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9am. Attention • Difficult to define - like nailing jello to the wall. • Goldstein defines it as: • the process of concentrating on specific features of: • the environment • thoughts or activities • what then is concentrating? • focusing attention. Some Examples
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Attention • Difficult to define - like nailing jello to the wall. • Goldstein defines it as: • the process of concentrating on specific features of: • the environment • thoughts or activities • what then is concentrating? • focusing attention Some Examples • Dodging kids that run out into the street • Reading and listening to music • Daydreaming and not hearing someone talking to you (a.k.a. “spacing–out”) Attention is involved in: • Perception • Memory • Language • Problem solving
Selective Attention • Loosely defined: the ability to focus on only one thing. • For example, spacing out – staring at the TV and not hearing the phone ring. Dichotic Listening Tasks (Cherry, 1953) • 2 messages presented - one in each ear • Shadowing: ‘attend to’ and repeat one message • Didn’t retain much from the ‘unattended’ message - even when repeated 35x cocktail-party phenomenon Broadbent’s Filter Model (1958) • human as information processor 10-15 sec < 1 sec
messages sand sound filter size selection attended message fine grain sand Broadbent’s Filter Model (1958) • early selection model: filter before meaning generated voice pitch speed accent meaning
Broadbent (1958): split-scan experiment • Cond-1 = 65% accuracy • Cond-2 = 20% accuracy CONDITION 1: repeat in any order Typical answers: MRW; HSP CONDITION 2: repeat each pair, as presented Typical answers: MH; RS; WP Assumption: -ears as separate channels -switch is costly
Flaws in the Filter Model (Gray & Wedderburn, 1960) Meaning trumps filtering & switching Explanation: No switching, because no channels Meaning processed before filtering Moray (1959): own name heard in unattended ear is remembered
Only attended message should get through! “LEAKY FILTER” MODEL (ATTENUATION THEORY): Treisman (1964)
Attenuator Analyze incoming message in terms of: • Physical characteristics • Language • Meaning Just enough processing to distinguish different incoming messages
The Dictionary Unit • Like a memory • Contains stored words that have thresholds for being activated • Lower thresholds mean more sensitive Signal strength own name Rutabuga boat Treisman would say your name has a low threshold
“river” or “money” (biasing words) “They were throwing stones at the bank.” Attend Left LATE-SELECTION MODELS: Mackay (1973) experiment TEST: “They threw stones toward the side of the river yesterday.” “They threw stones at the savings and loan association building yesterday.” Which sentence is closest in meaning to the attended sentence?
TREISMAN BROADBENT MACKAY
EASY RT (ms) C I DIFFICULT RT (ms) C I Early- or late-selection models? Crucial variable for both: task load (cognitive resources) FLANKER-COMPATIBILITY TASK (Green & Bavelier, 2003):
LOW-LOAD LOW-LOAD RT (ms) RT (ms) C I HIGH-LOAD HIGH-LOAD C I RT (ms) RT (ms) C I C I CONTROL VIDEO GAME PLAYERS
Lavie (2005): EARLY-SELECTION MODELS use HIGH-LOAD tasks LATE-SELECTION MODELS use LOW-LOAD tasks DIVIDED ATTENTION Spelke (1976): simultaneously read and take dictation DAY 1: can do both separately; not simultanously After 85 hours of practice: can do both at the same time
Schneider & Shiffrin (1977): -detecting ‘targets’ in rapidly presented frames -divide attention between memorization and visual search
Schneider & Shiffrin (1977): becomes automatic • AUTOMATIC: • happens without intention • few cognitive resources needed
Schneider & Shiffrin (1977): -automatic processing not possible for difficult tasks -both target & distractor are letters -never becomes automatic, remains controlled processing -everyday examples of divided attention?
DRIVING AND INATTENTION 80% of crashes caused by as little as 3 sec inattention 22% of crashes due to cell phone usage
VISUAL ATTENTION Eye movements: windows into the mind saccades (rapid movements) fixations (short pauses; 3/sec)
Where do we look? • Areas of high STIMULUS SALIENCE (bottom-up process) SALIENCY MAP (Parkhurst, Law & Niebur, 2003) SCENE SCHEMA: “office schema” top-down process
ATTENTION DURING ACTIONS Task goals guide fixations to land on objects relevant to the task ORDER of eye movements not the same for everybody
Attending without looking: Inattentional blindness: looking, but not seeing (Mack & Rock,1998) Triangle not recognized
PRECUING: attending to a location without moving the eyes (Posner, Snyder & Davidson, 1980) Reaction time: predicted location < unexpected location
Fix Periphery PHYSIOLOGICAL EVIDENCE FOR PRECUING (Colby, Duhamel & Goldberg, 1995) • Light at fixation point and in the periphery • Trained to always look at the fixation point • “Fixation only” condition: release handle when fixation light dimmed • “Fixation and attention” condition: release handle when peripheral light dims Record from neuron that fires for peripheral light
FIX PERIPHERY
OCCLUSION OBJECT-BASED ATTENTION AC=AB RTB<RTC • RTA < RTB < RTC
Location-based static scene, moving spotlight Attention is independent of objects moving scene, moving spotlight Attention is connected to object
CAN EYE MOVEMENTS DIAGNOSE ATTENTION DISORDER? (Klin, Jones, Schultz & Volkmar, 2003) Autistic viewers Typically developing viewers
Autistic viewers Typically developing viewers
The man with a 30 second memory: http://www.youtube.com/watch?v=wDNDRDJy-vo&feature=related -can not form new memories 1-2 minute “bubble” Boundaries: Knowledge vs. memory? Definition: retain, retrieve, and use information about stimuli and skills after the original information is no longer present. Atkinson & Shiffrin (1968) msec-sec 15-30sec years
Sensory Memory -brief retention of the effects of sensory stimulation. The Sparkler’s Trail (persistence of vision)
How much information can be stored in sensory memory? (Sperling, 1960) 50ms presentation 4–5 letters remembered
TWO OPTIONS: • too short time to take in all information • OR • responding takes longer • than decay time rapiddecay…
responding takes longer than decay time high capacity (82%), rapid decay (~1sec)
Functions of Sensory Memory: – Collection of information to be processed – Holding information while processing – Filling in blanks of intermittent stimulation (movies)
The Duration of STM Peterson & Peterson (1959): Read 3 letters, followed by a number Count back by 3s Recall 3 letters after 3sec or 18sec – Trial 1: B F T 100 …97 …94 … – Trial 2: Q S D 96 … – Trial 3: K H J 104 … PROACTIVE INTERFERENCE (PI) DECAY
The Capacity of STM (how much information can be stored?) • Digit span: 5-8 ITEMS 5-8 CHUNKS • What’s an item: letter? word? phrase? • Chase & Simon (1973): show chess setup for 5 sec Master knows how to “chunk”, without necessarily having a superior STM
(auditory) The CODING OF INFORMATION in STM (the way information is represented) • AUDITORY CODING (Conrad, 1964): • – saw letters briefly (e.g., FHSGZ…) • asked to write down letters in the order they were presented • when errors occur, they are based on similar sound (F seen as S or X), rather than visual similarity (F seen as E). Sound > Vision
The CODING OF INFORMATION in STM VISUAL CODING (Zhang & Simon, 1985):
The CODING OF INFORMATION in STM SEMANTIC CODING (Wickens, 1976):
Complexity: STM as many distinct mechanisms. Demonstration: Reading text and remembering numbers. Baddeley (2000): Working Memory STM: passive simple storage Manipulate info during complex cognition