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This 30 page Class Notes was uploaded by Gabriela Saint-Louis on Tuesday September 22, 2015. The Class Notes belongs to PSYC 3121 at George Washington University taught by Myeong-Ho Sohn in Fall 2015. Since its upload, it has received 48 views. For similar materials see Memory and Cognition in Psychlogy at George Washington University.
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Date Created: 09/22/15
092215 Exam Tuesday 30 mc 10 from each chapter 3 short answer 1 from each chapter Visual Search Conjunction search looking for a target that is different from the distractors by not just one but a conjunction of features shape and color Slope re ects amount of time it takes to exampne conjunction features in a search Requires serial examination if we don t have time to combine featurs in one object all we have left are a bunch of features and not a solid representation of object it can fail because it requires time so if you don t invest time and energy this search will not be successful Feature Search Binding visual object identification spatial or temporal conjunction of features feature of processing when we only have one difference not much work what becomes part of your consciousness it must have required prior effort to establish a recognition Illusory Conjunction 0 individual features are processed before location preattentively does not require cognitive researching I to combine features you need to have a reference point I there may be some linearity in visual processing feature location perception I if all you have is features you don t have a good sense of location but if you ve already completed the conjunctions earch you would need to know where the conjunction happened target location vs featue search does not require location 0 then conjoined to form an object attentive process 0 features re independent of locations 0 need more than 2030 ms 0 3 objects you have an idea that you saw three things but not sure hich feature is going with another to form an object if early visual processing is disturbed they report illusory objects say things were there that weren t report digits and objects seen in ashing of image for 2030 ms feature processing is good does not require cognitive research but the binding of features may not be complete people will have accurate idea of the feature 0 When attending to an object Luck et al 1997 macaque 0 neurons in macaque brain that are responding to the bue vertical regardless of if it is presented alone or with something else 0 The gorilla video the fact that we can focus on white shirts means we have a mechanism in brain for binding binding is a mechanism is a mechanism that signlas out task relevant information 0 you know something black is going around but identifying it would require cognitive researching which you don t have time 0 supports early selection if selection occurs early in the visual processing and binding is successful if binding process is successful then you will not be aware of semantic information in unintended channel if binding occurs after semantic information then it would be late selection Kastner et al Human Simons amp chabirs 0 Visual Neglect does binding take place just on location or something else so far we assume it is location Posner Cohen 0 damage to right parietal region 0 asymmetry in attention shift in a static display location is confounded with objects how do people go back between location and object based selection location stays still but objects can move around generally we are equipped with both selection mechanisms object and location based I visual neglect inability to pay attention to a contralateral side of the visual field most studies have been done with patients ith damatge to left parietal cortex ques presented to left vs right and where the target really was que wills stay in place until you realize you need to divert attention to target location in study graph as long as target is presented in right when quee is on right but target is on left you have to disengage attention to the left this person s left hemisphere has to disengage information from right side to left whenthe right cortex has to disengage from right side to the left there is a difficulty damage in right side and cue is presented on right hand side left cortex is engaging and claiming attention on the right hand side left cortex is healthy but then a target appears on left side if it is healthy right cortex will disengage and move to left if right is too weak it will be harder and take longer 0 Unilateral Visual Neglect 0 dmage to right parietal region 0 ignoring the left visual field 0 image patient asked to check off all the circles they see person with visual neglect will only cross off circles on right hand side and ignore the ones on the left side 0 not trouble with visual system they see all the circles but the roblem is the attention applying feature to location 0 example Clock ask people with right parietal cortex tdamage to copy it they will only draw the right side as though left side does not exist 0 Hemispheric asymmetry 0 left parietal local spatial attention 0 Right parietal global spatial attention 0 image one copy has original and other columns show copies done by patients with left and right parietal cortex damage middle colomn has component parts but not the overall shape global spatial attentionRight parietal cortex damage right column has the shape but not the components local informationleft parietal cortex damage when we analyze objects division of labor one focuses on global location and another part analyzes local spatial features 0 Object based attention I same object benefit 0 withinobject comparison is betwteen than betweenobject comparison 0 object than location may be basis of attention 0 if space based attention is the only slection mechanism the distance will be the driving force 0 late selection information is available to you and you select the best semantic meaning 0intraindividual distance head to toe which is one object may be further than intervidual distance head to head which deals with two objects 0 distance between two points may play minor role but distance between stimulus is more important 0 task compare to see if oj ects have same number of bumps whether the bumps belong to the sme object examining distance beteen both sets of bumps People respond faster if bumps belong to same object even though it enforces longer distance examining space and location is ignored or donplayed here 0 professor holding bag space based attention scnning his head and bagwobj ect based examining bag and then his head 0 people respond faster to qued location than unqued location target presentation 0 time sensitive 0 Inhibition of return people respond faster to objects in unqued location 0 moving attention to netural position if object appears in qued location as you