Attention PDF

ATTENTION Attention: the ability to focus on specific stimuli or locations Selective attention: the focusing of attention on one specific location, object, or message Overt attention: the process of shifting attention from one place to another by moving the eyes Covert attention: attention...

ATTENTION Attention: the ability to focus on specific stimuli or locations Selective attention: the focusing of attention on one specific location, object, or message Overt attention: the process of shifting attention from one place to another by moving the eyes Covert attention: attention is shifted without moving the eyes commonly referred to as seeing something “out of the corner of the eye” Divided attention: attending to 2+ things at once can be overt, covert, or a combination of the two Early studies: results & consequences Limited capacity: people are unable to identify both messages at once Effective selectivity: people could identify well one message when the 2 differed in physical characteristics; not when when they differed in context Consequences of efficient selection: only crude characteristics of the unattended message were identifiable Input attention: information that is processed without allocation of resources automatic SELECTIVE ATTENTION SELECTIVE ATTENTION AS FILTERING Cherry’s Dichotic listening experiment Methods: different messages are presented to the two ears pay attention to the message presented to one ear (attended message), repeating it out loud as they are hearing it shadowing: repeating a message out loud ignore the message presented to the other ear (unattended message) Results: listener can attend to just one message BROADBENT’S EARLY SELECTION MODEL (AKA BOTTLENECK) Sensory memory holds all of the incoming information for a fraction of a second Filter identifies the attended message based on its physical characteristics and lets only this message pass through to the detector in the next stage Characteristics like speaker’s tone of voice, pitch, speed of talking, and accent  All other messages are filtered out/discarded information in the unattended message should not be accessible to consciousness P-system (filter): probability that the message will be recognized and processed What is relevant or important Store of conditional probability: past events help you predict the message, aiding in selecting what you’ll allocate attention to Detector processes information to determine higher-level characteristics of the message, such as its meaning Because only the important, attended information has been let through the filter, the detector processes all of the information that enters it Short-term memory receives the output of the detector Moray’s Shadowing Experiment Asked to focus on one and repeat simultaneously (shadowing) Asked what they remembered about the unattended message Results: People could not recall the information But they could recall gender, accents As they start shadowing, they would automatically switch to unattended ear Locked into a message, not necessary attending: pre-attentive analysis The sentence trumps the list of words Cocktail party effect: phenomenon, in which a person is selectively listening to one message among many yet hears his or her name or some other distinctive message such as “Fire!” that is not being attended information presented to the unattended ear is processed enough to provide the listener with some awareness of its meaning TREISMAN’S ATTENUATION MODEL language and meaning can be used to separate the messages selection occurs in two stages STAGE 1: Pre-attentive analysis the analysis of the message proceeds only as far as is necessary to identify the attended message Once the attended and unattended messages have been identified, both messages are let through the attenuator the attended message emerges at full strength  the unattended messages are attenuated Attenuator analyzes the incoming message: physical characteristics: high-pitched or low-pitched, fast or slow language: how the message groups into syllables or words meaning: how sequences of words create meaningful phrases STAGE 2 the message is analyzed by the dictionary unit Dictionary unit: contains stored words, each of which has a threshold for being activated words that are common or especially important, such as the listener’s name, have low thresholds Uncommon words or words that are unimportant to the listener have higher threshold How do we control distractors? Early selection effect: focusing attention on task-relevant stimuli can exclude distractors from early perceptual processing Focused-attention prevents distractors from being processed Late-selection effect: focusing attention on task-relevant stimuli prevents distractors form controlling behaviours and memory Distractors are processed but discarded by current goals McKay’s Late Selection Model most of the incoming information is processed to the level of meaning before the message to be processed is selected Early selection can be demonstrated under some conditions and later selection under others, depending on the observer’s task and the type of stimuli presented ALL BOTTLENECK THEORIES: Agree on: Information is picked up by a sensory register Selected by detection device Further processed n STM Disagree on : Nature of pre-attentive analysis Nature of the detection device Cognitive Resources, Cognitive Load, Task-Irrelevant Stimuli Cognitive resources: a person has a certain cognitive capacity, which can be used for carrying out various tasks Cognitive load: the amount of a person’s cognitive resources needed to carry out a particular cognitive task Low-loads: use up only a small amount of the person’s cognitive resources especially easy, well-practiced tasks High-load: use more of a person’s cognitive resources difficult and perhaps not as well practiced tasks Low vs High Capacity & Load (Lavie) Distractor effects are greater in low perpetual load conditions than in than in high ones: High perceptual load engages full capacity in relevant processing leaving no spare activity for task irrelevant stimuli In low perpetual load, any capacity not taken up would involuntarily spill over to the perception or task-irrelevant distractors You can do 2 things at once as long as these activities do not exceed the number of available resources Performance on the 2nd task will decline if the sum of perceptual load is maxed Flanker compatibility task: participants are told to carry out a task that requires them to focus their attention on specific stimuli and to ignore other stimuli ignore the “flanker” stimuli that are presented on either side (task-irrelevant stimuli) that aren’t needed for the primary task Compatible flankers: associated with the same response as the target Faster response Incompatible flankers: associated with a different response than the target typically respond more slowly when incompatible flankers are present