selective attention Flashcards
what is the cocktail party problem?
what sort of listening is this similar to in a lab?
trying to divide attention between voices
dichotic listening - play 2 different streams of spoken words in earphones in each ear
what did Cherry find?
we can’t understand/remember the contents of 2 concurrent spoken messages
best we can do is alternate between attending selectively to the speakers
when is shadowing messages successful and not successful?
and what is it?
- repeating aloud one of the messages whilst ignoring the other
successful: if messages differ in physical properties e.g voice
not successful: if differ only in semantic or lexical content
what 2 changes do people notice/not notice in unattended messages?
- physical changes - e.g location and voice
2. NOT semantic changes e.g if changed from meaningful to meaningless
who focused on shadowing and unattended messages?
Treisman and Moray
why don’t we process meaning if unattended words?
unattended words are filtered out early on basis of physical attributes before we access meaning
so aware of physical changes but don’t think to process meaning
how to extract meaning from unattended messages?
describe this process?
have to switch attention filter between the unattended and attended messages
slow and effortful process
what is Broadbent’ filter model of human information processing?
selective filter (all-or-none and can’t be bypassed) directed to only one source at a time and is done early
- after sensory analysis but before semantic analysis and conscious memory
only info that passes through filter is recognised etc.
why may filtering not be all-or-none and what does this mean?
all or none - info either gets through the filter or not at all
evidence that unattended speech could activate meanings - partial breakthrough:
1) own name in unattended speech
2) interpretation of lexically ambiguous word in attended influenced by meaning of words in unattended
3) conditioned word with electric shock
skin response evoked by the word in unattended message even though not ‘noticed’ that word was there
also happened for similiar words so meaning activated
describe late selection theories?
both attended and unattended words processed up to and including identification and meaning activation
relevant meanings picked out if salient or currently relevant
what don’t late selection theories explain?
skin response to unattended probe word weaker than to attended (should be the same)
selection on the basis of sensory attributes more efficient than selection on basis of meaning
what is Treisman’s filter-attenuation theory?
early filter but later selection
not all-or-none (block) but attenuates info from unattended sources (weakens force - so unattended words can still activate meanings if salient)
early filtering is an optional strategy (not bottleneck - meaning necessary)
how did a task show that early selection is optional not a structural bottleneck?
played sequence of digits to right ear
had to be shadowed (spoken aloud) and left ear unshadowed
found more letter detected in shadowed (right ear) than left ear
what did Daniel Simon find?
what does this suggest?
that many missed highly salient events in unattended stream when focusing on another stream
events of unattended stream even though in visual field not processed to level of meaning
suggests that there’s an early filter for visual info
what is the attentional spotlight of covert attention?
what is meant by covert attention?
covert attention - attending to parts of visual field away from fixation
attentional spotlight-
endogenous cueing (arrow suggesting which side image would appear)
made people respond faster in all tasks
so faster in expected and slower in unexpected side
describe exogenous cues?
compared to endogenous cues?
reaction time faster after change in stimulus when box flashed (exogenous)
exogenous attraction of spotlight is faster than endogenous movement
what did Mangun find?
P1 component larger in activity when stimulus appeared in attended location than unattened
filtering happening very early
findings suggesting endogenous selection occurs very early in processing?
fMRI BOLD response reacted to a greater degree when attention directed to that side (endogenous selection)
how does the efficiency of early selection depend on processing load?
evidence to support this?
what is this theory called?
perceptual load theory
selection good when input takes up all processing capacity as no space for extraneous distractors
when proessing load low, spare capacity to process extraneous distractors and influence later dealt with by selection process
what are the 3 functions of selective attention?
- defensive filtering - protecting high level limited capacity systems from overload
- positive selection-for-action - prioritising one object (most beneficial) to aid intended actions or further processing
- Treisman’s feature-integration theory - integrates features in visual field to form object representations (bottleneck between sensory processes and representation)
what is the difference between what early and later researchers used to measure how early selective attention takes place?
early - listening tasks
later - visual reaction time tasks
describe how we attend to something using vision?
look at object which we are attending to bring retinal image onto the fovea
evidence in support of perceptual load theory?
if processing load low, then incongruent distractor slows response relative to congruent (if one letter different to the other as opposed to the same)
if processing load increased then distractor didn’t slow down response if incongruent as distractor not even processed
what does Treisman’s feature-integration theory predict?
- unattended features won’t combine properly
2. unattended objects won’t result in stable object representations