re moving attention away to go to netural it takes longer to go back if it appears in unqued location it is faster because your attention was already headed there 0 spacebased attention 0 qued object vs qued location whether inhibition of return occurs on basis of space or object I inhibition of return can occur on both 0 Central Attention IThinking which line of thinking are we going to maintainone thinking at one time on a given input slection bottleneckl encoding slection motor I cenral attention refers to the selection process eX given problem 23 and he tosses marker but you have to suppress that to focus on problem to solve answer and produce it I three possibilities 1 perfect time sharing no resource limitation you can do multiple things at the same time 2 no time sharing at all you have to wait for completion of one task before you begin another 3 selection bottleneck you may be able to encode multiple stimuli and produce multiple responses at the same time if they respond different motor ex 1 response involves verbal and another requires manual response eX 23 and capital of France you may be able to register both questions at the same time but the selection part has to be done serially intergration of features September 1 2015 Chapter 1 Behavioral Information processing approach 0 Stormberg experiement 100 replicability I Gives us opportunity to exercise how to approach cognition I come up with causal and not just correlation to output and input patterns 0 class experiment 0 set size ordering subitizing the ability to count immediately type of probe 0 serial position effect ex number presented first and last more memorable would have to assume set is being viewed left to right the opposite would be parallel position effect info is being scanned at once Reaction timecomparison does not change for parallel search vs serial I selfterminating for targetl serial position shouldn t matter if they stop search I exhaustive 0 set size if people perform parallel search the reaction time would produce a at line equal reaction time I for serial search the more you have to consider the more time increasing line I as size increases reaction time increases 0 type of probe foil stimulus that should be responded negatively or target positive I regardless of set size must consider all items in set to say no for target I exhaustive search looking for foils must consider all items and higher slope whether it s yes or no you still keep going through the entire memory set slopes are same for yes and no if decision making is same then we can predict same slope I selfterminating search looking for target as soon as you reach the target you can end the search slope will not be as steep as in the no trials Yes trials on average has less number of comparisons comparison entails decisionmaking can skip rest of search and produceresult 0 two components of stimulants I Probe target F0i1n0t part of trial September 03 2015 Left hand vs right hand exercise left hemisphere controls right Right hemisphere controls the left left hand is controlled by right hemisphere reading controlled by left hemisphere left handed people language center varies show variety of subgroups right handed people language center is 99 percent in left hemisphere results should show more right handed performance Contralateral Control control laterality is the manner of control brain controls opposite side of the body and sends information to opposite side of the body 0 left hemisphere sends information for motor of right side of body etc 0 varies depending on domain I for visual domain control laterality is almost overlapping Neurons smallest unit that makes up the brain branches dendrites receive information travels through axons axon terminal will release neurotransmitters that will travel the gap between neurons synapse and willr each dendrites of post synaptic neuron 0 neurotransmitter transmission method is chemical 0 between neurons information transmission takes place chemically 0 within a neuron information transmitted through electric shock action potential I inside more negative inside neuron myelin sheath insulation to achieve faster speed Information Transmission always a gap between neurons called synapse dendrites of a post synaptic neuron has to have a receptor that matches what it is receiving Between Neurons 0 chemical 0 neurontransmitters 0 excitatory and nhibitor Brain Gross Anatomy Dopamine lower than normal level trouble in controlling movements memory vs applying physically the part of the brain responsible for remembering rules is different than art of the brain for executing the procedure Basal Ganglia Amnesic Brain Hippocampus and basal ganglia play key roles in human memory and learning Brain organization Localization 0 different parts of brain Within hempisphere being responsible for different things 0 Primary areas I motor cortex send motor commands I somatosensory receives information from different parts of body 0 interact with environment directly I Pre frontal cortex devoted to carry out high level cognitive behavior like reasoning language I Postrrior spatial attention Lateralization 0 different hemispheres Topography Aphasia localized in the left hemisphere Broca Apasia ability to produce speech Wemicke aphasia inability to form a coherent sentence 0 this area deals with meaning of wordsobj ects semantic understanding 0 damage here results in lack of semantic understanding September 03 2015 Left hand vs right hand exercise left hemisphere controls right Right hemisphere controls the left left hand is controlled by right hemisphere reading controlled by left hemisphere left handed people language center varies show variety of subgroups right handed people language center is 99 percent in left hemisphere results should show more right handed performance Contralateral Control control laterality is the manner of control brain controls opposite side of the body and sends information to opposite side of the body 0 left hemisphere sends information for motor of right side of body etc 0 varies depending on domain I for visual domain control laterality is almost overlapping Neurons smallest unit that makes up the brain branches dendrites receive information travels through axons axon terminal will release neurotransmitters that will travel the gap between neurons synapse and willr each dendrites of post synaptic neuron 0 neurotransmitter transmission method is chemical 0 between neurons information transmission takes place chemically 0 within a neuron information transmitted through electric shock action potential I inside more negative inside neuron myelin sheath insulation to achieve faster speed Information Transmission always a gap between neurons called synapse dendrites of a post synaptic neuron has to have a receptor that matches what it is receiving Between Neurons 0 chemical 0 neurontransmitters 0 excitatory and nhibitor Brain