Chapter Three: Perceptual Processes II: Attention and ConcsiousnessChapter Introduction-AttentionoA concentration of mental activity that allows you to take in a limited portion of the vast stream of information available from both your sensory world and your memoryoUnattended items lose out and they are not processed in detail oVitally important "gatekeeper"-Attention tasks use both bottom up and top down processing-Bottom up: oWe sometimes concentrate our mental activity because an interesting stimulus in the environment ahs captured our attention-Top down:oWe concentrate our mental activity because we want to pay attention to some specific stimulus-Includes change blindness and inattentional blindness and ambiguous figure ground relationships -Attention helps regulate how man items you can process in working memory-Also intertwined with long term memory-We consider now divided attention and four kinds of selective attention Several Kinds of Attention Processes-Divided attention, selective attention, dichotic listening task, stroop task, visual searches, saccadic eye movements Divided Attention-Divided attention taskoTry to pay attention to two or more simultaneous messages, responding appropriately to each messageoBoth your speed and accuracy suffer-MultitaskoTrying to accomplish two or more tasks at the same time oStrain the limits of attention, as well as limits of working memory and long term memory oDriving studies-Participants who used cell phones showed a form of inattentional blindness -Listening to a passenger carrying on a conversation is even more dangerous for the driverIf you hear half a conversation, its less predictable; therefore drivers are distracted trying to guess content of other half -Divided attention task requires people to pay equal attention to two or more kinds of information-Selective attention tasks oRequire people to pay attention to certain kinds of information, while ignoring other ongoing informationoSimplifies our lives-Four different kinds of selective attention tasks: dichotic listening, stroop effect, visual search, and saccadic eye movements Dichotic Listening-Dichotic listeningoStudied by asking people to wear earphones; one message is presented to the left ear, and a different message is presented to the right earoParticipants asked to shadow the message in one ear-The listen to that message and repeat it after the speaker-In general, people can only process one message at a time-People are more likely to process the unattended message whenoBoth messages are presented slowlyoThe main task is not challengingoThe meaning of the unattended message is immediately relevant-Cocktail party effectoSometimes notice when name is inserted in unattended message-People with relatively low working memory capacity have difficulty blocking out the irrelevant information such as their name-They are easily distracted from the task they are supposed to be completing The Stroop Effect-Stroop EffectoPeople take a long time to name the ink color when the color is used in printing an incongruent word; in contrast, they can quickly name that same ink color when it appears as a solid patch of color -People take longer to pay attention to a color when they are distracted by another feature of the stimulus, namely, themeaning of the name itself-Parallel distributed processing approachoAccording to this, stroop task activates two pathways at the same time-One pathway is activated by the task of naming the ink color-The other by the task of reading the wordoInterference occurs when two competing pathways are active at the same time; task performance suffers-Emotional Stroop TaskoPeople are instructed to name the ink color of words that could have strong emotional significance to themoRequire more time to name the color of the stimuli oPeople with phobias are significantly slower on anxiety arousing words than on control words oPeople with phobic disorders are hyper alert to words relating to their phobia, and show attentional bias to meaning of these stimuli-Attentional biasoA situation in which people pay extra attention to some stimuli or some features-Cognitive behavioral approachoPsychological problems arise from inappropriate thinking (cognitive factors) and inappropriate learning (behavioral factors)oStudy showing relationship between women's potential for eating disorders and their thought patterns about words related to body shape Visual Search-Visual searchoObserver must find a target in a visual display that has numerous distractors-People more accurate in identifying a target if it appears frequently -Isolated feature/combined feature effectoIf the target differed from the irrelevant items in the display with respect to a simple features such as color observers could quickly detect the target oPeople can typically locate an isolated feature more quickly than a combined feature-Feature-present/feature-absent effectoOur cog processes handle positive info better than negative infooPositive --> feature is present oNegative --> feature is absentoPeople can typically locate a feature that is present more quickly than a feature that is absentoPresent feature --> bottom up processoAbsent feature --> both bottom up and top down-Substantially more challenging because people examine every item, one at a timeoEasier to spot a movement present object than a movement absent object Saccadic Eye Movements During Reading-Saccadic eye movementoBrings the center of your retina into position over the words you want to read -Fovea: better acuity than other retinal regions-People make between 150000 and 200000 saccadic movements every day-A fixation occurs during the period between two saccadic movements when your visual system pauses briefly in order to acquire info that is useful for reading-Alternating between jumps and pauses-Perceptual spanoNumber of letters and spaces that we perceive during a fixationoFor english: very lopsided-4 letters to left and 15 letters to right -Show several predictable patternsoEye moves toward center of a word rather than to a blank spaceoJumps past short words that appear frequently in a language and words that are highly predictable in a sentenceoSixe of saccadic movement is small if next word is misspelled or if it is unusual -Large saccadic movement would not be useful if the material is challenging-Good readers: make larger jumps; less likely to make regressionsoMoving their eyes backward to earlier material in the sentence