Cognitive approaches: Information processing, with the computer as a model

Too much information – How do we select what’s relevant? Bottleneck metaphor

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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…