chapter four: attention Flashcards
what is attention
Attention: concentrating on information that is either internal or external
to oneself.
o Selective attention: attending to one thing and ignoring another
o Divided attention: paying attention to more than one thing at a
time
chapter four: attention
what is information processing
Information Processing: reflects ideas from a computer metaphor in
which incoming stimuli is processed in stages
information processing
dichotic listening task
Dichotic Listening Task: involves the presentation of 2 different messages
at the same time. Message #1 in the left ear and message #2 in the right
ear. Participants shadow (verbally repeat) the message in the attended ear
notes:
In a dichotic listening task a participant is presented with two different messages simultaneously specifically one message is presented in one year and another in the alternate year
participants might be required to report everything they heard from both ears or they might be required to attend to messages arriving from one eaer or what we call channel and to ignore the message that arrives from the other year this is called the to be ignored or the unintended channel
to make sure that participants are doing the task required they’re often asked to shadow the message that they are attending to that is they are to repeat what they hear
results of these dichotic listening tasks reveal that participants can do it they can do the task furthermore they often don’t know what was presented in the unattended here however sometimes information that is very salient such as your name is attended to when it’s presented in the “to be ignored channel”
findings of dichotic listening
o Cocktail party effect: ability to focus on one stimulus and filter out
other stimuli.
o Could report that there was a message
o Could not report the content of the message
o Could report the gender of the speaker
o Could report if the tone of voice changed
information processing
broadbent’s filter model
Broadbent’s Filter Model: A model of attention based on the findings of
dichotic listening tasks. This was the first flow diagram of the mind.
see figure 4.3
Information processing models are flow diagrams of the mind, the first flow diagram of the mind was broadbent’s filter model
human information processing approach to cognition reflects ideas from a computer metaphor in that there is information input and information storage.
information processing
sensory memory
Sensory memory: holds incoming unanalyzed sensory stimuli for a brief
duration.
o Iconic memory: holds visual stimuli for .24 - .50 seconds
o Echoic memory: holds auditory stimuli for 1-3 seconds
o Capacity is very large but not unlimited
notes:
sensory memory stores unanalyzed sensory stimuli for a fraction of a second sensory. memory can be divided into what’s called iconic and echoic stores
iconic store is for visual stimuli and echoic stores for auditory information.
visual stimuli is stored in the iconic sensory memory for about .242 to .5 seconds whereas auditory stimuli is stored for one to three seconds
information processing
filter
Filter: Attention serves as a filter in which only some of the incoming
information passes to the detector for higher-level recognition.
o Identifies stimuli based on physical characteristics (tone, intensity, pitch, location).
attention acts is a filter that allows only some of the incoming stimuli through for higher level recognition
the filter selects information based on physical characteristics of the message such as tone gender intensity pitch or even location
information processing
detector
Detector: processes all incoming information for higher-level
characteristics (e.g.,meaning)
information that passes through the filter stage will be processed for higher level characteristics such as its meaning by what’s called the detector. you can think of the detector stage as one in which the stimulus is recognized
information processing
short-term memory
Short-term memory: incoming information from the detectors is held here
for 10-15 seconds without rehearsing the information.
o Limited capacity (7+/- 2 chunks of information)
o Can transfer information to long-term memory which can hold
unlimited amounts of information for an unlimited duration.
notes:
after information is processed for a tier level characteristics by the detector this then enters the short term memory store and it’s healthier for about 10 to 15 seconds unless one rehearses this information in other words if the information is repeated, if you repeat the information to yourself it can remain in short-term memory beyond the 15 seconds while it is not completely clear what the capacity of short-term memory is a common estimate is that it can contain between 7 ± 2 chunks of information and a chunk of information just means that it’s a meaningful grouping of information
information in short term memory can then be transferred to long-term memory depending on how you encode encode we’re going to discuss later on in this class but it just means that it’s there’s some type of process you do with the information that transfers that information to long-term memory
early selection model
Early Selection Model: information selected before its meaning is
analyzed. Selection based on physical properties of the message (e.g.,
location, pitch).
o Broadbent’s Filter Model
o Treisman’s Attenuation Mode
broadbent’s filter model
Broadbent’s Filter Model: attention acts as a filter that BLOCKS to-beignored information.
