PSYCH 256 Lesson Notes
PSYCH 256 Lesson Notes Psych 256
Popular in Introduction to Cognitive Psychology
Popular in Psychlogy
One Day of Notes
verified elite notetaker
This 35 page Bundle was uploaded by Julie Notetaker on Sunday May 22, 2016. The Bundle belongs to Psych 256 at Pennsylvania State University taught by Dr. Nathan George in Spring 2016. Since its upload, it has received 11 views. For similar materials see Introduction to Cognitive Psychology in Psychlogy at Pennsylvania State University.
Reviews for PSYCH 256 Lesson Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 05/22/16
Lesson 1 Cognitive psychology: the scientific study of the mind Involves neuroscience, perception, attention, memory, knowledge, imagery language, problem solving, and reasoning and decision making Mind: encompasses all aspects of our neurological experience o Mind uses “code” to manipulate information o Mind must represent information in order to use, store, and manipulate this information o The brain must take information from the environment (like visual or auditory) or from within our brain (thoughts and feelings) and transform the information into a format that the brain can use o Every function our brain performs depends on how the brain is representing information Cognitive psychology is interested with understanding how these systems work by examining how this information is represented History o Greeks (Socrates, Aristotle, Plato) wondered how we gained knowledge about the world Nativism: knowledge present at birth Empiricism: knowledge gained through experience with an environment o Renaissance Rene Descartes Dualism/ mind-body dichotomy: makes a distinction between the physical body and the nonmaterial mind John Locke Tabula rasa: we enter the world with a blank slate and only gain knowledge and abilities through our experiences with the worlth Formed basis for behaviorist approach of early 20 century o 1800s Ernst Weber and Gustav Fechner developed methods to examine the relationship between perceptual experiences and environmental stimuli o First cognitive study Dutch physiologist Franciscus Donders developed a study that attempted to measure the time it takes for a human to make a decision Part 1: Simple reaction time task: subjects respond by pushing a button as soon as they detect a light Part 2: Choice reaction time task: subjects were presented two lights, one on the left and one on the right. When left turned on they hit left button and vice versa. By subtracting the simple reaction time task from the choice reaction time task, he could estimate the time it took to make a decision o Wilhelm Wundt: started first laboratory in 1879 in Leipzig Germany One of the founders on modern psychology His method of introspection proved too subjective and was abandoned o William James: In US, wrote first textbook of psychology, Principles of Psychology, and taught first courses in psychology o Rise of behaviorism leads to hiatus from study of mental processes Attempted to bring the methodology of psychology closer to the realm of basic sciences, such as chemistry, biology, and physics Focused efforts on the relationship between the environment and behavior, rather than introspection John Watson: classical conditioning B. F. Skinner: Watson’s student, operant conditioning o Gestalt psychology Our perceptual experience depends on the entirety of our experience and not the individual parts that make up the experience Proposed many rules for how we group objects Never took off in US due to rise of behaviorism o Cognitive revolution In late 40s and early 50s, researchers realized that any explanation of human behavior and abilities must include an examination of how people mentally represent the world around them “Cognitive psychology” term coined in 1967 by Ulric Neisser During WWII, human factors engineering was a growing field to deal with the increased amount of technology that required fast training Psychologists worked to design equipment with the user in mind Discovered that humans were processors of information with limits on the amount of information we can process George Miller: authored psychology paper that looked at methods to study the capacity of processing capabilities Examined how many distinct things we can perceive without counting and the number of unrelated things that we can recall immediately (somewhere between 5-9 with an average of 7) Noam Chomsky: revolutionized field of linguistics Critic of B.F. Skinner and behaviorism Demonstrated that behaviorism cannot explain how language is used by humans o Looked at grammar mistakes children make (“I ranned”, “He goed”, “Look at the deers”) o Behaviorism required reinforcement to occur, but children aren’t reinforced for the mistakes o Proposed that our acquisition, understanding, and usage of language are related to the way the mind is constructed, particularly in the way we represent information Alan Turing 1950 wrote a paper that developed the metaphor between the mind and the computer Turing test: test to examine whether a machine has intelligence o Said if you could have a conversation with it and believe it to be human then it must have some kind of intelligence Same time as computer use was rising in universities Input into a computer is coded into binary code so that the hardware and software are able to use, manipulate, and store the information o When we perceive information from the environment, our sensory receptors must take energy from the environment (electromagnetic energy for light, sound waves for sound) and convert the energy into signals that the brain can use (action potentials) o The brain must also represent the information in a way that allows us to connect the information from the environment with information that we have experienced before (to allow us to identify objects and people) o The brain has to store information so we can retrieve it later, as well as manipulate the information so we can use it. Differences o Active verses passive processing Humans have the ability to learn great amounts of information. Computers are limited in the ways they can process information because everything must be programmed into a computer o Serial verses parallel processing (one step must be completed before another can be started) o Transformations that computers make are based on code written by developers. Humans are based on code but are able to interact with our environment in a