Gross Anatomy Dopamine lower than normal level trouble in controlling movements memory vs applying physically the part of the brain responsible for remembering rules is different than art of the brain for executing the procedure Basal Ganglia Amnesic Brain Hippocampus and basal ganglia play key roles in human memory and learning Brain organization Localization 0 different parts of brain Within hempisphere being responsible for different things 0 Primary areas I motor cortex send motor commands I somatosensory receives information from different parts of body 0 interact with environment directly I Pre frontal cortex devoted to carry out high level cognitive behavior like reasoning language I Postrrior spatial attention Lateralization 0 different hemispheres Topography Aphasia localized in the left hemisphere Broca Apasia ability to produce speech Wemicke aphasia inability to form a coherent sentence 0 this area deals with meaning of wordsobj ects semantic understanding 0 damage here results in lack of semantic understanding September 1 2015 Chapter 1 Behavioral Information processing approach 0 O O Stormberg experiement 100 replicability I Gives us opportunity to exercise how to approach cognition I come up with causal and not just correlation to output and input patterns class experiment set size ordering subitizing the ability to count immediately type of probe serial position effect ex number presented first and last more memorable would have to assume set is being viewed left to right the opposite would be parallel position effect info is being scanned at once Reaction timecomparison does not change for parallel search vs serial I selfterminating for targetl serial position shouldn t matter if they stop search I exhaustive set size if people perform parallel search the reaction time would produce a at line equal reaction time I for serial search the more you have to consider the more time increasing line I as size increases reaction time increases type of probe foil stimulus that should be responded negatively or target positive I regardless of set size must consider all items in set to say no for target I exhaustive search looking for foils must consider all items and higher slope whether it s yes or no you still keep going through the entire memory set slopes are same for yes and no if decision making is same then we can predict same slope I selfterminating search looking for target as soon as you reach the target you can end the search slope will not be as steep as in the no trials Yes trials on average has less number of comparisons comparison entails decisionmaking can skip rest of search and produceresult two components of stimulants I Probe target Foilnot part of trial Chapter 1 The Science of Cognition Informationprocessing analyses Define the information processing approach 0 O O the dominant approach in cognitive psychology his approach attempts to analyze cognition as a set of steps for processing an abstract entity called information EX Sternberg Paradigm account of how participants made judgments Sternberg paradigm 0 Explain parallel search and serial search I serial search content is scanned one by one individually I parallel search info is being scanned at once How does each type of search predict the set size effect I IF people perform parallel search the reaction would produce a at line menaing that the reaction time is equal I as size increases reaction time increases I reaction time does not change for parallel search vs serial How does each type of search predict the serial position effect I serial position effect ex number presented first and last more memorable would have to assume set is being viewed left to right the opposite would be parallel position effect info is being scanned at once Reaction timecomparison does not change for parallel search vs serial What does the slope re ect psychologically For example if the slope is 0 what does it mean If the slope is significantly greater than 0 what does it mean I if people perform parallel search the reaction time would produce a at line equal reaction time I for serial search the more you have to consider the more time positive increase line If the slopes for targets and foils were the same what does this result say about exhaustive search and selfterminating search I This implies that it takes the reactionconsideration time in detecting foils and targets are the same regardless of the search mechanism What does the intercept re ect The brain and cognition What are the components of a neuron O O O soma the main body of the neuron typically 5100 micrometers in diameter Dendrites short branches attached to the soma axon long tube extending from the soma can vary in length from a few mill to a meter How does information travel within a neuron O Neurons communicate by releasing chemicals called neurotransmitters from the axon terminal on one side of the synapse these chemicals act on the membrane of the receptor dendrite to change its polarization or electric potential How does information travel between neuron O O O axons provide the fixed paths by which neurons communicate with one another the axon of one neuron extends toward the dendrites of another neurons Potential changes accumulate on a cell body reach a threshold and cause an action potential t propagate down an exon tis pulse in return causes neurotransmitters to be sent from the axon terminal to the body of a different neuron causing changes in that neuron s membrane potential Cognitive importance of acetylcholine and dopamine 0 Both play key roles in cognitive functions such as learning memory and selective attention I Acetylcholine release of it by motor neurons is what causes muscles to contract is important in the brain for plasticity and formation of new memories I Dopamine important for attentional functions Hippocampus and Basal Ganglia Cognitive functions associated with the hippocampus and basal ganglia O The hippocampus located in the temporal lobe is associated with human memory damage to this area of the brain can result in amnesia O Basal Ganglia involved both in basic motor control and in the control of complex cognition Cortex What are the four lobes of the brain Their functions 0 frontal two major functions I back portion of the frontal lobe is involved with motor functions I front portion prefrontal cortex control higher level processes such as planning 0 parietal handles some perceptual functions including spatial processing and representation of the body also involved in control of attention 0 occipital contains the primary visual areas 0 temporal receives input from the occipital area and is involved in object recognition also has primary auditory areas and Wernicke s area which is involved in language processing Three organizing principles in brain 0 Redundancy different parts of the brain each contribute to solving the same problems For example vision is