driven factors  exogenous control; incidental; salient, large objects that immediately grab your attention first Two Types of Attention Processes Selective Attention  picking stimuli for further processing; Cherry (1953); dichotic listening (shadowing speech in both ears) shows that we can ignore some stimuli; semantics—seek meaning or connection with listening Perceptual Selection  decide what to attend to and what to ignore; posterior attention network (located in posterior parietal region in the brain) Inhibitory Selection  stop yourself from performing an automatic action; anterior attention network (pre-frontal, facial region) Change Blindness  when we focus on one thing, we may not notice that other things have changed in an environment (ex. Moonwalking bear video); Harvard desk attendant study (75% did not notice change of person); demonstrates selective attention Inhibitory Selection  when things fall we try and catch them (water bottle vs. cactus!); The Stroop Task—demonstrates unintended processing; stimuli involving colors of words of color; first two tasks are control tasks Automatic Responses  some things are so habitual we have a hard time stopping them (reading and understanding numbers); anterior attention network tries to overcome these habits when needed John Cohen, Schizophrenia, and Inhibition Pen  writing implement is dominant meaning, also a forced enclosure for livestock (rarer); Cohen asked schizophrenic patients and healthy undergrads to read a sentence and ask what the word refers to; then observed what was highly active in their minds Schizophrenic patients…  usually activate the dominant meaning regardless of the context (“writing implement”) Feature Integration Theory (Treisman) Stage 1: Distributed Attention  all parts of the scene processed at the same time; parallel processing, register features automatically; occurs without conscious control; allows for efÏcient feature searches Stage 2: Focused Attention  each item in the scene processed one at a time; serial processing; glues features together to make objects; requires conscious control; needed for conjunction searches Divided Attention  dual task methodology (“doing two things at once”) Attentional cost  “how much does task X slow down another task Y?”; slowing is the attentional cost If…  cost(x) + cost(y) < total resources (then you can do it; otherwise you perform tasks more poorly) Simulated Driving Studies Levy & coauthors  2006; braking in response to hearing a tone Strayer & colleagues  2003; hands-free cell phones, trafÏc, braking; inattentional blindness Wikman & colleagues  1998; experienced drivers vs. novices Neuropsychology of Attention Parietal lobes  posterior attention network; sustaining focused attention; shifting attention from one location to another to detect a relevant target (ex. Visual search tasks) Frontal lobes  anterior attention network; responsible for controlling and directing attention; inhibitory selection (ex. Stroop Task) Visual Hemi-neglect (HN)  aka “spatial neglect”; decreased ability to voluntarily direct attention to a half of the visual field; basic visual field abilities are intact; loss often occurs on the left side of the visual world as a result of the right parietal lobe damage (however, the right visual field can be affected too…if damage is in the left parietal lobe) Attention Deficit Disorder  3 to 7% of all elementary school age children in North America are affected; ADD is more prevalent in boys; approx. 600,000 in US are prescribed Ritalin per year; no one single reason for ADD; have difÏculty filtering unwanted info and executive control is impaired Lou et al (1984)  PET study of children with ADD; diminished blood flow in frontal lobes; Ritalin increased blood flow in these regions and improved concentration for 3-4 hours