more complex fashion Methods in cognition o The experiment: researchers manipulate one or more independent variables (sometimes referred to as conditions) and measures how this manipulation changes something in the environment (called the dependent variable) Very powerful method Very controlled In laboratory Allows strongest conclusion to be drawn Gustav Fechner created method of constant stimuli Good at measuring thresholds: the minimum amounts of energy required to detect a stimulus is present or to the minimum difference required to detect a difference between two stimuli o Naturalistic Observations: consist of an observer watching people interact with their environment in real life contexts Represent what is going on in the real world Can study in natural settings Researcher loses control over the environment, more difficult to isolate causes and events o Controlled Observations: allows researchers to establish more control over the observations Participants may be selected on the basis of some characteristics, different instructions may be provided to different participants Often still conducted in real world but the researcher tries to influence the process Allows researcher to draw stronger conclusions and test a certain hypothesis Amount of control is less than a traditional experiment in laboratory o Neural Underpinnings: cognitive neuroscience that focuses on the study of the brain and the neural underpinnings of our behavior Lesson 2 Camillo Golgi: Italian anatomist Took slices of brain tissue and stained them with silver nitrate, creating pictures that showed the basic structure of a neuron, including a large network of interconnected cells “Nerve net”: at the time, it was believed tat the cells connected directly to one another, providing a complex pathway for signals to travel Santiago Ramon y Cajal: Spanish physiologist Used staining techniques to study the interconnection of neurons Made drawings of cells in different parts of the brain and discovered that these cells were individual units (not directly connected) that formed the building blocks of the nervous system Neuron doctrine: individual cells transmit information throughout the nervous system Neuron: cells that are specialized for signal transmission (typically electrical activity) Types: o Sensory neuron o Bipolar cell in the retina o Motor neuron o Type of skin receptor Structure o Soma: cell body Contains many of the life sustaining mechanisms the cell needs to stay alive Works to integrate incoming information and provides a starting point for the initiation of a signal to be sent to other neurons o Dendrites: Branch out from the soma Collect incoming signals and transmit them toward the soma Often receive signals from other neurons (interneurons) but can also collect information from the environment (sensory neurons) o Axon Long tube extending from soma Path by which neurons communicate with each other (and other parts of the body) Axon terminals/ terminal branches: branches at the end of an axon Allow signals to be transmitted to other neurons or cells in the body (such as muscles or glands) Action potentials: signals that neurons use to communicate o Discovered in 20s o Electrical in nature and result from the passing of ions into and out of the neuron o When cell is at rest, there is a higher concentration of sodium ions Na+ outside the cell relative to the inside of the cell; there is a higher concentration of potassium ions K+ inside the cell relative to the outside The change in concentration of the two ions creates a concentration gradient (where Na+ will try to get into the cell, and K+ will try to leave by the process of diffusion) Without outside input, the inside of the cell is slightly negatively charged relative to the outside, called the resting potential Many cells are around -70 mV (millivolts), but voltage can vary by cell type and location within the brain Input into the dendrites cause the membrane of the neuron to become more permeable to certain ions, particularly Na+ If the input into the dendrites is strong enough, it can cause the membrane potential to rise to threshold (-65 mV for many cells) If the membrane potential reaches the threshold, the structure of ion channels in the membrane change, and Na+ rushes into the cell This change causes a spike in the membrane potential, called depolarization When the membrane potential reaches the maximum value (typically +40 mV) the Na+ ion channels close and the K+ channels open When this process occurs, K+ rushes out of the cell, and the membrane potential drops Repolarization: the drop in voltage across the membrane Refractory period: the drop in voltage undershoots the normal resting potential of the cell During rest there is a high concentration of Na+ on the outside and K+ on the inside, after the action potential the concentrations are reversed, with Na+ on inside and K+ on outside. In order for the cell to fire again, the cell must pump Na+ outside and K+ inside the cell Requires a lot of energy During the refractory period, the cell is not able to have another action potential o The action potential starts near the base of the axon (where the soma meets the axon) and is propagated down the length of the axon Can only travel in one direction toward the axon terminals and is prevented from propagating backward by the refractory period o All or none response o Once a cell crosses the threshold, there is an influx of Na+ ions followed by an out flux of K+ ions The intensity is the same for every action potential (or every action potential within a single neuron) Brain: Weighs about 3 lbs. (2% of the body weight of a 150 lb. person) Uses 25% of the oxygen we breathe Examination techniques o Electroencephalography EEG First noninvasive procedure Developed in Germany by Hans Berger 1924 First EEG laboratory opened in US 1936 Measures electrical activity across the scalp, measuring patterns of action potentials Electrodes are placed on the scalp, electrical activity generated by neurons throughout the brain reaches the electrodes, and recordings show the changes in electrical activity at each electrode over time Great temporal resolution: the ability to see things change over time (1/1,000 of a second) Poor Spatial resolution: the ability to see things in a small area, like camera resolution Difficult to localize structures responsible for creating the neural activity, particularly if located far from the