mediated by the eye the superior colliculus and various layers of the occipital cortex 0 Bilateral Symmetry The plane of symmetry divides the brain into a right and a left half 0 Evolutationary organization 0 Localization Primary areas and association areas 0 Broca s aphasia and Wernike s aphasia I Characteristics Broca s aphasiadamage to Broca s area resulting in speak in short ungrammatical sentences Wernike s aphasia damage to the Wernike s area of the result in pateitns speaking in fairly grammatical sentences that are almost devoid of meaning difficulty with their vocabulary and generate empty speech I Related brain regions Broca s and Wernice s areas in the left cortex of the brain important for speech Lateralization Hemispheric asymmetry 0 Left and right hemisphere I Left Hemisphere is associated with linguistic and analytic processing I Right hemisphere is associated perceptual and spatial processing I hemisheres connected by Corpus callosum which has been severed in some patients to prevent seizures 0 splitbrain patients in experiment where the word key was ashed on left side of a screen because it was on the left side of the screen it would normally be received by the right nonlanguage hemisphere 0 HOWEVER when asked what was presented on the screen the patient was not able to say because the languagedominant hemisphere did not know the left hand not right was able to pick out a key from a set of objects from view 0 Studies on splitbrain research show that right hemisphere can comprehend only the simplest linguistic commands whereas the left hemisphere displays full comprehension VS ability of the right hand left hemisphere to perform manual tasks is compared with that of the left hand right hemisphereIn this situation the right hemisphere outperforms the left Example with sensorymotor cortex Example with monkey visual cortex Neuroscience methods What does EEGERP measure 0 EEG Electroencephalgraphy records the electric potentials that are present on the scalp when used to study cognition patient is asked t respond to some stimulus and researchers are interested in discovering how processing this stimulus impacts general activity on the recordings 0 ERP eventrelated potentials averaged EEG responses aligned to a particular stimulus What does PET measure 0 PET Positron emission tomography provide relatively good information about the location of neural activity It measures metabolic rate or blood ow in various areas of the brain relying on the fact that more active areas of the brain require greater metabolic expenditures and have greater blood ow basically measuring the amount of work a brain region does What does fMRI measure 0 fMRI measures the same thing PET measures but does not require injecting the participant like PET does but relies on the fact that there is more oxygenated hemoglobin in regions of greater neural activity Temporal resolutions and spatial resolutions of EEGERP PET and fMRI 0 these imaging techniques have limitation that goes beyond temporal and spatial resolution they provide only a limited basis for causal inference Just because activity is detected in a region of the brain during a task does not mean that the region of the brain is critical to the execution of the task Qin et al 2004 study Using fMRI to study equation solving What is the main research question of the Qin et al 2004 study What task did the study adopt and why 0 Solving algebraic equations of three levels of complexity in terms of the number of steps of transformation that was required 0 Researchers wanted to track activity in the brain of different information processing components of the different levels of complex tasks motor region parietal region and prefrontal region Design of the study Findings The study showed that researchers can separately track different informationprocessing components involved in performing a complex tas Can you explain Figure 116 regardless of the time it took to solve the problem the graphs show that the motor region of the brain did not really differ because regardless of the complexity of the problem the time to press an answer key remains fairly constant Chapter 2 Class notes Perception Detectors in brain specializing in different aspects of perception Topdown vs Bottom down processes in perception our perceptions aren t what is presented to us distal stimulus vs proximal stimulus existing but not perceived O Distal Rich unlimited early information 0 proximal constrained selected late perception is constantly changing Goals of Perception O to make sense of ambiguous insufficient information 0 recognition of external objects Ambiguity one perception at a time Illusions give us perception of something that s not there 0 Constancy is opposite of illusions I allows us to not see differences I shape constancy distance cues of parts I color constancy ties to object constancy Sensation and interpretation perception Depth Perception 0 Texture gradients Dense vs Farse Dense objects appear further away vs Farse objects that appear closer 0 Relative Size objects that re the same size look bigger if they are closer vs objects further away appear smaller 0 Interposition when an object I s in front of another it appears closer than the one behind it imposer looks closer than imposed 0 Linear Perspective parts of lines that are converging seem further away and smaller than the lines that are diverging apart 0 Arial Perspective Clarity closer objects appear to be more clear unclear objects seem further away Ofar Near I Objects on horizon appear smaller and further away than those above 0 Motion Parallax Shen we move around objects that are nearest move in opposite direction of you and faster move away from your vision faster objects that are further away move in the same direction as you and slower takes longer to disappear from vision 0 Binocular Depth Cues I Binocular convergence degree of convergence of eyeballs I close objects eyeballs converge closer high convergence 0 far objects eyeballs diverge low convergence 0 muscular movement is on cue I Binocular disparity Degree of disparity of images projected to your eyes I what your left eye sees is different than what your right eye sees 0 Degree of difference is smaller when object is further away vs closer objects 0 Grouping I Boundary Assignment controls what you perceive in the moment 0 Gestalt Principles I How things are grouped that lead to perception Palmer 1977 coding imagesremember based on closure and good continuity I Proximity when things are equal things that are close are grouped together I similarity when things are equal similar things are grouped together I Good Continuitv things that look good together will be grouped together I Closure We have tendency to perceive things in closed from rather than open even if it is not visually apparent Chapter 2 Study Guides Visual Information Processing Visual Perception in the Brain Visual