© 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)

© 2001 Dr. Laura Snodgrass, Ph.D.2 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

© 2001 Dr. Laura Snodgrass, Ph.D.3 Basic Information Processing Stimulus Sensory Register STM (working Memory) LTM Response

© 2001 Dr. Laura Snodgrass, Ph.D.4 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?

© 2001 Dr. Laura Snodgrass, Ph.D.5 Early Selection Model Sensory filter theory (Broadbent) Stimulus Sensory Register Sensory FILTER STM limited capacity LTM Response

© 2001 Dr. Laura Snodgrass, Ph.D.6 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

© 2001 Dr. Laura Snodgrass, Ph.D.7 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

© 2001 Dr. Laura Snodgrass, Ph.D.8 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

© 2001 Dr. Laura Snodgrass, Ph.D.9 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

© 2001 Dr. Laura Snodgrass, Ph.D.10 Late Selection Model Norman (68) Stimulus Sensory Register LTM Selection based on pertinence or saliency mechanism STM Response

© 2001 Dr. Laura Snodgrass, Ph.D.11 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

© 2001 Dr. Laura Snodgrass, Ph.D.12 Comparison Differences –location of filter (before or after LTM) –basis for selection Similarity –no permanent memory for unattended (not selected) information

© 2001 Dr. Laura Snodgrass, Ph.D.13 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

© 2001 Dr. Laura Snodgrass, Ph.D.14 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

© 2001 Dr. Laura Snodgrass, Ph.D.15 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

© 2001 Dr. Laura Snodgrass, Ph.D.16 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)

© 2001 Dr. Laura Snodgrass, Ph.D.17 Research on the capacity theory 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

© 2001 Dr. Laura Snodgrass, Ph.D.18 Research on the capacity theory Investigations of –allocation –vigilance –switching –selection –flexibility focused vs. divided attention e.g. jet fighter pilots and bus drivers

© 2001 Dr. Laura Snodgrass, Ph.D.19 Research on the capacity theory 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

© 2001 Dr. Laura Snodgrass, Ph.D.20 Research on the capacity theory 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

© 2001 Dr. Laura Snodgrass, Ph.D.21 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

© 2001 Dr. Laura Snodgrass, Ph.D.22 Secondary Task Technique 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

© 2001 Dr. Laura Snodgrass, Ph.D.23 Secondary Task Technique 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

© 2001 Dr. Laura Snodgrass, Ph.D.24 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

© 2001 Dr. Laura Snodgrass, Ph.D.25 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