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• 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 onemessage• Didn’t retain much from the ‘unattended’message - even when repeated 35xBroadbent’s Filter Model (1958)• human as information processor

cocktail-party phenomenon

< 1 sec10-15 sec

Broadbent’s Filter Model (1958)• early selection model: filter before meaning generated

sand

fine grain sand

size selection

messages

attended message

soundfilter

voicepitchspeedaccent

meaning

Broadbent (1958): split-scan experiment• Cond-1 = 65% accuracy• Cond-2 = 20% accuracy

CONDITION 1: repeat in any order

CONDITION 2: repeat each pair, as presented

Typical answers: MRW; HSP

Typical answers: MH; RS; WP

Assumption: -ears as separate channels-switch is costly

Flaws in the Filter Model(Gray & Wedderburn, 1960)

Moray (1959): own name heard in unattended ear is remembered

Meaning trumps filtering & switching

Explanation:No switching, because no

channelsMeaning processed before

filtering

Only attended message should get through!

“LEAKY FILTER” MODEL (ATTENUATION THEORY): Treisman (1964)

AttenuatorAnalyze incoming message in terms of:• Physical characteristics• Language• MeaningJust 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

Treisman would say your name has a low threshold

ownnam

e

Sig

nal st

rength

Rutabuga boat

10am

LATE-SELECTION MODELS: Mackay (1973) experiment

Attend Left

“They were throwing stones at the bank.”

“river” or “money”

(biasing words)

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?

BROADBENT

MACKAY

TREISMAN

Early- or late-selection models?Crucial variable for both: task load (cognitive resources)

FLANKER-COMPATIBILITY TASK (Green & Bavelier, 2003):

RT (

ms)

C I

EASY

RT (

ms)

C I

DIFFICULT

RT (

ms)

C I

RT (

ms)

C I

LOW-LOAD

HIGH-LOAD

CONTROL

RT (

ms)

C I

RT (

ms)

C I

LOW-LOAD

HIGH-LOAD

VIDEO GAME PLAYERS

Lavie (2005): EARLY-SELECTION MODELS use HIGH-LOAD tasksLATE-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

becomes automatic

Schneider & Shiffrin (1977):

AUTOMATIC:a) happens without intentionb) 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 inattention22% of crashes due to cell phone usage

Strayer & Johnston (2001): driving simulation study

11am

VISUAL ATTENTION

Eye movements: windows into the mindsaccades (rapid movements) fixations (short pauses; 3/sec)

Eye tracker (noninvasive)

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 ACTIONSTask goals guide fixations to land on

objects relevant to the task ORDER of eye movements not the same for

everybody

Inattentional blindness: looking, but not seeing (Mack & Rock,1998)

Attending without looking:

Triangle not recognized

PRECUING: attending to a location without moving the eyes (Posner, Snyder & Davidson, 1980)

Reaction time: predicted location < unexpected location

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

FIX PERIPHERY

AC=ABRTB<RTC

OBJECT-BASED ATTENTION

RTA < RTB < RTC

OCCLUSION

static scene,moving spotlightAttention is independent of objects

moving scene,moving spotlightAttention is connected to object

Location-based

CAN EYE MOVEMENTS DIAGNOSE ATTENTION DISORDER?

Typically developing viewersTypically developing viewers

Autistic viewersAutistic viewers

(Klin, Jones, Schultz & Volkmar, 2003)

Typically developing viewersTypically developing viewersAutistic viewersAutistic viewers

1pm

The man with a 30 second memory:http://www.youtube.com/watch?v=wDNDRDJy-vo&feature=related

-can not form new memories1-2 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 presentation4–5 letters remembered

rapid decay…

TWO OPTIONS:1) too short time to take in

all information OR

1) responding takes longerthan decay time

high capacity (82%), rapid decay (~1sec)

responding takes longerthan decay time

Functions of Sensory Memory:

– Collection of information to be processed

– Holding information while processing

– Filling in blanks of intermittent stimulation (movies)

2pm

The Duration of STMPeterson & Peterson (1959):

Read 3 letters, followed by a numberCount back by 3sRecall 3 letters after 3sec or 18sec

DECAY PROACTIVE INTERFERENCE (PI)

– Trial 1: B F T 100 …97 …94 … – Trial 2: Q S D 96 …– Trial 3: K H J 104 …

The Capacity of STM (how much information can be stored?)

Digit span: 5-8 ITEMS 5-8 CHUNKSWhat’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):

3pm

Complexity: STM as many distinct mechanisms.Demonstration: Reading text and remembering numbers.

STM: passive simple storage

Manipulate info during complex cognition

Baddeley (2000): Working Memory

How to manipulate incoming info?

Baddeley (2000):

Working Memory is a limited capacity system for temporary storage and manipulation of information for complex tasks (e.g., comprehension, learning, reasoning).

Verbal, auditory… Visual, spatial…

SPECIALIZATION in WM

INTEGRATION in WM

The Phonological LoopThree phenomena suggest a specialized sub-system:1. Phonological Similarity Effect– ‘mac, can, cap, map’ harder than ‘pen, pay, cow, rig’– Conrad (1964): Misidentifications phonologically similar

US > Welsh children digit span

2. Word-length effect

3. Articulatory suppression (dual tasking) can diminish the word-length effect

Word-length effect occurs only if rehearsal allowed:memorization is a learning process

Articulatory Suppression & PhonologicalSimilarity Effect

Conrad (1964): control condition

INTERACTIONS BETWEEN PHONOLOGICAL LOOP AND SKETCH PAD

VERBAL stimulus, VERBAL response

VERBAL stimulus, SPATIAL response

Say Yes/No

Visual stimulus, verbal response

Visual stimulus, visual response

Point to Yes/No

4pm

Effects support idea of two specialized subcomponents:Phonological Loop and Visuospatial sketch pad

Working Memory can handle different information

But…

overloads when similar type of info presented simultaneously

CENTRAL EXECUTIVE: controls suppression of irrelevant information

Gazzaley et al. (2005)

Articulatory suppression has minor effect: decrease memory span from 7 to 5

no prefrontal cortex = forgetful hungry monkey

XWhere in brain is short-term storageand processing?

“out of sight, out of mind”

<8 month old:occluded object gone out of existence

Reason: prefrontal cortex not developed

…similar to lack of OBJECT PERMANENCE in infants

Funahashi et al. (1989)

American Sign Langauge should be visual visuo-spatial sketch pad

But it shows features of phonological loop processing:

Word-length effect: words with longer gestures harder to remember

Phonological similarity effect: words expressed by similar gestures harder to remember

CONCLUSION: Phonological loop activated by language irrespective of modality (sound or gesture)