scalp o Event-Related Potential ERP Measures brain activity from the time before a stimulus is presented and for a period of time after Great temporal resolution Poor spatial resolution o Positron Emission Tomography PET Inject a radioactive substance into an individual and then use a device outside the head to measure radioactive activity given off from the substance Make a map of the brain based on changes in the flow of blood Relies on assumption that areas of the brain that are active will require more blood By placing a radio active substance directly into the blood stream, we can examine the areas of the brain that are using larger amounts of blood during a task One of the first methods that allowed scientist to look inside the brain of a living person Limited number of times you can complete the procedure due to danger of radioactivity Equipment is expensive because of radioactivity so must be carefully stored Each radioactive substance has a half-life so the scans must be completed quickly, typically within a few minutes of the injections o Magnetic Resonance Imaging MRI Creates a detailed map of the brain that recreates the structure and neuroanatomy of the brain down to the details s small as a mm and smaller Measure how atoms in the brain align themselves in predictable ways when placed in a magnetic field Similar to an X-ray but MRI allows us to see differences in soft tissue as well Functional MRI Uses same equipment but rather than taking a static image, an fMRI looks at areas of the brain that are using different amounts of blood Able to detect differences in concentrations of oxygenated verses deoxygenated blood in the brain o Single Cell Recording Recording the activity in a neuron using microelectrodes, which measure changes in electrical potential over time The electrical signals are very small and typically amplified and visualized on an oscilloscope Excellent spatial and temporal resolution (millisecond level) Very invasive Use in humans is limited, but have been used on many animals Used in humans to control epilepsy and develop brain machine interfaces Output is typically shown as the number of firings over time as indicated by the number of lines shown o Transcranial Magnetic Stimulation TMS Works by placing a magnetic coil close to a person’s scalp When turned on, it can excite or inhibit a particular area of the brain Similar to brain lesioning except there is no permanent damage caused by the procedure Useful for examining the functioning and interconnections of the brain Will only work on areas of the brain that are near the scalp Hindbrain and Midbrain o Provide support for basic survival functions such as respiration, blood pressure, coughing, sneezing, vomiting, and heart rate o Structures within these areas facilitate information transfer from the body to other areas of the brain o Cerebellum: “little brain” Located in back of brain, behind the spinal cord and underneath the occipital lobe Involved in coordination of muscle movements (does not initiate movement but it coordinates the movements and helps with balance) Damage results in irregular and jerky movements, tremors, and balance impairment Involved with our ability to shift attention between visual and auditory stimuli as well as motor learning Forebrain o One of the last areas of the brain to develop (both in evolutionary terms and in terms of prenatal development) o Thalamus: directs incoming sensory information to areas of the cortex o Hippocampus: processing and storage of certain types of memories o Amygdala: processing certain emotions and emotional memories o Cerebral cortex Consist of around 6 layers of neurons (about 3mm thick) that covers the brain Folds over itself many times, giving the brain the structure that you see in images Folds are not random, they are divided into areas based on the location of particular folds Occipital lobe Located in back of brain Is the primary receiving area for vision, the first area that processes visual information in the cerebral cortex Neurons in the visual cortex receive information from the eyes and start the process of building a representation of the visual environment Organized in structured layers of cells and represents information in a map like way to correspond with the environment (objects that are close to each other in the environment are processed as being close to each other in the brain) Temporal lobes Located just in front of the occipital lobe near the ears Primary receiving area for audition but also important in object identification and recognition of faces Located near hippocampus and damage can result in memory deficits Parietal lobe Located in front of occipital lobe and above the temporal lobe Somatosensory cortex: primary receiving area for sensory information: touch, temperature, and pain Involved in directing attention and representing visual information in a spatial map Frontal lobes Located at front of brain, broken into three separate regions Motor cortex: o Located at back of frontal lobe and just in front of the parietal lobe o Directs voluntary movements and fine motor control Premotor cortex o Involved with planning these movements Prefrontal cortex o Executive functioning: planning, making decisions, creating and using strategies, inhibiting inappropriate behaviors, among others Distributed processing (Neural code): specific functions are processed throughout many different areas of the brain o While certain functions are localized to parts of the brain, our perception is the integration of many different functions o One challenge of perceiving our world is taking the distinct aspects of perception and bringing them together into a single conscious experience o Another challenge the brain faces is how to code for different aspects of our perceptual experiences We know the difference between an office building and apt, dog house vs. human house Evidence from lesion and fMRI studies suggest that buildings are processed in an area of the temporal lobe called the parahippocampal place area PPA in the parahippocampal gyrus Specificity coding/ Grandmother Cell Hypothesis: a single neuron coding for a single stimulus or object Would require a large amount of cells to encode for every object and person we know When we look at cells in the object recognition areas, cells tend to respond to more than one stimulus If we coded each object with a single cell, we would expect cases where damage to