Agnosia result of damage to certain brain regions in individuals aren t blind but are unable to recognize anything visually results from neural damage ex soldier with this could recognize objects by their feel smell or sound but he was unable to distinguish a picture of a circle from that of a square or to recognize faces or letters etc 19 27 Provide a short description of aDDerceDtive agnosia and associative agnosia two tVDes of visual agnosia Apperceptive agnosia inability to recognize simple shapes such as circles or triangles or to draw shapes shown Associative agnosia in contrast to aperceptive agnosia associative agnosia ability to recognize simple shapes and can successfully copy drawings even of complex objects however they are unable to recognize the complex objects EX Figure 22 shows the original drawing of an achor and a copy made by a patient with associative agnosia despite being able to produce a relatively accurate drawing the patient could not recognize this object as an anchor called it umbrella How are they different from each other Patients apperceptive agnosia are generally believed to have problems with early processing of information in the visual system In contrast patients with associative agnosia are thought to have intact early processing but to have difficulties with pattern recognition which occurs later Early Visual Information Processing begins in the eye light passes through lens and the vitreous humor and falls on the retina at the back of the eye one of functions of early visual processing is to sharpen image To types of photoreceptors in eye cones and rods 1 cones involved in color vision and produce high resolution and acuity 2 Rods requires less light energy to trigger response but produce poorer resolution principally responsible for th less acute black and white vision experienced at night From the primary visual cortex information tends to follow two pathways 1 what pathway goes to regions of the temporal cortex specialized for identifying objects 2 where pathway goes to parietal regions of the brain specialized for representing spatial information and coordinating vision with action Depth and Surface Perception Texture gradient tendency of evenly spaced elements to appear more closely packed tgether as the distance from the viewer increases Steropsis ability to perceive 3D depth based on the fact that each eye receives a slightly different view of the world Motion Parallax the images of distant objects will move across the retina more slowly than the images of closer objects Object Perception Gestalt principles of organizations explains how the brain segments visual scenes into objects Proximity elements close together tend to organize into unites thus we perceive four pairs of lines rather than eight separate lines Similarity objects that look alike tend to be grouped together Good continuity objects that look good together grouped together Closure we perceive the occluded part as a circle not as having a wiggly jagged or broken border Palmer 1977 study Be able to explain the design and the results I Studied recognition of shapes 214 first showed participants stimuli and asked tem to decide whether the fragments depicted in figures 214b through e were part of the original figure I stimulus tends to organize self into a triangle principle of closure and a bent letter 11 principle of good continuation I palmer found that participants could recognize the parts most rapidly when they were the segments predicted byt ehh gestalt principles How does the result of Palmer 1977 support Gestalt principles of organizations I Results allow us to see that recognition depnds critically on the initial segmentation of the figure Recognition can be imared when the gestaltbased segmentation contradicts the actual pattern structure Visual pattern recognition T emplateMatching Moc theory of perception that proposes that a retinal image of an object Is faithfully transmitted to the brain and the brain attempts to compare the image directly to various stored patterns called templates 1 basic idea perceptual system tries to compare the image of a letter to the templates it has for each letter and then reports the template that gives the best match How does the featureanalysis theory explain pattern recognition Evidence for the theory In the feature analysis model stimuli are throught of as combbinations of elemental features EX the capital letter AA can be seen as consisting of a horizontal two diagonals I opposite orientation a line intersection symmeter and a feature called vertical discontinuity feature analysis involves recognizing first the separate features that make up a pattern and then their combination Evidence for theorv if letters have many features in common as C and G do for example evidence suggests that people are particularly prone t confuse the kinney Marsetta amp Showman 1966 How does the recognitionbvcomDonents theorv eXDlain pattern recognition Evidence for the theorv The recognitionbycomponents theory proposes that there are three stages in our recognition of an object as a configuration of simpler components 1 The object is segmented into a set of basic subobjects via a process that re ects the output of early visual processing 2 Once an object has been segmented into basic subobjects one can classify the category of each subobject Biederman suggested that there are 36 basic categories of subobjects called geons geometric ions What are the two opposing ideas regarding face recognition What evidence is available for each theory 1 we have special mechanisms to recognize someone s face Special cells that respond preferentially to the faces of other monkeys have bene found in the temporal lobes of monkeys damage to this part of the brain in humans can result in prosopagnosia difficulties in recognizing faces Studies using fMRI have found a particular region of the temporal lobe called the fusiform gyrus that responds when faces are present in the visual field 2 Other evidence from studies investigating the recognition of upside down faces vs upright faces shows that people are much better at recognizing faces when the faces are presented in an upright position as opposed to upside down decreased recognition in upside down faces reduced fMRI response in the fusiform gyrus when inverted faces are presented Speech recognition What are three dimensions of speech sound 1 Consonantal feature the consonantlike quality of a phoneme in contrast to a vowel like quality 2 Place of Articulation Refers to the location at which the vocal track is closed or constricted in the production of a phoneme 3 Voicing feature of phonemes produced by vibration of the vocal cords For example the phoneme z in the word zip as voicing whereas the phoneme s in the word sip does not Can you explain how different speech sounds of English are distinguished along those dimensions What evidence is available