*Problem with the Filter Model is that it does not explain why the meaning
of the ignored message can still be processed
notes:
Broadbent’s filter model is a type of early selection model that proposes to be ignored information is filtered at the beginning stage of information processing
attention will allow some information through and completely block other pieces of information that’s to be ignored
the problem with the filter model is that it does not explain why the meaning of the ignored message can sometimes still be processed
dear aunt jane study
Dear Aunt Jane Study (Gray & Wedderburn, 1960)
Instructed to shadow the left ear, however,
participants would report “Dear Aunt Jane” instead
of, “Dear 7 Jane” indicating that to-be-ignored
information was processed.
notes:
according to broadben;ts filter model the two be ignored information is completely blocked from further processing however in Gray and wedderburn’s dear aunt Jane study participants reported content from the 2 be ignored channel indicating that information was still being processed
to provide you written example during a dichotic listening task, participants would be instructed to shadow their left ear in the figure on the screen you would expect that the participants would shadow dear 7 Jane however what the researchers found was that participants reported hearing dear aunt jane indicating that the word aunt from the ignored channel had passed through the filter broadbands model can’t account for ignored information passing a filter that was meant to completely block it out
tresiman’s attuenation model
Treisman’s Attenuation Model: attention acts as an attenuator that
attenuates ignored information (like turning down the volume).
o Contains a dictionary unit that consists of words in memory
o Words with low activation thresholds (e.g. salient words) are likely to be
detected.
see figure
notes:
Another Early selection model is called treisman’s attenuation model
when attention is not directed at the unattended channel information in this channel is not blocked like in Broadbent’s model instead it is attenuated that’s like turning the volume down to weaken the message so that the probability of it being recognized is lower is lowered
instead of the filter that blocks information from the ignored channel it Broadbent proposes according to Treisman’s attenuation model information is analyzed by the attenuator for the messages physical characteristics, language and meaning
however the processing of meeting is rudimentary at this point the attended information then passes through the attenuator but the to be ignored information is attenuated making its signal weaker than the than the attended message
next the information is analyzed by what is called the dictionary unit. the dictionary unit consists of words in memory with varying thresholds for detection
salient words such as our name will have a low activation threshold meaning that even when it’s a weak signal it can still be detected
treisman’s attenuation model
see diagram
in this diagram you can see that the message enters the attenuator where the message from the ignored and attended ear are processed the arrows exiting the attenuator differ in their size
the larger arrow represents a strong signal from the attended channel and the thinner arrow represents a weaker attenuated message both the attended and unattended messages passed through to the dictionary unit
if the signal strength of the words from the attended or unattended channel reaches its activation threshold the word will be detected
MacKay’s late selection model
MacKay’s Late Selection Model: Information selected for further
processing occurs after the meaning of the message is analyzed.
In Mackay’s late information model, information is filtered after the meaning of the message is recognized, in other words in a late selection model the filtering of information happens after all incoming information is processed for meaning
mackay (1973)
see slide 17
evidence for a late selection model comes from mackays’ 1973 study participants completed a dichotic listening task
in the attended ear they were presented with an ambiguous message such as they were throwing stones at the bank
ank can refer to a financial institution or it could be the Bank of a river participants’ interpretation was influenced by words presented in the unattended ear if the word money was presented in the unattended year they were likely to select they threw stones at the savings and loan association yesterday as the sentence that closely matches the meaning of what they heard from this McKee proposed that filtering information occurs only after the meaning of both messages from the attended and unattended ear are processed
early + late selection
- Task and type of stimuli determine whether selection of information for
processing occurs early or at a later stage.
processing capacity + perceptual load
Lavie’s Load Theory of Attention: Focuses on the amount of information
that can be processed at one time.
o Processing capacity: amount of information one can process at a time
o Processing load: difficulty of the task
o High-load tasks
o Low-load tasks
notes:
Load theory of attention Is a capacity model of attention, unlike the early and late selection models of attention, capacity models focuses on the amount of information that can be processed at a time based on task difficulty.
difficult tasks are considered high load tasks whereas relatively easier tasks are considered to be low load tasks
processing capacity + perceptual load
see figure
participants are presented with the display of letters arranged in a circle and they are instructed to detect the letter X or N and respond by pressing the corresponding keys, you will notice that participants are quick to detect the letter N when it is surrounded by Os
the easy task is a low load task however in the second display detecting X takes much longer because it’s surrounded by various letters such as Z K M&H&W the hard task is considered a high load task that involves more processing capacity to complete
now the more interesting finding is shown in figure B a distractor is introduced in the form of a dog cartoon character this cartoon is a task irrelevant stimulus which means that it’s not needed for task completion
what was found was there was greater impaired response times for the easy condition relative to the hard condition. that suggests that the low load easy task is associated with larger amounts of leftover processing capacity that you used for processing task irrelevant stimuli
scanning a scene
Tracking how one visually scans a scene is one way to measure overt
attention .
o Visual scanning: eye movement from one stimulus to anther
o Overt attention: shift of attention by moving where the eyes are looking
scanning a scene
Fixation: short pauses on points of interest
Saccadic eye movement: rapid movements of the eyes between fixations
scanning a scene
stimulus salience
Stimulus Salience: bottom-up processes in which
physical properties of stimuli captures attention.
o Attentional Capture: rapid shift of attention to a stimulus
Saliency map: map of a scene that indicates points of
stimulus salience. Lighter areas are highly salient.
scanning a scene
scene schema
Scene schema: knowledge of what is in a
particular scene. Guides fixations from one
area of a scene to another
ex: Participants look longer at the printer because
it does not fit the scene schema (Võ & Henderson, 2009)
scanning a scene
visual search
- Visual search: scanning a scene to find an object
- Eye movements determined by task demands
- Eye movements typically precede a motor action
outcomes of attention
Covert Attention: shift of attention without eye movement.
