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 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
<1
sec
10-15 sec
Broadbent’s Filter Model (1958)
• early selection model: filter before meaning generated
messages
sand
sound
filter
size
selection
attended message
fine grain sand
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
Treisman would say your
name has a low threshold
Signal strength
• Like a memory
• Contains stored words that have thresholds for being activated
• Lower thresholds mean more sensitive
own
name
Rutabuga
boat
10am
LATE-SELECTION MODELS: Mackay (1973) experiment
“They were throwing stones
at the bank.”
Attend Left
“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
TREISMAN
MACKAY
Early- or late-selection models?
Crucial variable for both: task load (cognitive resources)
FLANKER-COMPATIBILITY TASK (Green & Bavelier, 2003):
RT (ms)
EASY
C
I
RT (ms)
DIFFICULT
C
I
LOW-LOAD
RT (ms)
RT (ms)
LOW-LOAD
C
I
C
HIGH-LOAD
RT (ms)
RT (ms)
HIGH-LOAD
I
C
I
CONTROL
C
I
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:
a) happens without intention
b) 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
Strayer & Johnston (2001): driving simulation study
11am
VISUAL ATTENTION
Eye movements: windows into the mind
saccades (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 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
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
Fix
Periphery
Record from neuron that fires for peripheral light
FIX
PERIPHERY
OBJECT-BASED ATTENTION
AC=AB
RTB<RTC
RTA < RTB < RTC
OCCLUSION
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
1pm
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:
1) too short time to take in
all information
OR
1) responding takes longer
than decay time
rapid
decay…
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)
2pm
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
DECAY
– Trial 1: B F T
– Trial 2: Q S D
– Trial 3: K H J
100 …97 …94 …
96 …
104 …
PROACTIVE INTERFERENCE (PI)
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
The CODING OF INFORMATION in STM
(the way information is represented)
(auditory)
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.
Baddeley (2000): Working Memory
STM: passive simple
storage
Manipulate info during
complex cognition
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).
SPECIALIZATION in WM
Verbal, auditory…
Visual, spatial…
INTEGRATION in WM
The Phonological Loop
Three 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
2. Word-length effect
US > Welsh children digit span
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 & Phonological
Similarity 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
Point to Yes/No
Visual stimulus, visual response
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
Where in brain is short-term storage
and processing?
X
no prefrontal cortex = forgetful hungry monkey
…similar to lack of OBJECT PERMANENCE in infants
“out of sight, out of mind”
<8 month old:
occluded object gone out of existence
Reason: prefrontal cortex not
developed
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)