the brain would result in our inability to recognize a single object Distributed coding: distributing the coding across multiple cells Allows for smaller numbers of neurons to represent a large number of objects Our perceptual experiences include not only our specific representation of the object but also include many other aspects such as specific memories and emotional experiences Lesson 3 Perceptual experience: taking information from the environment, converting this information into signals our brain can use (action potentials), and using these action potentials to build a representation of our environment Perception: recognition, organization, and interpretation of information from our sensory experiences Each of our senses has receptors that detect a particular type of energy in the environment that they convert into action potentials that are sent up to our brains o Vision: receptors in our eyes detect part of the electromagnetic spectrum Light: the part of the electromagnetic spectrum that we can detect Colors are associated with wavelengths from around 400-700 nm o Hearing: receptors in our ears detect sound waves of a particular frequency o Taste: detectors on our tongues detect various chemicals in food and drink Bottom up processing: processing that starts with information from the environment, its conversion into action potentials, and the transmission of these signals toward the brain o Transduction: converting energy into action potentials Retina: layer of tissue in the back of the eye Rods and cones contain pigments that break apart when light of a particular wavelength strikes them When the photo pigment breaks apart, it causes a change in the membrane potential of the rods and cones, which leads to an action potential, starting the process of sensation There is a precise pathway that the action potential travels as it leaves the sensory receptors in the eye and travels to the brain Ganglion cells: have long axons that carry action potentials out of the eye and toward the brain Top down processing: using our past experiences to guide and interpret the information that is coming in through our senses o ABC or 12 13 14, if B and 13 look the same, we will read it correctly because of top down processing and our knowledge of how letters and numbers go together Gestalt Grouping Principles o Proximity: we group things together that are close to each other o Similarity: we group things together that are similar to each other in some characteristic, such as shape or color o Good continuation: we group together objects whose contours from a continuous straight or curved line o Connectedness: objects or parts of objects that are connected tend to be grouped together o Common fate: we group objects based on movement, objects that move together tend to be grouped together o Pragnanz: of all possible ways to interpret our environment, we tend to perceive the pattern in as simple of a way as possible. Thus we have a tendency to look for simple and symmetric forms in our environment o The laws compete with each other and are not always absolute, they are our best guesses about the environment o We see optical illusions because something about the illusion violates the heuristics our brains use to build a representation of the world around us Regularities in the environment o Light comes from above Shadows can be used to convey depth, motion Two processing streams o Our movements can influence our perceptions and our perceptions influence our movements o “What stream”: One processing stream is involved with perceiving objects and characteristics about them o “Where/how stream”: The other stream is involved with locating and making actions toward or with these objects o The two streams run along the ventral (bottom) and dorsal (top) areas of the brain o Streams discovered by physiologists studying the effect that damage to a particular brain area had on perceptual experience Ungerleider and Mishkin 1983 trained monkeys on two types of tasks, one required the animal to recognize an object based on previous experience (object discrimination task), the other task required the animal to choose the location that was closest to a tall cylinder (landmark discrimination task) If the animals chose correctly they were rewarded with food After demonstrating high performance rates, the researchers damaged parts of their brains to determine the effect on performance When the temporal lobe (ventral stream) was damaged, the animals showed difficulty with the object discrimination task When the parietal lobe (dorsal stream), the animals showed difficulty with the landmark discrimination task o Milner and Goodale 1995 found individuals with damage to the ventral stream who had difficulty recognizing objects but no problems with localizing or performing actions on them Patient D.F. suffered damage to her temporal lobe due to a gas leak that released carbon monoxide in her home Perceptual orientation matching task o She was required to look at the angle of a slot and determine the orientation of the slot o The second task she was required to place a card in the slot o She was unable to determine the orientation of the slot but she could easily place a card in the slot Lesson 4 William James: 1890/1950 one of the founders of modern psychology Said attention “is the taking possession by the mind in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. It implies withdrawal from some things in order to deal effectively with others.” Attention: a filter that allows some information to pass onto higher levels of processing n Three classes of filter models: early, intermediate, late selection n Bottleneck theories: restricting information processing, preventing all information from passing through n Early n Broadbent: proposed the most famous of early selection models n The attended message is filtered based on physical characteristics contained within the message (pitch, rate, gender) n Information that is attended passes through the filter and is able to reach the next stage of processing n The detector processes all information that passes through the filter to determine higher level characteristics n Dichotic listening task: participants listen to two messages, one in each ear. They were asked to follow one of the messages and ignore the other n Subjects had no problem completing the task n Supported Broadbent’s model because subjects would filter out the unattended message