Download Selective Attention: Early vs. Late Models and more Summaries Voice in PDF only on Docsity!
Attention
• Process of focusing
mental effort on
particular task or
stimulus
- Selective
- Shiftable
- Divisable
- Limited
Issues in Attention Research
• What happens to unattended information?
• What factors affect our ability to divide our
attention?
IP Psychology Selective Attention Models
Selective Attention Models
• Early Selection Models
- Attention determines nature of info that goes into working memory (short-term store)
- Selection occurs “early”, before info enters working memory
Studies of selective attention (e.g. Studies of selective attention (e.g.
Cherry, 1953)Cherry, 1953)
• subjects are presented with 2 or more
stimuli at the same time
– this is called dual-task performance
• for selective attention tasks, subjects are
instructed to attend to one input only
Dichotic listening taskDichotic listening task
• 2 simultaneous messages
– one to each ear
• each message has different meaning
– like listening to TV & radio at same time
• Subjects must shadow one ear only
– repeat the message from one ear only
• Experimenter then asks about unattended ear!
– Listeners extract only certain info from unattended
ear
• Listeners are good at detecting physical info
- could tell whether unattended channel was…
- Male vs. Female
- Speech vs. Buzzing
• Listeners are bad at detecting meaning info
- couldn’t identify any word/phrase
- couldn’t tell whether unattended channel was…
- Forward vs. Backward
- English vs. German
So what do we notice?So what do we notice?
• So, attention is
- sensitive to physical properties
- in sensitive to meaning
BroadbentBroadbent’’s Filter Model ofs Filter Model of
selective attentionselective attention
- sensory information (speech) is received in channels
- Info goes first to buffer (=temporary store)
- Then filter selects attention (chooses 1 of the channels) based on physical characteristics ( e.g. voice tone)
- This single channel is now the focus of attention
- Ignored (= unattended ) info can be recalled from the buffer but this decays rapidly! - We can only attend to one channel at a time - Switching attention between channels requires effort
BroadbentBroadbent’’s Filter Model ofs Filter Model of
selective attentionselective attention
sensory buffer
I
N
P
U
T
filtering (based on physical characteristics)
Other channel no longer processed after filtering…
short term memory
meaning extracted here on after
Broadbent’ Broadbent’s Filter Model of (early)s Filter Model of (early)
selective attentionselective attention
• Why ‘early’ model?
Physical Properties meaning
attention is selected here (early)
not here (late)
Evidence for the model Evidence for the model
• The split-span
procedure Broadbent
- 6 digits presented in 3 pairs
- 1 member of each pair simultaneously presented to each ear:
L 4 9 6
R 8 5 2
- Subjects must report what they heard, either: A) pair-by-pair 48, 95, 62 OR B) ear-by-ear 496, 852
- Participants perform better ear-by-ear
Norman’s Model
• Late Selection
- All stimuli processed to recognition
- Bottleneck after recognition just before the formulation of response
• Selection (pertinence)
based on importance
• Memory devoted to
selected inputs
Norman’s model & the data
• Cocktail Party Effect
– Name gets into STM just long enough to be
recognized
– Because important, gets extra processing
• Contextual Errors in Shadowing
– Info from both ears gets into STM
– Contextually relevant info gets extra
processing because pertinent
Deutsch & Deutsch Model ofDeutsch & Deutsch Model of
(late) selective attention(late) selective attention
• ALL stimuli are analysed for meaning but only SOME
are selected for response
- unattended message may be recognised but not pass
into awareness
- allows for subliminal perception;
- processing inputs with no conscious awareness
• Non-attended inputs are noticed only if their
relevance exceeds the relevance of the attended
channel
Deutsch & Deutsch Model of Deutsch & Deutsch Model of
(late) selective attention(late) selective attention
sensory buffer
I
N
P
U
T
No filter/No attenuation
short term memory
meaning fully extracted from both channels
Subliminally aware of meaning
Deutsch & DeutschDeutsch & Deutsch’’s Model ofs Model of
(late) selective attention(late) selective attention
• Why ‘late’ model?
Physical Properties meaning
channel is selected here (late)
not here (early)
Evidence for the model Evidence for the model
- Sophisticated meaning analysis of unattended channel - Mackay (1973). They threw stones towards the bank
… … … … … money or … … … … … river
subject shadows this
QUESTION : what does the sentence mean?
Subjects favoured the interpretation of the sentence suggested by the unattended word.
Treisman & Geffen (1967)
• Method
- Task 1: shadow message in one ear
- Task 2: tap pencil when you hear the target word “green”
• Results
- Tapping to green in shadowed ear: 87%
- Tapping to green in the other ear: 8%
Contra Late SelectionContra Late Selection
- Treisman & Riley (1969)
- Although meaning analysis is good on unattended channel, it’s BETTER on attended channel.
Shadows this. Stop when you hear a letter.
3 8 6 3 1 B …
- We’re much better at detecting the letter on the attended channel ( 7 9 4 6 1 B … )! - Therefore…the unattended channel is NOT fully processed.
Attenuator Model
- Attenuator affects “subjective loudness” - Pay attention – increase loudness - Shadowed msg “louder” than non-shadowed
- Concepts in Dictionary differ in loudness threshold - Name always low - Thresholds change w/goals
Treisman’ Treisman’ss attenuation theoryattenuation theory
- a filter attenuates unattended input rather than “turning it
off”
- so non-attended meaning does pass on, but in a weaker
form.
- because it’s weaker ( attenuated ) we can ignore it
- stimuli that are emotionally important (our name) or
biologically relevant (“sex”) are pre-set and so not
attenuated
TreismanTreisman’’ss Attenuation Model ofAttenuation Model of
selective attentionselective attention
sensory buffer
I
N
P
U
T
Attenuator
Other channel gets attenuated …
short term memory
meaning extracted here on after
Problems with the model Problems with the model
• What is an attenuated processing of
meaning???
- What does it mean to ‘partially’ work out meaning?? RABBIT
full meaning partial meaning ????
