what is the cocktail party phenomenon?
the process of tracking one conversation in the face of distraction from other conversation
- studied by shadowing
what is shadowing? what did Cherry (1953) find using this method?
listening to 2 different messages (dichotic presentation) but only repeating one back
Cherry:
- P’s were successful in doing this, although it requires a lot of concentration
- P’s also noticed physical/sensory changes in the unattended message (e.g. speaker changing from male to female)
- Did not notice semantic changes (e.g. when messages switched from English to German or was played backwards)
what are 3 factors that help to selectively attend to only one message?
- Distinctive sensory characteristics of the target’s speech (e.g. high vs low pitch, pacing & rhythmicity)
- Sound intensity (loudness)
- Location of the sound source
filter vs bottleneck theories of attention
Filter = blocks some of the info going though = selects only a part of the total info to pass onto next stage
Bottleneck = slows down info passing though
- only the attenuation model (Treisman)
Broadbent’s model of attention
we filter info right after we notice it at the sensory level
- Multiple channels of sensory input reach an attentional filter - channels can be distinguished by characteristics
- Filter permits only 1 channel to proceed & reach the processes of perception
- Other stimuli are filtered out at the sensory level = may never reach level of perception
Selective filter model of attention (Moray)
the selective attention filter blocks out most info at the sensory level but some personally imp messages break through
- Moray found that even when ignoring most high-level aspects of an unattended message, p’s still frequently recognize their names in an unattended ear
- Suggested that this is bcuz messages that are of high importance to a person break through the filter
Attenuation model of attention (Treisman)
selective attention involves a later filtering mechanism - instead of blocking stimuli out, the filter weakens the strength of other stimuli
- When the stimuli reach us, we analyze them at a low level for target properties - if the stimuli possess those target properties, its passed to the next stage, if not a weakened version is passed
- Next we perceptually analyze the meaning & relevance of the stimuli - so even a message from the unattended ear can come into consciousness & influence our subsequent actions if its meaningful
Late-filter model of attention (Deutsch & Deutsch)
Suggested that stimuli are only filtered out after their physical & semantic properties have been analyzed
Later filtering = allows people to recognize the sound of their own name or a translation of attended input (bilinguals)
A synthesis of early-filter & late-filter models of attention (Neisser)
Neisser synthesized the early & late filter models & proposed there are 2 processes governing attention:
Pre-attentive processes: automatic processes that are rapid & occur in parallel - can be used to notice only the physical sensory characteristics of the unattended message
Attentive, controlled processes: occur later - are excited serially & consume time & attentional resources (like working memory)
What is inattentional blindness?
the failure to notice fully visible, but unexpected events when attention is focused elsewhere
effectively filter other info from awareness - we perceive only what receives the focus of our cog efforts
Neisser’s attentional blindness experiments
Og experiment:
- P’s watched a video of 2 distinct but partially transparent & overlapping events
- P’s asked to monitor 1 of the events by counting number of times the actors performed the action
- Often failed to notice unexpected events in the ignored video
Variation:
- P’s watched a video of 2 teams of players (white shirts & black shirts)
- Asked to press a key whenever the white played successfully passed a ball, but ignore black players
- Halfway through the video a person wearing a raincoat & umbrella walked past
- P’s often missed this
Factors that effect noticing
- The greater the demands on attention, the less likely we are to notice objects falling outside our attention
- The more like the ignored elements of a scene, the less likely we are to notice
- The more distracted we are, the less likely we are to be aware of our surroundings - under conditions of distraction, we develop tunnel vision
How does WM effect noticing?
Some studies suggest people who have a greater working WM capacity = more likely to notice unexpected objects - other studies find no such relationship
Theoretical explanations for both:
- People w greater WM capacity = more resources available = should be more likely to notice
- But people w greater WM capacity = tend to be better at maintaining focus on 1 task = should be less likely to notice
What is the attentional blink?
the impaired ability to identify the second of 2 visual targets presented in close succession
what is change blindness?
failure to see something different in a display - undergoes change without being noticed
e.g. curtain changing from yellow to orange
attentional blink experiment - method
(olivers & nieuwenhuis, 2005)
- 66 randomly assigned subjects
- Series of letters presented rapidly on display, including 2 target digits (T1-T2)
- Must report this at the end of the trial
attentional blink experiment - conditions
(olivers & nieuwenhuis, 2005)
- Standard condition: instructed to concentrate on the task & report as many digits as possible
- Free association condition: asked to think about their holiday or their shopping plans while doing the task
- Listen-to-music condition: presented w a continuous rhythmic tune. One group asked to just listen to the beat, other group asked to listen for a yell
- Reward condition: paid according to performance
attentional blink experiment - results
(olivers & nieuwenhuis, 2005)
Detection of T1 was poor for lag 1 in all groups bcuz lags were in close temporal proximity & p’s would enter T2 first
- Music group performed the best
Standard & reward group: T2 suffered considerably at most lags, except lag 1 (lag 1 sparing)
Free association group: T2 detection was sig better
Music group: T2 detection very high = attentional blink disappeared
attentional blink experiment - conclusion
(olivers & nieuwenhuis, 2005)
- perf on an attentionally demanding visual detection task may improve when the task is accompanied by task-irrelevant mental activity
- under conditions of rapid visual presentation target detection may benefit from a diffusion of attention
what is selective attention?
processes that allow an individual to select & focus on particular input for further processing while suppressing irrelevant or distracting info
what is inattentional deafness?
people fail to notice an unexpected sound or voice when attention is devoted to other aspects of a scene