based on the location the information was received n When they were asked about the unattended ear, they could report very little n Cocktail party effect: n Not explained by the early selection theory because they predicted we would filter out any unattended information` n Researchers have discovered that if the message in the attended ear suddenly switches to the unattended ear, participants will follow the switch without realizing it n Intermediate n Treisman created the Attenuation theory n All incoming information is processed to some extent, with the unattended information diminished n Analyzing physical properties, such as loudness, pitch, speed n Parsing information in linguistic terms by processing the message into syllables and words n Processing the message on a deeper, sematic level n All information reaches the attenuator. Based on the physical characteristics and basic meaning of the message, the attended message is allowed to pass. Everything else is turned down in the background before all of the information is passed on to higher levels of processing n Late n All information is processed to a deeper level and messages are selected for attention based solely on meaning n Studies show that semantic meaning of information presented in the unattended channel can bias our interpretation of information in the attended channel, even if participants were not aware of the biasing information in the unattended channel n Early and late selection are present in certain situations, depending on the task participants are completing n Visual attention n Covert: occur without corresponding eye movements n Precueing: a cue is presented in a location where a stimulus is likely to occur n Location based attention n Information at the location where attention is directed is processed more efficiently and quickly than information that is not at the location of attentional deployment n Posner referred to this as a spot light n Suggest that attention must physically move around our visual environment from one point to another n Studies show that we have some control over the size of the spotlight, like a zoom on a lens n Object based attention n Egly, Driver, and Rafal used a precueing procedure that compared predictions from location based and object based attention n They designed the stimuli to appear to be two vertical rectangular boxes behind a horizontal rectangle n They cued one of the ends of one of the two rectangles, a target then appeared at one of the ends of one of the two rectangles n The stimuli were designed for the spatial distance between locations 1 and 2 was exactly the same between 1 and 3, creating same object invalid cues and different object invalid cues n They found that when the target appeared on the same object as the cue, reaction was faster than when target appeared on different object n Neisser and Becklen 1975 showed subjects two movies that were superimposed on each other n Participants were asked to report on characteristics of one of the movies n Subjects could only follow one movie at a time n If a scene is relatively static, we may move attention around to regions of space like a spotlight. In dynamic environments, we may use object based attention to fixate on specific objects as they or we move about the scene n Location and object based attention may activate different areas of the brain n Overt: attention shifts accompanied by eye movement n Bottom Up processing n Stimulus salience: factors such as color, contrast, and movement that determine where attention may be allocated n A light turning on that we immediately pay attention to n Top down processing n Attending to aspects of the scene based on our interpretation and understanding of the scene itself based on top down processes n Texting while driving uses up processing power that should be used on driving n Strayer and Johnston studied participants while they used a cell phone while driving n Participants were much more likely to miss the light and slower to press the break in response to the light n Wilson and Stimpson showed that as cell phone usage has increased in the past few years, traffic fatalities due to distracted driving have increased greatly n Feature integration theory: theory by Treisman that we perceive objects in two distinct stages n Preattentive stage/ automatic stage: we process basic features of the object, such as color or form n Second stage: attention glues these features together so we perceive a single object n Illusory conjunctions: the combination of features from different stimuli n Treisman and Schmidt did experiment where they had participants report the two numbers on either side of a display, which they were right 97% of the time, and to indicate the letters, their position, and their color, which they were right 39% of the time n Physiological underpinnings n Attentional processing is distributed across a large number of brain areas (more than 32) n Individuals with damage to the parietal lobe have problems directing attention to objects and places on their left. They behave as if that part of the world were not there n They would draw a picture without the left side, eat only one side of a plate, wash only one side of face, or brush only half of teeth n Attentional processing enhances neural firing of attended stimuli n In the Colby study, monkeys were trained to look at a fixation point and either attend to the fixation point or attend to a location where a peripheral light would appear n Researchers used a singlecell recording technique to record the firing rate of a single neuron in parietal cortex n The neuron produced limited response when attention was directed at a fixation point, and the light appeared in the periphery. However, when the monkeys directed attention toward the peripheral light, the same neuron increased firing rate n Since the light falling on the retina was the same in both conditions, the difference in firing rate of the neuron must be due to differences in attentional allocation n Showed that attentional processes can modulate the firing rate of individual neurons Lesson 5 Memory: The power or process of reproducing or recalling what has been learned and retained especially through associative mechanisms The store of things learned and retained from an organism’s activity or experience as evidenced by modification of structure or behavior or by recall and recognition Processes involved in