Attention and Perception Unit 2: Selective Attention

Bottleneck Theory

Bottleneck Theory

describe selective attention as single/limited capacity channel

before, able to process many stimuli, after, only capable of processing one thing

keeps us from getting overstimulated

e.g. like autobahn, accident on one lane, now all cars must pass through singular lane

dichotic listening

one message in each side of headphones, different messages in different ear

→ studies showed selective&limited nature of attention, can only fully process one message at a time

→ shadowing task: two messages, told to only focus on one and repeat it

→ Split Span Task: subject presented with 3 pairs of digits, two at a time, must try to remember all pairs

Late filter model(Deutsch&Deutsch, 1963)

argues all info we detect receives sensory and semantic processing before it’s filtered

→ only most important stimuli pass through filter and reach STM

→ later, Norman added role of LTM: sensory inputs initially processed, during initial analysis, semantic properties of inputs are compared with LTM stores → if nonsense word heard, no match would be found

unattended and attended message receive equal processing before any info is filtered out

Automatic processing

• late filter model assumes all processing that occurs before the filter is automatic and doesn’t use up limited capacity of attention

• all processing that occurs after filter is more controlled and conscious, consumes attentional resources

Preattentive vs. attentive processing

• Neisser’s(1967) two-step perspective of attention → attention involves preattentive and attentive processing

  → preattentive processes: compromises initial, automatic processing of many sensory inputs to analyze the physical characteristics of inputs

  → attentive processes: more controlled, occur later in time and are slower, consume our attentional resources → can only pay attention to limited amount of things

Broadbent’s model

• predicts that sensory info is detected in both ears, even tho we're trying to ignore stimuli heard in one ear

• sensory info then reaches attentional filter, sensory info detected at one of the channels reaches STM and becomes conscious

• sensory info in the ear we're trying to ignore is filtered out before it reaches consciousness

  → suggests info is selected based on sensory/physical properties → bottom-up processing

Summary: little to no processing of unattended auditory message

treisman’s model

• Treisman argued the filter doesn't block out, but weakens stimuli, unattended info is also able to reach consciousness

• moray(1959) found when message contained meaningful word, participants would often remember contents of it

  → Treisman found this was only true 6% of the time, 94% don't remember unattended message

Summary: flexibility in processing of unattended info, its processed but less intensely