for feature analysis in speech perception What is VOT Voice Onset Time refers to the time between the beginning of the pronunciation of the word and the onset of the vibration of the vocal chords For example when you say quotbaquot your vocal chords vibrate right from the start When you say quotpaquot your vocal chords do not vibrate until after a short delay Be able to explain the categorical perception of speech sound to your friends and provide the best explanation Categorical perception of speech is the perception of stimuli as belonging in distinct categories Pg 46 Figure What is topdown processing when context or general knowledge of the world guides perception example the image of the cow prior knowledge of what a cow s face looks like in uenced perception of a cow in the image Be able to explain the word superiority effect to your friends and provide the best explanation and its implication refers to the phenomenon that people have better recognition of letters presented within words as compared to isolated letters and to letters presented within non word orthographically illegal unpronounceable letter array strings Example figure 227 with the word WORK sometimes using context we do not need to perceive every letter in a string of cords to be able to read it Context and pattern recognition How did Massaro conduct his experiment to examine the contributions of context topdown and features bottomup to pattern recognition and what is his conclusion argued that the perceptual information and the context provide two independent sources of information about the identity of the stimulus and that they are just combined to provide a best guess of what the stimulus might be In experiment 4 quadrants representing four responsibilities in the amount of contextual evidence only E can make a word only a C can make a word both letters can make a word or neither can make a word i participants brie y exposed to these stimuli and asked to identify the letter ii as the image of the letter itself provided more evidence for an e the probability of the participants identifying an e went up similarly the probability f identifying an e increased as the context provided more evidence Conclusion contextual information combines independently with stimulus information to determine what pattern is perceived Explain the phenomenon of phoneme restoration effect and its significance in speech perception a perceptual phenomenon where under certain conditions sounds actually missing from a speech signal can be restored by the brain and may appear to be heard The effect occurs when missing phonemes in an auditory signal are replaced with a masking noise resulting in the brain filling in absent phonemes The effect can be so strong that some listeners may not even notice that there are phonemes missing This effect is commonly observed in a conversation with heavy background noise making it difficult to properly hear every phoneme being spoken Different factors can change the strength of the effect including age and gender Explain the phenomenon of change blindness and its significance regarding the context effect People ae unable to keep track of all the information in a typical complex scene if elements of the scene change at the same time as some retinal disturbance occurs such as an eye movement r a scenecut in a motion picture people often fail to detect the change ex the color of a car in a picture might change and the change might not be noticed experiment demonstrating change blindness experimenter stopped pedestrians on Cornell University s campus and asked for directions while the participant was giving the directions workers carrying a door passed between the experimenter and the participant and an accomplice took the palace of the experimenter Only 715 of the participants noticed the change i participants thought they were giving directions to a student and as long as the changed experimenter fit that interpretation they did not notice him as different 09 17 15 Class lecture CH 2 continue Top down vs Bottom up processing review how these processes work together 0 Massaro experiment 0 results show that context does not override stimulus and vice versa they are equal ch 3 Attention Where is Waldo image class exercise 0 integration of features in an object which involves serial processing 0 greater locations to examine will take longer to locate the target candidate locations O attention process deals with limited resources Attention process is a selection process attention selectin the ultimate process deals with limited resources external world cluttered with resources so we have to apply certain selection criteria to deal with the overwhelming stuff serial search whether you search from short or longterm memory still implies serial search selection critera without a criteria we cannot select anything Cherry 1953 0 Dichotomic listening test 0 shadowing his right ear requires both semantical and physical analysis accessing semantical analysis is important for shadowing behavior 0 what is picked up by the subject from the unattended channel Chapter 3 Attention amp Performance AUDITORY ATTENTION 0 Describe Cherrv s dichotic listening experiment and the maior findings of the sttulL 0 Participants wear a set of headphones they hear two messages at the same time one in each ear and are asked to shadow one of the two messages ie repeat back the words from that message only 0 Findings most participants were able to attend to one message and tune out the other very little information about the unattended message is processed in a dichotic listening task all that participants could report about the unattended message is whether it was a human voice or a noise whether the human voice was male or female and whether the sex of the speaker changed during the test couldn t tell language spoken or any of the words even if same word was repeated multiple times 0 example of goaldirected processing listener selects the message to be processed O I important stimulus information can disrupt our goals ex listening intently to one person and hear our names mentioned by someone else this makes ithard to keep your attention on what the original speaker is saying experiment can be compared to performing this task and being at a party where a guest tunes in to one message a conversation and filters out others 0 How does the filter theorv or eaer selection theorv explain attentional selection 0 O O sensory information comes through the system until some bottleneck is reached at that point a person chooses which message to process on the basis of some physical characteristicl lters out the other information we select a message to process on basis of physical characteristics such as ear or pitch messages entering each ear arrive on different nerves nerves vary in which frequencies they carry from each year so ins some way the brain selects certain nerves to