PSYC 310 1st Edition Lecture 7Outline of Last Lecture I. AttentionII. Dichotic ListeningIII. Broadbent’s Filter ModelIV. Treisman’s Attenuation TheoryV. Late Selection ModelsVI. Flanker Compatibility TaskVII. Selective AttentionOutline of Current Lecture I. Divided AttentionII. Attention and Visual PerceptionIII. Overt Attention & Covert AttentionIV. Bottom-up & Top-Down Determinants of Eye MovementV. Object-Based Visual AttentionVI. Feature Integration TheoryVII. Attention Processing & Attention in Social Situations: AutismCurrent LectureI. Divided Attentiona. Performance drops when attention is divided between multiple tasksb. Practice enables people to simultaneously do two things that were difficult atfirsti. After hours of practice, participants could read passages and categorize dictated wordsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.c. Schneider and Shiffrin (1997)i. On each trial, participant must determine if target stimulus is present in any of several test framesii. Divide attention between remembering target and monitoring rapidly presented stimuli1. Memory set: 1-4 target characteristics2. Test frames: could contain random dot patterns, a target, & distractorsiii. Consistent mapping condition: target was always a number & distractors were always lettersiv. Varied mapping condition: both targets and distractors were lettersd. Consistent Mapping Conditioni. Over time, participants became able to divide their attentionii. Automatic processing occurs without intention and only uses some of a person’s cognitive resourcese. Varied Mapping Conditioni. Rules change from trial to trial1. What was a distractor might now be the targetii. Over time, participants never achieved automatic processingiii. Controlled processing: participants paid close attention, and their search was slow and controlledf. 100-car naturalistic driving studyi. Video Recorders placed in carsii. 80% of crashes involved divided attentioniii. 22% of near crashes involved cell phone useiv. Risk of accident is four times higher when using a cell phoneg. Simulated Driving Taski. Participants on cell phone missed twice as many red lights and took longer to apply the brakes1. Same result using “hands-free” cell phoneII. Attention and Visual Perceptiona. Inattentional Blindness: a stimulus that is not attended is not perceived, even though a person might be looking directly atb. A stimulus presented while completing another task might not be rememberedc. Change Blindness: if shown two versions of a picture, differences between them are not immediately apparenti. Task to identify differences requires concentrated attention and searchIII. Overt Attention & Covert Attentiona. Overt Attention:i. Eye movements, attention and perception1. Saccades: rapid movements of the eyes from one place to another2. Fixations: short pauses on points of interest3. Studied by using an eye trackerb. Covert Attention:i. We can direct our attention to a location in our periphery without eye movementii. Pre-cueing: providing some hint at where a target stimulus will appear1. Reaction time (RT) task2. Participants respond faster to a light at an expected location than at an unexpected location3. Even when eyes kept unfixediii. Physiology of Covert Attention:1. Monkey trained to fixate eyes on a dot while a peripheral light was flasheda. Fixation only: monkey was to release bar when the fixation light dimmedb. Fixation and Attention: Monkey was to release bar when peripheral dimmed2. Recording from a cell that responded to the peripheral light showed greater activity with attentiona. Peripheral light always had the same representation onthe retinaIV. Bottom-up & Top-down Determinants of Eye Movementa. Bottom-up:i. Stimulus salience: areas that stand out and capture attention1. Bottom-up process2. Depends on characteristics of the stimulus3. Color and motion are highly salientb. Top-down:i. Scene Schema: knowledge about what is contained in typical scenes1. Help guide fixations from one area of a scene to another2. Objects that do not belong are looked at moreii. Eye movements are determined by task1. Eye movements preceded motor actions by a fraction of a secondV. Object-Based Visual Attentiona. Location-based: moving attention from one place to anotherb. Object-based: attention being directed to one place on an objecti. Enhanced processing will apply to the entire objectc. Attention can be based on thei. Environment1. Static scenes or scenes with few objectii. Specific object1. Dynamic eventsd. Egly et al. (1994)i. Participants saw two side-by-side rectangles, followed by a target cueii. Reaction time fastest when target appeared where indicatediii. Reaction time was faster when the target appeared in the same rectangleVI. Feature Integration Theorya. Treisman and Schmidt (1982) flashed a screen and told participants to report the shown numbers and then describe the shapesi. Participants report combination of features from different stimuliii. Object features seem to exist independentlyiii. If told to focus only on the shapes, participants don’t make illusory conjunctions1. Suggests attention is required to integrate featuresb. Pre-attentive stagei. Automaticii. No effort or attentioniii. Unaware of processiv. Object analyzed into featuresc. Focused attention stagei. Attention plays key roleii. Features are combinedd. R.M.: Patient with Balint’s syndromei. Inability to focus attention on individual objectsii. High number of illusory conjunctions reportede. Feature analysis is mostly bottom-up processingf. Top-down processing influences processing when participants have an expectation of what they will seei. Top-down processing combines with feature analysis to help one perceive things accuratelyVII. Attention Processing & Attention in Social Situations: Autisma. Attention Processing Distributed Across the Cortexi. Using fMRI to detect cortical activity during a search task (Shulman et al., 1999)1. Participants viewed randomly moving dots that eventually started moving in one direction2. Respond when coherent motion is detected (RT Task)ii. Attention to an expected direction of motion caused brain activity to increase in a number of brain areasb. Attention in Social Situations: Autismi. Autism: serious developmental disorder in which one of the major symptoms is the withdrawal of contact from other people1.