Attention: what happens to the information we ignore
Early vs Late selection
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Early selection processes both info, but when it reaches bottle neck then only one
things meaning gets processed
Late selection
Cocktail Party Effect
Colin Cherry, 1953
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You can overhear other people’s conversations
Dichotic listening task
Colin Cherry, 1953
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Present different messages to each ear
Subjects attended one ear and ignored the other
Repeat attended message out loud – shadowing
Participants shadowed attended message easily
When asked about the unattended message, physical characteristics like sec of
voice, changes of pitch are usually reported
Rarely noticed when unattendrd message was in foreign language or reversed
speech
No content remembered, even when same word 35 times
Broadbent’s filter theory 1968
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Early-selection model
Filtering occurs before incoming
stimuli are analysed to semantic level
Surface features but not meaning
analysed
Sensory store: holds incoming info for short period of time
Filter: analyses message based on physical characteristics like tone of voice, pitch, location
of stimulus (which ear)
Detector: info processed to determine meaning
Short-term memory: holds info for general processing
Problems with early selection
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Moray (1959) - Subjects heard their name in the unattended stream
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Treisman (1960) Bilinguals influenced by unattended stream if it is in second
language
Gray & Weddeburn (1960):
Response should have been “Dear 7 Jane”
Subjects said “Dear Aunt Jane”
Said a sentence that made more logical sense to them
Treisman’s attenuation model
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Still an early-selection theory
Key modification to filter theory
You don’t lose info completely, its just reduced
Unattended messages attenuated (reduced) rather than lost completely
How does this explain breakthrough?
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Words need to meet a certain threshold of
signal strength to be detected
Thresholds for certain words lowered
So more easily detected
Eg. own name or words primed by context
Late selection models
Deutsch and Deutsch (1963), Kahneman (1973), Duncan (1980)
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Both attended and ignored inputs processed to stage of semantic (meaning) analysis
Selection:
Takes place at higher stage of processing
Based on analysis of which input is most important/demands a response
Can explain MacKay (1973) Dichotic listening:
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Attended stream: ambiguous sentence
Unattended stream: biasing word
If “money”, “bank” was more likely interpreted as financial institution
Response competition interference )eg. Eriksen & Eriksen, 1974
Incongruent distractor in irrelevant location slows RTs
Distractor identity processed
Negative priming
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Responses to previously ignored stimuli are slowed
Task: Categorise red stimuli, ignore green.
Result: Responses to word slowed when preceded by semantically related IGNORED
picture
Suggests ignored stimuli is semantically categorised and inhibited
Lavie’s Load Theory
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Both early and late selection are possible
Stage of selection depends on availability of perceptual capacity
Which depends on perceptual demands or load of task stimuli
Perceptual capacity is limited
Takss with high perceptual load exhaust capacity
Irrelevant distractors are filtered or attenuated at early, perceptual stage: Early
selection
Tasks with low perceptual load leave spare capacity
Irrelevant distractors are processed: Late selection
Evidence supporting
Behavioural measures of distraction
- Response competition effects found under low load
- Reduced or eliminated under high load
Inattentional Blindness
Cartwright Finch & Lavie
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6 trials
Unexpected stimulus on
final trial
Neuroimaging evidence
Schwartz et al., 2005
Task:
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Low load: detect red cross
High load: detect conjunction eg. yellow upright
Ignore background
High perceptual load reduces visual cortex response to
background
High perceptual load reduces amygdala response to fearful faces (Bishop et al., 2007)
Implications for individual differences
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Efficiency of selective attention depends on availability of perceptual capacity
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Capacity differences associated with:
Autism
Age (children and older adults have reduced capacity)
Video game experience
• Early Selection theories:
– Irrelevant information is filtered, or attenuated, at perceptual stage of processing.
– Semantic information not processed
• Late selection theories:
– All stimuli is processed to the point of meaning
– Selection takes place at later stage of processing and may involve inhibition
• Load Theory:
– Both early and late selection are possible depending on perceptual load of task stimuli