Lecture 9 Flashcards
What is dichotic listening?
an early paradigm used to
study selective attention
Describe the process of dichotic listening
One message is presented to the left ear and
another to the right ear and participants are asked to
shadow one message while ignoring the other
What is the cocktail party effect?
The ability to focus on one auditory stimulus while
filtering out others
Describe Broadbent’s filter model
Messages –> Sensory memory –> Filter –> Detector –> memory
What is binding?
process by which features (colour, form, etc.) are combined to create
our perception of coherent objects
What is a binding problem?
features of
objects are processed separately in
different areas of the brain, yet
somehow get integrated to form
coherent representations which we
perceive as singular objects… how
does this occur?
Describe the Treisman and Schmidt study
Four coloured shapes and two numbers flashed onscreen very briefly (~200
ms), followed by a mask
- Task was to report numbers first, then colour/shape combinations of other
stimuli
Describe illusory conjunctions
Illusory conjunctions were common, in which properties from different
objects are erroneously bound together and perceived as being contained
within the same object
What is feature integration theory?
proposes that binding occurs in two distinct
stages:
1. Preattentive stage: object features are extracted and processed (and
proceeds automatically, no effort or attention required)
2. Focused attention stage: extracted features are bound together to form
coherent perception (attention plays a key role, and this is the point at which
binding errors typically occur)
give an example of a feature search
Try to find the
horizontal line as
quickly as possible
- This can be referred
to as a feature
search
Give an example of a conjunction search
Now try to find the
horizontal green line
as quickly as possible
- This can be referred
to as a conjunction
search
Describe feature search speed
The speed of a feature search is
typically not sensitive to (i.e. affected
by) the number of distractors (green
line on graph at left)
* Because no binding has to take
place there is a pop-out effect, in
which the target is almost
immediately perceived
Describe conjunction search speed
This can be explained on account of
the necessity to deploy focussed
attention to each item to bind their
features when searching for the
target
Describe Posner study
Participants begin trial looking at fixation
point
* Precueing accomplished with an arrow
indicating which side of screen target was
likely to appear
* Target location was either consistent (valid
trial: 80% of trials) or inconsistent (invalid
trial: 20% of trials) with the cue
What is spatial attention?
attention that has been bound to specific locations
What is attentional spotlight?
The ‘attentional spotlight’ metaphor has sometimes been used in this
context
Describe the Egly study
Participants presented with two rectangles
* Target could appear in one of four places (either end of either rectangle)
- Cue signals where target likely to appear
- Task was to push button as quickly as possible
once target detected
fastest reaction times occurred when the target appeared
at the cued location (as expected)…
Describe same object advantage
Interpreted as “enhancement” effect
that spreads through non-target within
the target rectangle
Describe Malcolm and Shomstein study
Task was to find/fixate the apple (the
cue), then look for the lightbulb (the
target, which automatically appeared
317 ms after the apple had been
initially fixated), then identify whether a
letter appearing on the lightbulb is a T
or L
* Target could appear on same or
different chair than the cue
Participants were faster to respond to targets that appeared on the same
chair as the cue
- Demonstrates same-object advantage in real-world scene
