Problem A: Failures of Awareness - The Case of Inattentional Blindness
- Inattentional blindness: failure to notice unexpected objects or events when
attention is focused elsewhere
- many ways that our perception of the world is limited
- we perceive only that which receives the focus of our cognitive efforts → our
attention
- dichotic listening: set of headphones that play two completely different speech
streams (one to left and one to right ear) → attention demanding task
- won’t notice if the speaker in your right ear switches to a different language
or is replaced by a different speaker with similar voice
- won’t notice if content becomes nonsensical
- even when speaker in right ear say your name, you will notice ⅓ of the time
- you will only tend to notice only large physical changes (e.g. a switch from a
male to a female speaker), but not substantive ones (except in rare cases)
⇒ this is not because of the limits of your auditory senses → form of cognitive deafness, due
to the nature of focused, selective attention
- Inattentional deafness: the auditory analog of inattentional blindness. People fail to
notice an unexpected sound or voice when attention is devoted to other aspects of a
scene
- Selective listening: a method for studying selective attention in which people focus
attention on one auditory stream of information while deliberately ignoring other
auditory information
- selective listening task → highlights the power of attention to filter extraneous info.
from awareness while letting in only those elements of our world that we want to
hear
- focused attention powerful to observation → we zero in on what we want to see or
hear while filtering out irrelevant distractions
- consequence → we can miss what would otherwise be obvious and important
signals
- the same holds for vision → visual analogue for dichotic listening experiment
(Neisser & Becklen, 1975)
- subjects view a video of two distinct and overlapping events e.g. one event
people playing a hand-clapping game; second event people pass a ball
- because the two events were partially transparent and overlapping, both
produced sensory signals on the retina regardless of which event received
the participant’s attention
- when subjects asked to monitor one of the events they often fail to notice
unexpected events in the ignored video stream
, - participants were unaware of events happening outside the focus of their
attention, even when looking right at them
- could tell that other things was happening on the screen, but unaware of the
meaning or substance of those things
Experiment by Neisser (1979)
- test the power of selective attention to induce failures of awareness
- subjects watched a video of two teams of players → one wearing white shirts and
one wearing black shirts
- subjects were asked to press a key whenever the players in white successfully passed
a ball, but to ignore the players in black
- a person wearing a raincoat and carrying an umbrella strolled through the scene →
so intently focused on spotting passes that they often missed the “umbrella woman”
After these experiments
- findings were well known but for decades researchers dismissed their implications →
displays had odd and ghostly appearance
- no studies built on Neisser’s method for nearly 20 years
- first replication by Simons & Chabris (1999) → found that many people missed the
umbrella woman
- what changed → version of the video in which all of the actions of both teams of
players were choreographed and filmed with a single camera. The players moved in
and around each other and were fully visible
- they added the gorilla → half of the observers missed the gorilla when counting
passes by the team in white (inattentional blindness)
- people much more likely to notice unexpected objects that share features with the
attended items in a display (e.g. gorilla and players in black)
- however, even unique items can go unnoticed → e.g. 30% failed to detect a bright
red color (visible for 5 seconds, in a task of counting only black items (no other colors
in the display)
Factors that have crucial influence on noticing:
- the effort you put into the attention demanding task → if you have to keep separate
counts of bounce passes and aerial passes you are less likely to notice the gorilla
- if you are tracking faster moving objects, your are less likely to notice
- the more effort a cognitive task requires the more likely it becomes that you'll miss
noticing something significant
- you can even miss unexpected visual objects when you devote your limited cognitive
resources to a memory task → limits are not purely visual (limits of capacity of
attention)
- without attention to the unexpected event → unlikely to become aware of it
Inattentional blindness - outside of the laboratory:
, - occurs also in the real world and under more natural conditions
- famous police misconduct case: police officer was convicted of lying because he
claimed not to have seen a brutal beating, while he was chasing a murder suspect
and ran right past the scene of the brutal assault
- Chabris et al., 2011 → recent study that simulated the police case → subjects jogged
behind an experimenter who ran right past a simulated fight scene
- at night → 65% missed the fight scene; at daylight→44% missed it
- few people can multitask → talking on phone while driving or walking decreases
situation awareness
- illustration of cell phone-induced inattentional blindness (Hyman et al., 2010) →
people talking on a cell phone as they walked across a campus were less likely than
others to notice a unicycling clown who rode across their path
- under conditions of focused attention→we see and hear far less of the unattended
information than we might expect
- the greater the demands on attention, the less likely people are to notice objects
falling outside their attention
- the more like the ignored elements of a scene, the less likely people are to notice
- the more distracted we are, the less likely we are to be aware of our surroundings
Individual differences in inattentional blindness:
- growing understanding of the limits of attention and factors that lead to more or less
noticing → less understanding of individual differences in noticing
- controversial topic
- few studies suggest that those who have a greater working memory capacity are
more likely to notice unexpected objects → people with more resources
- other studies find no such relationship: Those with greater working memory
capacity are not any more likely to spot an unexpected object or event
- people with greater working memory capacity also tend to be better able to
maintain their focus on their prescribed task →they should be less likely to notice
- study: measured how well people could track moving objects around a display,
gradually increasing the speed until people reached a level of 75% accuracy (Simons
& Jensen, 2009)
- tracking ability varied greatly
- ability to track objects more easily was unrelated to the odds of noticing an
unexpected event
- as long as people try to perform the tracking task, they are relatively unlikely
to notice unexpected events
- study suggests → ability to perform a task does not predict the likelihood of
noticing
Findings vs. intuition:
, - most people are confident they would notice the chest-thumping gorilla-90%
- people are convinced that they would spot errors in movies or changes to a
conversation partner
- explanation for this mistaken intuition: our experiences themselves mislead us
- rarely experience a study situation such as the gorilla experiment
- most of the time → happily unaware of what we have missed, but we are fully aware
of those elements of a scene that we have noticed
- if we assume our experiences are representative of the state of the world, we will
conclude that we notice unexpected event
Evolution:
- limits of attention coupled with mistaken impression that important events will
capture our attention → why did our species survive?
- our ability to focus attention intently might have been more evolutionarily useful
than the ability to notice unexpected events → for an event to be unexpected, it
must occur relatively infrequently
- most events don’t require our immediate attention; if inattentional blindness delays
our ability to notice the events→ consequences minimal
- social context → others might notice that event and call attention to it
Consequences of inattentional blindness in modern society:
- we face greater distractions and move at greater speeds than in the past → even
minor delay in noticing something unexpected can mean a lot
- talking on the phone → increases your odds of missing the child who runs into the
street or the car that runs a red light
- why do people continue to talk on the phone when driving? reason might be the
same mistaken intuition that makes inattentional blindness surprising → drivers do
not notice how distracted they are
What to do about inattentional blindness?
- not much - cannot overcome the limits of attention
- you can take steps to limit its impact by recognizing how your intuitions will lead you
astray
1. maximize the attention you do have available by avoiding distractions
(especially under conditions for which an unexpected event might be
catastrophic) →
a. e.g. put your phone on mute when driving
b. If you know that you will be tempted and you know that using your
phone will increase inattentional blindness, you must be proactive
2. pay attention to what others might not notice