Lecture 4 - Selective Attention Flashcards
What did Cherry (1953) do
Cherry (1953)
- Dichotic listening
- ‘Shadow’ the message to one ear and
ignore message to other ear
What did Cherry (1953) find
- After shadowing, pps were asked about semantic content of ‘unattended’ message
- Didn’t notice if language changed from English to German
-or if speech was reversed - Gender of speaker and if the message contained speech or nonspeech sounds was remembered
What are the conclusions of Cherry (1953)
- People process ‘unattended’ information ONLY to level of physical features
- No semantic information is available from ‘unattended’ message
What is the early selection model
Broadbent (1958)
- Filtering occurs at early stage of analysis (before meaning)
- Brain filters out any message without appropriate ‘physical’ characteristics
Arrows represent information passing through different stages
What did Moray (1959) find in his version of a dichotic listening task
Used 2 alternative forced choice procedure (2AFC)
- Even a word repeated 35 times in unattended ear wasn’t recognised
- BUT if that word was pp’s own name, they did report hearing it (only for 33% of pps)
2AFC means that instead of asking an open ended q 2 options are presented and pps are asked to pick which is right
What did Gray & Wedderburn (1960) find in their version of a dichotic listening task
Split-span experiment
- 40% reported by ear
- 60% reported by meaning
Conlusion is the ‘unattended’ message was processed for content after all (by at least 60% of pps)
What is the late selection model
Deutsch and Deutsch (1963)
- All inputs encoded & analysed in
parallel to semantic level - Selective filtering only occurs at conscious awareness
Arrows represent information passing through different stages
What is evidence in support of the late selection model
Deutsch and Deutsch (1963)
Corteen & Dunn (1974)
Training: City names paired w/ electric shock
-Subjects sweat when they hear any
city name
What was the procedure of Corteen & Dunn (1974)
- Training: City names paired w/ electric shock
-Subjects sweat when they hear any city name - Test: Shadow one ear and ignore other
-Press a button if you hear a city name in either ear
What is the measures of Corteen & Dunn (1974)
- Test: Shadow one ear and ignore other
-Press a button if you hear a city name in either ear - Measures: galvanic skin responses (GSRs) & button presses to city names.
What is a galvanic skin response (GSR)
Measures the skin’s electrical changes
irt sweat gland activity in fingers & palms
What did Corteen & Dunn (1974) find
- 42% of city names in ‘unattended’ ear elicit a GSR (30% for non shock associated city names)
- On only 2% of these trials did the pp make a button press response
- Different measures of awareness of ‘unattended’ stimuli give different results
What is the attenuator model
Treisman (1964)
- Unattended information is ‘attenuated’
-not filtered out completely - All inputs are analysed for meaning
-but some signals are now weaker than others
What is the dictionary analysis filter in the attenuator model
Treisman (1964)
- The dictionary analysis units act as the final filter
- Different words have different trigger thresholds (e.g. your name has a low threshold)
words are attenuated based on significance
-words with little significance have high thresholds and get stopped by this filter
vice versa
What are the advantages of the attenuator model
Treisman (1964)
- Allows for nuance
- Builds upon the foundation of previous models
- Aims to explain why some words pass through & others don’t
-which other models fail to explain - Thresholds of certain words can change over time as well
-taking into account the “dear aunt jane” / “1 2 3” example, the context of the prior words lowers the threshold for the following ones, which explains why those words are more easily detected
What did Neisser & Becklen (1975) find
- Superimposed 2 videos onto each other
- PPs monitored one video for targets left pps unaware of events in the unmonitored video
- People shocked to hear this when told about facts they missed in the unattended vid
What did Simons & Chabris (1999) find
Gorilla basketball video
- Around 50% of ppl fail to notice the gorilla when attending white T-shirt team
- More likely to notice if carrying out an ‘easy’ task than if carrying out a ‘hard’ task
- More likely to notice gorilla if attending black T-shirt team
What did Dalton & Fraenkel (2012) find
70% of ppl fail to notice the auditory gorilla man “I’m a gorilla” repeated for 19s when attending to the women’s conversation
- 90% notice him when attending to the men’s conversation
- All pps (but 1) notice him in the full attention control
What is a weakness of the above visual studies which otherwise seem to support the early selection model
May be dependent on eye movement. Rather than attention
Eye movements related to attended events might reduce acuity for unattended events
What did Rock & Gutman (1981) find
- 2 shapes superimposed on each other, yellow & pink
- Pps asked to attend to shapes in one colour and rate their pleasant/unpleasantness
- Afterwards pps unable to recognise shapes in ‘unattended’ colour (even if shapes are familiar, and asked only 1 second after shown)
What evidence is there that visual tasks DON’T follow the early selection model
- Negative priming (Tipper, 1985)
- 5 primes in order of increasing reaction time to probe (dog)
- Attended repetition
- Attended semantic
- Neutral
- Ignored semantic
- Ignored repetition
What is another piece of evidence in support of Broadbent’s early selection model
Lachter, Forster & Ruthruff (2004)
- Attention possible allocated to the supposedly unattended stream at times
- They term this process ‘slippage’
mainly counterpoint for auditory tasks
What can explain the mixed findings regarding selection models
Shulman (1990) highlights:
- Over-extrapolation of findings, auditory dichotomy listening might not be adequate to form a whole theory on human attention around it
- Problems with direct report, sometimes pps register things unconsciously but can’t articulate it, GSR, -ve priming
What is perceptual load theory procedure Lavie (1995)
Ask pps to find ‘N’ or ‘X’ amongst letters + w/ a distractor present
Found RT ^ w/ incongruent distractor in low load, this supports late selection model, since diff between both distractor variations
both RT lower than high load condition
same RT in high load
this supports early selection model, since no diff between incongruent + congruent in high load
What is the conclusions of perceptual load theory
- Perceptual system has a limited
capacity - All stimuli are processed automatically
until capacity is reached
ends the early + late selection model debate
High perceptual load theory vs low perceptual load theory according to Lavie (1995)
This is what Selective attention depends on!
- High perceptual load in relevant task leaves no spare capacity for processing task-irrelevant stimuli
- Low perceptual load leaves spare capacity which “spills over” involuntarily to the processing of task-irrelevant stimuli
What is perceptual load defined by
Rees et al. (1997)
more perceptual load is
“increasing the number of items in a display
or increasing the processing requirement for the same number of items”