retaining, retrieving, and using information about stimuli, images, events, ideas, and skills after the original information is no longer present Cognitive process involved with the storage, retention, and retrieval o information History o Plato compared memory to a wax tablet on which impressions can be made o Middle ages, analogies were made between memory and a cave and memory as an empty cabinet Modal Model/ Atkinson-Shiffrin model Memories pass between three different memory systems. Sensory memory: holds unattended information for a very short period of time (.5-5 seconds) Short term memory: holds a few number of items, 3-7 for a short period of time (15-30 seconds) o With rehearsal things can be kept in memory longer Long term memory: limitless and information can last for years Assumes that memory is an active process, and the three modes continually interact Information must go through sensory memory to get to STM, and STM allows us to use our knowledge from LTM in the present context we are in The memories stored in each mode are representations of information; they are coded by firing patterns across neurons in particular areas of the brain Sensory memory Iconic memory: visual sensory memory o Sterling would show participants letters for a brief duration and would asked them to record what letters they saw. He found that they could recall 4-5 of the 12 letters in the whole report task Participants recorded having seen all the letters at one point but then they faded from memory while they tried to recall them Partial report method, they only had to recall letters from a particular row that was indicated by a tone, in this trial they performed at 80% In the delayed partial trial, the longer the time between the stimulus and the cue, the worse memory performance He concluded that sensory store holds most of the incoming sensory information but only for a limited duration Echoic memory: auditory sensory memory o Dichotic listening task: participants would listen to four channels of random letters. In whole report method they were asked to recall the letters in all streams. In partial, one of the channels was cued. They found that participants could report more in the partial task o They found that auditory sensory information lasts about 5 seconds o Echoic may have larger capacity than iconic Short-term memory George Miller discovered 7 +/- 2 as the capacity of STM o Memory span task giving participants a random string of digits and asked them to recall them in order, if they got it correct, he would add a number. The last length they could reach was their digit span Chunking makes it possible to increase capacity Researchers gave a group of three letters to be remembered and then made participants count backwards for a few seconds and then asked the to recall the letters o Found that memories were gone by 18 seconds as long as rehearsal was prevented o Average duration of 15-30 seconds Working memory: limited capacity temporary storage system that underpins complex cognitive thought New model proposed by Alan Baddely to deal with the fact that STM did more than store information Involved in storing information for a short period of time, but also involved in reasoning and comprehending language Brooks demonstrated that we have two distinct systems, one for verbal information and another for visual and spatial information o Spatial mental imagery task: participants told to visualize a letter. The task was to start at the upper corner of the letter and move around to each corner and indicate whether the corner was an inside corner or an outside corner o Sentence task: participants were presented with a sentence and they had to classify each word in the sentence on whether it was a noun (dotted underline) or not (solid underline). o They either made their responses out loud or spatially o Found that performance was best when the task and response were in two different modalities If they completed the sentence task, they were quicker when they made the spatial response, and the opposite for the mental image task There is a limited capacity resource the task and response are competing for, if the task are in different modalities, it reduces the competition Central executive: director of the flow of information, acting as the control center of the system o More of an attentional system than a separate memory store, choosing which information will be operated on by which component o Coordinates current environmental information with information stored in long term memory o May be located in frontal lobe as people with frontal lobe damage have problems controlling attention and shifting between tasks and strategies Phonological loop: processes and stores auditory information o Phonological store: limited capacity and hold information for a few seconds o Articulatory rehearsal process: rehearses items and can keep information in the phonological store from decaying o Word length effect: our memory is better for lists of short words than for long words People can remember the number of items they can pronounce in 1.5-2 seconds When examining digit spans in different countries, they found correlating evidence for the length of words in the language o Phonological similarity effect: we confuse items in STM that sound similar to each other Episodic buffer: serves as temporary storage system that interacts with both the phonological loop and the visuospatial sketchpad o Proposed because the properties of the phonological loop and visuospatial sketchpad seem to have too little storage capacity to explain many of the phenomena associated with working memory Many sentences we hear or read are 20-30 words long, beyond typical capacity for working memory We use working memory to follow along with a story or movie, episodic buffer proposed to be involved with chronological ordering of information Visuospatial sketchpad: responsible for representing and storing visual and spatial information o Involved in planning complex spatial movements o Visual imagery At least 60 areas of the brain have to do with working memory o Prefrontal cortex Damage to the prefrontal cortex results in difficulty with functions that the central executive is proposed to perform, particularly with problems controlling attention and switching tasks or goals Studies using transcranial magnetic stimulation TMS have shown that disruption of neural circuits in prefrontal cortex causes participants to have