Attention & Visual Search Flashcards
Dichotic Listening Tasks (Cherry, 1953)
Unattended auditory information is processed to a lower level of complexity than attended
information
- 1/3 of participants report hearing their name in the unattended channel
- Easier if voices are physically different – Bottom-up processing
Familiar Voices - Johnsrude et al, 2013
A familiar voice is easier to pay
attention to AND easier to ignore.
- We use our own experiences of
the world to help to solve the
cocktail party problem
– Top-down processing
Attention as early selection:
Broadbent’s (1958) Theory
Parallel input into sensory register
- Inputs are then filtered based on its physical characteristics
– Filtering prevents overloading of the limited capacity mechanism
– Inputs remaining in the buffer after filter are available for
later [semantic] processing
Accounts for (1) Cherry’s basic findings + (2) findings from dichotic listening task
- Unattended stimuli only undergo minimal processing before being filtered
- Filter selects an input on the basis of the most prominent
physical characteristic distinguishing the inputs
Counterpoints to Cherry’s basic findings + findings from dichotic listening tasks
Some parts of the unattended stream are processed
semantically (e.g. hearing your name within a conversation
you’re not paying attention to)
- Stimuli that people don’t report experiencing can still
change their behaviour – e.g. blindsight
Attention as late selection:
Deutsch and Deutsch (1967)
All stimuli are fully analysed
– The bottleneck occurs late,
before the response with the most relevant stimulus determining what response is made
But early sensory event-related potentials are smaller if unattended
- Bottleneck much earlier in processing + results favor Triesman’s perspective
Attention as flexible selection:
Treisman’s (1960) Leaky Filter
Unattended information is filtered after the sensory
register
– Stimulus analysis goes through a hierarchy from physical traits of the stimulus up to its meaning and beyond
– When capacity is reached, tests at the top of the hierarchy are
precluded for all but the ‘attended’ stimulus
– Precise location of the bottleneck is more flexible than in
Broadbent’s model
When is attention selection happening?
- Initially, the field considered a
distinction between early (e.g.,
Broadbent) and late (e.g., Deutsch & Deutsch) selection - In reality, probably flexible and influenced by top-down and bottom-up processes
Covert Attention: The Posner Cueing Paradigm
Sighted people can pay attention to a part of space that they aren’t
directly looking at
– Called “covert attention”
* Posner (1980) designed a paradigm to measure how that works
The Posner Cueing Paradigm: Endogenous Cues
- You choose to pay attention - top-down + goal driven
- Choosing to pay attention to a
particular part of space makes
you react faster to things that
happen in that part of space
The Posner Cueing Paradigm: Exogenous Cues
- It makes you pay attention - bottom-up + stimulus-driven
- If your attention is drawn to that
part of space without you
intending to, but only if the
something happens in that
part of space very quickly
after you shift your attention
to it
Posner’s Attentional Systems: Endogenous System
-Controlled by the individual’s intentions and expectations
- Involved when central cues are presented
- Top-down
Posner’s Attentional Systems: Exogenous System
- Automatically shifts attention
- Involved when uninformative peripheral cues are presented
- Stimuli that are salient or that differ from other stimuli are most likely to be attended
- Bottom-up
Attention as a spotlight - Posner (1980)
Endogenous attention is a limited
resource that we distribute