the incompatible flanker causes a slower response in the low-load condition but has no effect in the high-load condition (Lavie) Cognitive resources are available = incompatible flankers intrude and cause slower responding Flanker effect demonstrates that even though participants were told to ignore the flankers, they still processed information from them Stroop Effect task-irrelevant stimuli are extremely powerful, because reading words is highly practiced and has become so automatic that it is difficult not to read them the names of the words cause a competing response and therefore slow responding to the target (the colour of the ink) Enduring dispositions: control of involuntary attention: pop-out features Momentary tasks intentions: things that depend on the situation (current goals) disposition/available resources to allocate resources to a give source of information Arousal/cognitive load will determine how much you can allocate High = disruption/depletion of allocation Low = able to allocate to different tasks DIVIDED ATTENTION Automaticity Occurs within a restricted domain of representation (well-practiced) Does not occur within less-restricted domain (complex tasks, not practice) Divided attention & PRACTICE: AUTOMATIC PROCESSING After a certain amount of repetition (600 trials), participants reported that the task had become “automatic” divide their attention to deal with all of the target and test items simultaneously Automatic processing: a type of processing that occurs without intention (happens automatically without intent) at a cost of only some of a person’s cognitive resources Attentional resources & practice playing Tetris Performance in tasks improves with practice High activity and attentional demands when naive Low activity and attentional demands when experienced Cortical thickening increases with practice ATTENTION & AUTOMATICITY A lot of attention is “input-driven” (bottom-up) Self selecting input (visual/auditory) a lot of attention is ‘controlled’ allocation of resources is under control Many tasks become “automatic” allocation of resources is also “automatic” Attentional demands decrease WHEN TASKS ARE HARDER: CONTROLLED PROCESSING Controlled processing: paying close attention at all times search for the target among the distractors in a much more focused and controlled way than in the consistent mapping condition Memory search task Response (yes/no) should be an effect of: memory-set size: number of elements that the subject has to study target-display size: number of elements appearing in subsequent frames, to which subjects have to respond yes/no whether they appeared in the “memory” frame Variations in memory search tasks Varied mapping condition: targets or distractors in one trial can appear as targets or distractors in another trial when the rules keep changing from trial to trial much more difficult participants never achieved automatic processing Consistent mapping: Targets from one trial are never distractors in another trial (and vice versa) Results: RT increases as the memory set and display size increases More elements in the memory Varied mapping has highest RT regardless of frame size and memory set size DISTRACTIONS WHILE DRIVING Driving: task that demand constant attention risk of a collision was 4x higher when using a cell phone hands-free cell phone units offered no safety advantage related to the use of cognitive resources distraction of attention associated with talking on a cell phone can degrade driving performance ATTENTION & VISUAL PERCEPTION INATTENTIONAL BLINDNESS attention is focused on one task and then determining whether the person perceived an easily visible nearby stimulus Inattentional blindness: “blindness” to the unattended test object when observers are attending to one sequence of events, they can fail to notice another event, even when it is right in front of them CHANGE DETECTION to demonstrate how a lack of attention can affect perception and how attention is necessary for perception Change blindness: difficulty in detecting changes in scenes when a cue was added indicating which part of a scene had been changed, participants detected the changes much more quickly Detecting change blindness requires focus attention Feature combination: combination of single features Similar to illusory conjunctions Ex: false memories IMPLICATIONS because there are usually so many stimuli present in the environment that we are able to pay attention to only a small fraction of these stimuli at any point in time means that we are constantly missing stimuli in the environment cognitive system has the ability to “fill in” the blanks because of our knowledge of regularities in the environment Enable to predict what is likely to be happening on the side without being aware of every detail Exogenous attention: Automatic attraction of attention by a sudden visual or auditory stimulus Endogenous attention: consciously decide to scan the environment perhaps to find a specific stimulus or to keep track of what is going on EYE MOVEMENTS, ATTENTION, AND PERCEPTION Fixations: places where the eyes briefly paused Unfamiliar scene: 3 per second Saccadic eye movements: movements of the eye from one fixation to the next BOTTOM-UP DETERMINANTS OF EYE MOVEMENTS Attention influenced by stimulus salience Stimulus salience: the physical properties of the stimulus such as colour, contrast, or movement Distractors Features that catch your attention Objects Spatial locations Sensory modalities Time points (time events/sequences) depends solely on the pattern of light and dark, colour and contrast in a stimulus TOP-DOWN DETERMINANTS OF EYE MOVEMENTS Meaning attracts attention Scene schemas: observer’s knowledge about what is contained in typical scenes attention is affected by their knowledge of what is usually found in the scene attention is influenced by a particular person’s knowledge and interests eye movements determined primarily by the task Task rules Responses LTM Working memory LOOKING WITHOUT PAYING ATTENTION Although eye movements often indicate where a person is directing attention, it is possible to be looking directly at something without paying attention Attention in Social Situations: The Case of Autism Attention is a crucial component of social situations what others are saying facial expressions body language direction of another person’s gaze is a determinant of attention Autism is a developmental disorder in which one of the major symptoms is withdrawal of contact from other people typically do not make eye contact with others difficulty telling what emotions others are experiencing in social situations EYE FIXATIONS nonautistic observers fixated on eyes in order to access his emotional reaction follows the pointing movement from Segal’s finger the autistic observers looked near Sandy Dennis’s mouth or off to the side looks elsewhere first, then back and forth between the pictures