pay attention to people can also select messages to process on the basis of their semantic content I Gray and Wedderburn study 1960 demonstrated that participants can use meaningfulness to follow a message that jumps back and forth between the ears I in one ear they might be hearing words dogs six eas while at the same time hearing the words eight scratch tw in the other ear instructed to shadow the meaningfulness message participants would report dogs scratch eas thus participants can shadow a message on the basis of meaning rather than on the basis of what each ear physically hears I sometimes people use a physical characteristic e g a particular ear to select which message to follow and sometime they chose semantic content lter model proposes that e use physical features such as ear or pitch to select one message to process but it has been shown that people can also use the meaning of the message as the basis for selection 0 What is countereviglence of the filter theory 0 Reisman 1964 proposed a modification of the filter theory attenuation theory 0 J A Deutsch and D Deutsch 1963 proposed an alternative explanation lateselection theory 0 Contrast the attenuation theorv and the lateselection theorv provide supporting evidence for each theory 0 Attenuation theorv This model hypothesized that certain messages would be attenuated weakened but not filtered out entirely on the basis of their physical properties in a dichotic listening task participants would minimize the signal from the unattended ear but not eliminate it Semantic selection criteria coul apply to all messages whether they were attenuated or not I in experiment most participants actually continued to shadow the prescribed ear it was easier to follow the message that is not being attenuated than to apply semantic criteria to switch attention to the attenuated message LateSelection theorv proposes that all the information is processed completely without attenuation The hypothesis was that the capacity limitation is in the response system no the perceptual system People can perceive multiple messages but that they can only say one message at a time therefore people need some basis for selecting which message to shadow if they use meaning as the criterion they will switch ears to follow the message if they use the ear of origin in deciding what to attend to they will shadow the chosen ear ComparisonEvidence both models assume that there is some filter or bottleneck in processing The attenuation theory assumes that the filter selects which message to attend to whereas the earlyselection theory assumes that the filter occurs after the perceptual stimulus has been analyzed for verbal context 39 Treisman and Geffen tested difference between two theories using a dichotic listening task where participants had to shadow one message while also processing both messages for a target word if they heard the target word they were to signal by tapping 39 according to the lateselectin theory messages from both ears would get through and participants should have been able to detect the critical word equally ill in either ear in contrast the attenuation theory predicted much less detection in the un shadowed ear because the message would be attenuated 39 in the experiment participants detected 87 of the target words in te shadowed ear and only 8 in the un shadowed ear Other evidence consistent with the attenuation theory was reported VISUAL ATTENTION the focus of visual attention is not always identical with the part of the visual field being processed by the fovea people can be instructed to fixate on one part of the visual field making that part the focus of the fovea while attending to another nonfoveal region of the visual field Visual attention directed to a spatial location appears to enhance the cortical signal from that location if a person attends to a particular spatial location a distinct neural response in th visual cortex occurs within 70 to 90 ms 0 when a person is attending to a particular object ex chair rather than a table rather than to a particular location in space we do not see a response for more than 200 ms When people attend to a particular rspatial location there is greater neural processing in portions of the visual cortex corresponding to that location 0 How M Posner Nissen amp Ogden test the characteristics of visual attention 0 had participants focus on a constant point and then presented the with a stimulus amp degrees to the left or the right of the fixation pint In some trials participants were told on which side of he stimulus was likely to occur in other trials there was no such warning the warning was correct 80 of the time but 20 of the time the stimulus appeared on the unexpected side researchers monitored eye movements and included only those trials in which the eyes had stayed on the fixation point ndings participants were faster when the stimulus appeared in the expected location and slower when it appeared in the unexpected location thus they were able to shift their attention from where their eyes were fixated I people can attend to regions of the visual field as far as 24 degrees from the fovea people usually move their eyes so that the fovea processes the portion of the visual field to which 0 they are attending Successful control of eye movements requires us to attend to places outside the fovea we must attend to and identify an interesting nonfoveal region so that we can guide our eyes to fixate on that region to achieve the greatest acuity in processing it people can focus their attention on parts of the visual eld and move their focus of attention to process what they are interested in 0 What is the Spotlight metaphor What neural evidence of visual attention is available 0 0 Explain the feature search and coniunction search 0 0 It is necessary to search through a visual array for an object only when a unique visual feature does not distinguish that object Feature Search Feature searches can be performed fast and preattentively for targets defined by only one feature such as color shape perceived direction of lighting movement or orientation Features should quotpop outquot during search and should be able to form illusory conjunctions Conjunctive Search occur with the combination of two or more features and are identified serially Conjunction search is much slower than feature search and requires conscious attention and effort In multiple experiments some referenced in this article Treisman concluded that color orientation and intensity are features for which feature searches may be performed 0 What is the binding problem What gloes it take to bind features What gloes the phenomenon of Msorv coniunction tell llS about binding 0 O the binding problem refers to the question of how the brain puts together varous features in the visual field featureintegration theory proposed by Treisman as an answer to the binding problem She