difficulty with working memory tasks Funahashi used single cell recording to examine neurons in the prefrontal cortex while a monkey was carrying out a delayed response task Monkeys were trained to look at X on a screen, after a period of time a square would appear somewhere in the display. After a delay, the X would disappear and the monkey was trained to move his eyes to were the square appeared A cell in the prefrontal cortex made a small response when the square appeared, and then a larger response after the square disappeared and the monkey was holding the location in memory. When the monkey made an eye movement toward the location, the firing dropped dramatically Lesson 6 Sensory Memory: copy encoding/ large capacity/ 0.55 seconds Working memory: acoustic/visual encoding/ 7 +/ 2 / 20 seconds Long term memory: semantic encoding/ very large capacity/ years l Our LTM helps with our understanding of what is currently happening because we can use our experiences and knowledge about the world to interpret what is happening around us Serial position effect: l Murdock found that people tend to recall the items at the beginning and end of a list but don’t remember nearly as many items from the middle of the list l The resulting curve is the serial position curve l Primacy effect: increase in memory for the first items on a list l When the first word is presented, we start to rehearse it; we rehearse the second and so on until our STM is at capacity. During rehearsal, we transfer some information to LTM l Recency effect: increase in memory for the items at the end of a list l We recall these items from STM l Researchers have delayed recall for 30 seconds by having participants work on a second task. Delaying recall reduced the recency effect but not the primacy effect l Patients with forms of amnesia that prevent the formation of new LTM show no primacy effect but will demonstrate a recency effect Coding in LTM l Primary coding is sematic l Baddeley presented lists of words that sounded similar or lists of words that were similar in meaning. After presentation, participants performed a secondary task for 20 minutes to prevent rehearsal of the items and to ensure they were using LTM l He found that semantically similar lists were more susceptible to errors than acoustically similar lists l Sachs had participants listen to a passage of text and after they were presented with a set of sentences and they had to identify whether the sentences were exactly the same or whether they had been changed l She found that if the sentence task was presented immediately after the presenting of the passage, subjects were able to correctly identify the wording of the sentence. As the delay between the sentence task and the hearing increased, participants had a harder time identifying the exact wording of the sentence but had few problems identifying the meaning STM and LTM brain differences l Studies have reported a double dissociation between STM and LTM in the brain l H. M. had his hippocampus removed on both sides of his brain in an effort to control epileptic seizures, and because of this he could no longer form new LTM l Clive Wearing had memory deficits from a viral infection and can no longer make new memories, the only person he remembers is his wife l Shallace and Warrington described patient K.F. with severe deficits to STM but an intact LTM. They had a digit span of 2 yet she could form new LTM about events that occurred in here life Different types of LTM l Explicit memories/ declarative memories: conscious memories that include memories for facts and knowledge that we have about the world l Episodic memories: memories for events in which you participated l Tulving said episodic memories are stored in a temporal way. Events are recorded as having occurred before, after, or during the same time as another event l He said that the distinction between episodic and semantic memories rests on mental time travel (travelling back in time mentally to recall events that happened in the past) l What distinguishes an episodic memory from a semantic memory is whether we can recall the exact time that we encoded the memory l Semantic memories: facts and knowledge that we have about the world l We don’t travel back in time, we are retrieving things we are familiar with l Information is organized on the basis of meaning and relationships between pieces of information l Schacter reported case studies of individuals with different kinds of amnesia that provided evidence for the distinction between episodic and semantic memories l Patient Gene suffered damage to his frontal and temporal lobes in a motorcycle accident when he was 30 l Anterograde amnesia: inability to form new LTM l Retrograde amnesia: inability to recall previous things that have happened l His amnesia was related to episodic memories. He couldn’t recall any birthday parties, conversations, first days of school. But he did recall facts about his life, like where he went to school, where he worked, and some of his coworkers l Those memories represented knowledge Gene had about the world, thus semantic memory rather than episodic l A woman from Italy suffered from viral encephalitis that impaired her memory abilities. She had difficulty recognizing familiar individuals, she didn’t understand the meaning of familiar words, and she had difficulty recalling facts and knowledge from history that she knew before her sickness l She showed damaged semantic memory but intact episodic memory, she could remember events in her life, what she had done earlier in the day, or weeks earlier l Studies have shown different activation areas for semantic and episodic memories l Our episodic memories must get transformed into semantic memories l Implicit memories/ nondeclaratve memories: memories that we are not consciously aware of but show evidence of prior learning or storage l Procedural/ skill memory: typically involve some kind of action like riding a bike, tying our shoes l Mirror drawing: get a small mirror and sheet of paper with a star on it. The task is to try to trace the star by only looking at the reflection of your hand in the mirror l H.M. practiced the task over 3 days. Everyday he would indicate that he had never completed it before but he showed improvement over the 3 days l Patients often have difficulty encoding new explicit memories but can encode new implicit memories l Priming: when exposure to one stimulus