© 2001 Dr. Laura Snodgrass, Ph.D.1 Attention Determines which codes get processing Often associated...

© 2001 Dr. Laura Snodgrass, Ph.D. 1

Attention

• Determines which codes get processing

• Often associated with conscious awareness

• A continuum that varies with the amount of conscious awareness and effort

conscious decision processes unconscious monitoring (require attention and effort) (effortless)


Theories of Attention

• All theories agree on limited capacity and selectivity

• Disagree on location of limits and how selection is done

• All share the basic information processing premises– disagree on order of information flow


Basic Information Processing

Stimulus

Sensory Register

STM (working Memory)

LTM

Response


Dichotic Listening

• Common research technique to investigate selective attention

• One message is presented to one ear and a different message is presented to the other ear

• Subjects are instructed to shadow one ear– shadow = repeat out loud what they hear

• What happens to your memory for the information?


Early Selection Model

Sensory filter theory (Broadbent)Stimulus

Sensory Register

Sensory FILTER

STM limited capacity LTM

Response


Early Selection

• All information enters the sensory register

• FILTER selects based on physical characteristics– Only what passes through filter has access to LTM– No selection based on meaning because meaning

is stored in LTM


Experiments that support early selection

• Cherry (53) - dichotic listening– no memory for information in unattended ear– not notice change from English to German

• Neisser & Becklen (75) - superimposed video images– ballgame and handslap– attend to one and not notice bizarre events in the other


Contradictory Results

• Cocktail Party Phenomenon– own name is recognized in unattended ear

• Treisman– subjects switch shadow to follow message when

message is switched to “unattended” ear– only is message continues in other ear

• Both results indicate knowledge of meaning from the unattended ear


Attenuator Model

• Treisman (64)– How can subjects be influenced by the meaning in

the unattended ear?– Unattended information is only dampened (attenuated)

not filtered completely– Significant information gets through the filter


Late Selection Model

Norman (68)Stimulus

Sensory Register

LTM

Selection based on pertinence orsaliency mechanism

STM

Response


Late selection

• All incoming information activates LTM

• Saliency– expectancy or constant monitor for some stimuli

• Pertinence– important to you

• Information with highest activation is selected for response


Comparison

• Differences– location of filter (before or after LTM)

– basis for selection

• Similarity– no permanent memory for unattended (not selected)

information


Experiments supporting late selection

• Lewis (73)

– unattended information increases RT to attended IF semantically related

• e.g. RT to animal names

• Mackay (73)

– unattended disambiguate the meaning of attended

• “they threw money towards the bank” in one ear

• “money” or “river” in unattended influences interpretation

• GSR study

– reaction to words associated with shock even if presented in unattended ear


Capacity Theory

• Selective attention as the allocation of capacity, NOT a block or filter

• Attend to more than one thing at a time– divide up attention

• Shiffrin and Schneider (77)– finite capacity to be divided– attention = process of allocating resources to various

inputs– divide attention among automatic and controlled

processes


Automatic and Controlled Processes

• Automatic– not use limited capacity

mechanism

– not use working memory

– not interfere with other auto or control processes

– occur in parallel

– effortless

– not interruptible- once initiated continue to completion without control (e.g. Stroop effect)

– does NOT lead to learning (no LTM)

• Controlled– use limited capacity

mechanism– limited # can operate at once– usually sequential– necessary for learning (LTM)– two types

• conscious and accessible

• veiled, unconscious, e.g. a memory search


Research on the capacity theory

• Distinguishing automatic and controlled processes– dual task - if performance decreases then both must

be controlled; if no decrease then one or both automatic (or not exceed capacity)



• Overlearning - many controlled processes can become automatic with “overlearning”– motor skills– components of reading (Stroop)– letter search task– practice to avoid panic

• emergency response becomes automatic– concurrent tasks e.g. reading and taking dictation– retrieval of test items



• Investigations of– allocation– vigilance– switching– selection– flexibility

• focused vs. divided attention• e.g. jet fighter pilots and bus drivers



• Performance under two types of constraints– data limitations

• not enough data, no matter how much cognitive resources are applied

• e.g. poor quality copies, asked to land a jet– resource limitations

• can do better if pay more attention• e.g. listen to lecture and take notes

• Performance is limited by the demands that the task places on the cognitive system



• Measure capacity demands of a given task by amount of interference

• Secondary Task technique and cognitive effort– the harder the primary task the poorer the performance

on the secondary task– star tracing experiment


Secondary Task Technique

• Ellis– memory increases with increasing cognitive effort– measure effort with secondary task– primary task is hard or easy anagrams

• ootdcr vs. tordoc– secondary task is tone detection (probe)

– found - memory and RT to probe increases for harder anagrams

– measure difference in capacity demand



• Posner and Boies– letter matching and tone

detection

– look at RT to tone during different points in the task shows that cognitive load varies during the task

– notice RT during rehearsal and during decision

0

100

200

300

400

500

600

warning first second

RT



• Keele - investigate cognitive effort of different tasks

• Assumption - each task has two stages– receive sensory input and activate memory– mental operations based on memory activation

• mental operations such as:• recognition and search, compare and match,

rehearsal, response initiation, movement correction, counting (beyond subitization)

• Stage one takes little (or no) attention (effort) but stage two does


Other theories of attention

• Logogen model - levels of activation in memory– as concept reaches a threshold of activation you

become consciously aware of it (pay attention)

– preset criterion level of activation • ignore = set high• expectation = set low• redundancy and context = low• spatial location and physical characteristics can be

used to set high or low


Other theories of attention

• Posner and Keele– attention = mechanism that coordinates the different

codes– optional filtering of input based on physical

characteristics– cost and benefits of presetting attention– individual differences in flexibility

• focused and divided attention

• Treisman and Gelade– attention glues the codes back together

© 2001 Dr. Laura Snodgrass, Ph.D.1 Attention Determines which codes get processing Often associated...

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