proposed that people must focus their attention on a stimulus before they can synthesize tis features into a pattern EX in the case of the red vertical line combining the vertical feature and the red feature the visual system can first direct its attention to the location of the red vertical bar and synthesize that object then direct its attention ot he green horizontal bar and synthesize that object I people must search through an array when they need t synthesize features to recognize an object like when trying to identify a K which consists of a vertical line and two diagonal lines When an object in an array has a single unique feature such as a red jacket or a line at a particular orientation we can attend to it without search The phenomenon of illusory conjunction is where people report combinations of features that did not occur For instance Treisman looked at what happens to feature combinations when the stimuli are out of the focus of the attention I Participants were asked to report the identity of two black digits ashed in one part of the visual field participants reported seeing illusory conjunctions of features almost as often as they reported seeing correct combinations Results of the study found that it appears we are able to combine features into an accurate perception only when our attention is focused on an object Otherwise we perceive the features but may well combine thn into a perception of objects that were never there I For feature information o be synthesized into a pattern the information must be in the focus of attention VISUAL NEGLECT visual attention to a spatial location results in enhanced activation in the appropriate portion of the primary visual cortexthe neural structures that control the direction of attention however appear to be located in the parietal cortex 0 De ne visual neglect 0 a condition in which aspects of visual stimulus are ignored by the subject due to various cortical abnormalities an individual can see all of the visual field binocularly but somehow ignores objects on one side heshe is conscious of objects in the left visual field but shows not pay attention to them 0 Relation between damaggl brain regions and behavioral deficit O damage to the right parietal region produces onesided attentional deficit I because the right parietal lobe processes the left visual field damage to the right lobe impairs its ability to draw attention back to the left visual field once attention is focused on the right visual field I unilateral visual neglect patients with damage t the right hemisphere completely ignore the lest side of the visual field and patients ith damage to the left hemisphere ignore the right side of the visual field I right parietal lobe spatial attention not just visual more responsible for the spatial allocation of attention than is the left parietal lobe which is why right parietal damage tends to produce such dramatic effects left parietal damage tends to produce a subtler pattern of deficits O parietal regions are responsible for the allocation of attention with the ight hemisphere more concerned with global features and the left hemisphere with local features 0 Posner Cohen amp Rafal 1982 0 Explain the design 0 Explain the results 0 Hemispheric asymmetry in visual neglect Objectbased Attention 0 Define obiectbased attention when people focus their attention on particular objects rather than regions of space 0 Behrman Zemel amp Moser 1998 example of research demonstrating that people sometimes find it easier to attend to an object than to a location 0 design Participants were asked to judge whether the numbers of bumps on the two ends of objects were the same Left column shows instances in which the numbers of bumps were the same the right column instances in which the numbers were not the same 0 results participants made these judgments faster when the bumps were on the same object than when they were on different objects this result occurred despite the fact that when the bumps were on different objects they were located closer together which should have facilitated judgment if attention were space based 0 Explain why this study supports objectbased attention than spacebased attention I participants shifted attention 0 one object at a time rather than one location at a time therefore judgments were faster when the bumps were all on the same object because participants did not need to shift their attention between objects 0 Inhibition of return other evidence for objectcentered attention 0 Define inhibition of return if we have looked at a particular region of space we find it a little harder to return our attention 0t hat region if we move our eyes to location A and then to location B we are slower to return our eyes to location A than to some new location C EX if we are searching for something and have already looked at a location we should prefer our visual system to find other locations to look at rather than return to an already searched location 0 What is the benefit of using a dynamic than static inhibition of return paradigm when testing the objectbased attention 0 Explain the experiment and the results I Tipper Driver and Weaver 1991 performed one demonstration of the inhibition of return that also provided evidence for objectbased attention I Participants viewed three squares in a frame in one condition the squares did not move the participants attention was drawn to one of the outer squares when the experimenters made it icker and then 200ms later attention as drawn back to the center square when that square ickered a probe stimulus was presented in one of the other positions and participants were instructed to press a key indicating what they had seen the probe on average they took 420 ms to see the probe when it occurred at the outer square that had not ickered and 460 ms when it occurred at the outer square that had ickered 0 the 40 ms advantage is an example of a spatially defined inhibition of return people are slower to move their attention to a location where it has already been 0 visual attention can be directed wither toward objects independent of their location or toward locations independent of what objects are present Central Attention 0 Byme amp Anderson 0 What tasks 0 What results 0 Support what I Schumacher et a1 0 What tasks 0 What results 0 Support what 0 How would the discrepancies between Byrne amp Anderson and Schumacher et a1 studies be reconciled I Stroop 0 What is the Stroop task 0 What are the characteristics of the Stroop type of tasks 0 What is Congruency O MacLeod amp Dunbar I What tasks did they use I Results differed from the beginning of practice to the end of practice How did they differ What does this suggest 0 What are the roles proposed for the prefrontal cortex versus anterior cingulate cortex in relation to the type of con ict induced by the Stroop task
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