changes a response to later stimuli l Repetition priming: when cognitive processing of information is facilitated by previous exposure to the same information l Word Stem completion task: participants are briefly exposed to a word such as Tree and then shortly after are given a word stem completion task like “fill in the blanks tr_ _ _”. Priming is seen when there is an increase in the probability of completing the stem with tree relative to those people who did not see tree earlier l Warrington and Weiskrantz studied a group of four amnesic patients and compared them with 8 control subjects without damage to the brain l Two of the tasks were explicit memory: free recall and recognition task l Two of the tasks were implicit memory: word stem completion, and word fragment task l Word fragment task: subjects were given a list of words, sometimes they were told they would be used in a later test, sometimes they were not. After presentation of the words they are shown a word that has been fragmented. The task was to identify the word. Priming was demonstrated when participants used on of the words previously presented l Amnesia patients performed significantly worse on the explicit tests of memory but performed at the same level for implicit tasks l Conditioning Lesson 8 Encoding l When we are processing information in STM, we can process the information in one of two ways l Maintenance rehearsal: trying to memorize something by repeating it over and over l Works well for keeping memory active in STM but doesn’t work well for transferring it into LTM l Elaborative rehearsal: when you relate the information in STM to information you already have stored in LTM l Nickerson and Adams asked participants to pick out a picture of a real penny from a group of fake pennies. Only 4 out of 25 picked the real penny l Indicates a failure of encoding because we didn’t encode the material when we were exposed to it Levels of Processing Theory LOP: memory strength depends on how the information was encoded. Deeper processing leads to better memory l Developed by Craik and Lockhart l Participants were given lists of words and had to answer one of three types of questions about each word l Incidental learning: they were never told that they would be tested on memory l One question asked about capitalization (physical processing) l One question asked about rhyming (acoustic processing) l One asked if the word fit in a sentence (semantic processing) l After answering the questions they were given a surprise recognition tests for the words l Results showed that semantic processing lead to better memory l Imaging studies have shown differing activation levels in the frontal lobe for information that is processed at deep verses shallow levels, suggesting that the amount of processing in the brain might be related to the strength of the memory l Baddely said that the LOP approach is limited without a precise definition of what constitutes deep processing l Visual imagery l Bower and Winzenz presented pairs of words to participants and had them repeat the words (repetition condition), use the two words in a sentence (sentence generation condition), or create a mental image of the words (imagery condition) l The best memory came from those instructed to create a mental image of the words l Self reference effect: when we relate things we want to remember to ourselves, it can lead to stronger memories l Generation effect: we are more likely to remember items that we generate ourselves rather than simply read l Testing effect: we are more likely to recall information that has been repeatedly tested over rather than repeatedly studied Retrieval: bringing our memories out of the memory store into a representation that we can use l Many memory failures are to do with the retrieval process. The information is stored, but not in a way that allows easy access l Retrieval cues: words, stimuli, places, feelings, anything that is related to a memory and needed to access that memory l Cued recall: Instead of providing lists of words to remember, cues are provided to help jog the participants memory l Tulving and Pearlstone gave subjects lists of words to remember and then broke the subjects into two groups. One group was simply told to recall the words, the other group was given the categories the words came from l The group given cues remembered almost twice as many words as the group without cues l Encoding specificity: information we want to remember is encoded in our memories along with the context in which we are exposed to information l Godden and Baddeley had subjects learn a list of words while they were on land or under water. Later their either recalled the words on land or in water l Results show that memory was best when the contexts matched l Memory is better when our internal state is similar during encoding and retrieval l Goodwin had participants study word association lists either sober or after drinking. The next day they recalled the words in either a sober or intoxicated state l Best performances were when participants were sober, but when the participants were intoxicated, they were better off being intoxicated at the test l Goes against LOP because in the right situation, deeper processing can lead to worse memory l Morris, Bransford, and Franks had participants complete one of two tasks (standard LOP sentence task and rhyming task) during the encoding process and had them take one of two types of tests (standard free recall or a rhyming recognition test) l Found that deeper processing didn’t always lead to better memory l With a standard recall test, participants performed better when they completed the sentence task (semantic). But with a rhyming recognition task, they performed better when the encoding task was a rhyming task Memory and the Brain l When we experience something, our brains represent the experiences through action potentials in various area of the brain. In order to remember something, we need to encode something about the representation l Changes at the synapse l Hebb proposed that when a particular experience causes a neuron to fire, the synapses between itself and other cells are strengthened, either through greater neurotransmitter release or changes in the number of receptors on the receiving neurons l Long term potentiation: the strengthening of signals travelling across a synapse l When neuro
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'