Cognitive approaches:
Information processing,
with the computer as a model
Too much information –
How do we select what’s relevant?
Bottleneck metaphor
Read the bold print.
Somewhere Among hidden the in most the
spectacular Rocky Mountains cognitive
near abilities Central City is Colorado the
an ability old to miner select hid one a
message box from of another. gold. We
Although do several this hundred by people
focusing have our looked attention for on
it, certain they cues have such not as
found type it style.
What about the old miner?
Change detection:
Role of attention allocation
Cognitive psychology:
• Something between stimulus and
response – hidden, covert…
• Donders’ reaction time experiments
Cognitive psychology:
• Something between stimulus and
response – hidden, covert…
• Donders’ reaction time experiments
• Thinking takes time
• Separable components: perceptual
discrimination, motor selection, etc.
A modern version of Donders’ (1868) reaction time experiment. (a) the simple
reaction-time task; and (b) the choice reaction-time task. For the simple time
reaction text, the participant pushes the J key when the light goes on. For the
choice reaction time test the participant pushes the J key if the left light goes on,
and the K key if the right light goes on. The purpose of the Donders experiment
was to determine the time it took to decide which key to press for the choice
reaction time test.
Sequence of events between presentation of the stimulus and the behavioral
response, in Donders’ experiment. The dashed line indicates that Donders
measured reaction time, the time between presentation of the light and the
participant’s response. (a) simple reaction-time task; (b) choice reaction-time
task.
Anne Treisman: two types of search
Feature-integration theory of attention
Pop-out: Parallel (“easy”) search
• Singleton target: differs from a homogeneous set of
distracters in only one visual dimension
• Example: Green item among reds
• Search time is independent of the number of distracters
• You can make an immediate decision
• Both for deciding “yes” or “no”
• “Automatic”
Scanning: Serial (“difficult”) search
• Conjunction target: cannot be distinguished from the
distracters on the basis of a single feature
• Requires “glueing together”
• Example: Green square among green circles and red
squares
• Search time depends on the number of distracters
• You have to check each item one-by-one
• Saying “target present” is usually faster than saying
“target absent”: self-terminating search
• “Attentive”, “Voluntary”
Pop-out at a few months; serial search much later
Pop-out becomes challenged before serial search; Effects of training and
expertise persist much better…