Precueing: providing a cue to help participants complete a subsequent
task.
outcomes of attention
Posner et al.’s (1978) study
procedure:
- valid trials (precue location congruent with target location)
- invalid trials (precue location incongruent with target location)
Posner and others conducted a visual priming study in which they examined how attention to a stimulus location facilitates responding to that same location on a later trial
on valid trials the precue location was the same as the target location we call this congruent an invalid trials the precure location was different from the
results:
o Faster responding to target on valid trials
compared to invalid trials
o Covert attention in Posner et al.’s (1978)
study facilitated information processing.
location we call that incongruent
the procedure of their study involved the presentation of a cue while having participants fixate on the centre cross a pointing arrow cues a location then a target square appears that is either congruent or incongruent with the cue location results indicated that reaction time to the target was significantly faster on valid trials as shown by the red bar in other words the study revealed that attention to a location can speed responding to that same location
outcomes of attention
same-object advantage:
same-object advantage: cueing attention to part of an object facilitates responding to all parts of that object
ex: study conducted by Egly et al. (1994)
Same object advantafe is the facilitated Responding to all parts of an object when attention was previously directed to a part of that object
in egly and others 1994 study, one of four locations on an object was queued
outcomes of attention
Egly and coworkers (1994)
procedure:
- cue one of 4 locations
- button press response
results:
- faster responding to cued location
- faster responding to location on the cued object compared to uncuded object
notes:
during the pre cue trial a location is cued. in this example the upper part of the right rectangle is queued to simplify our understanding of the procedure your textbook labeled the locations with letters CDA&B so location A queued then the queue disappears
next participants are required to press a button it the target appeared anywhere on the bars and participants were fast to respond to a location that was previously queued for instance if location A was queued and the target appeared at location a they were quick to detect the target however what’s interesting is that they were fast to detect a target if it was anywhere on that rectangle
so you will notice that if the target appeared at location B response times were 358 milliseconds which is still faster than if the target appeared at location C which is a different rectangular bar. so there was the same object advantage
outcomes of attention
datta and deyoe (2009)
procedure:
- fixate eyes on center of a stimulus disc
- attend to areas of this disc
*record fMRI of brain activity
results:
- collection of brain activation areas -> created attention map for participant
- a participant’s “secret place” was identified based on their attention map
divided attention
schneider and shiffrin (1977)
schneider and shiffrin (1977) : practice improves divided attention
procedure:
see figure
results:
after many trials, the detection of the target became an AUTOMATIC PROCESS (without intention or cost to cognitive resource)
divided attention
divided attention possible for well-practiced easy tasks but not for difficult tasks (ex: driving through heavy traffic)
participants on cell phone missed twice as many red lights and took longer to apply the brakes (strayer & Johnston, 2011)
distractions
mind wandering: thoughts from within/ daydreaming happens frequently
- can distract you from a tasl (ex: mindless/zoned out reading) and impair performance
distractionL stimulus that interferes with the processing of another stimulus
what happens when we don’t attend
inattentional blindness: stimulus that is not perceived even if a person might be looking at it
what happens when we don’t attend
cartwright-finch & lavie (2007)
o 6 Trials
o Indicate which line is longer
(horizontal or vertical)
o Trial 6, a small square appears
o Participants do not notice the square
What Happens When We Don’t Attend
inattentional deafness:
Inattentional Deafness: impaired hearing when focused on a difficult
visual task.
Task = detect “X”
Tone presented during the task
Low detectability of the tone on
hard trials
What Happens When We Don’t Attend
change detection:
Change Detection: if shown two versions of a picture, differences
between them are not immediately apparent (called continuity errors in
films).
Experiencing a Coherent World
binding
binding: the process by which features are combined to create our perception of an object
ex: any stimulus, even one as simple as rolling ball, activates a number of different areas of the cortex
- rolling ball
- location, depth, motion, color, shape
binding is the process by which these seperated signals are combined to create a unified percept
Experiencing a Coherent World
binding problem:
binding problem: how do features (colour, form, motion, location) combine for object perception
Experiencing a Coherent World
feature integration theory
treisman
1) preattentive stage: each feature processed in seperate areas of brain
2) focused attention stageL features combined
see figure
“free floating” features
see figure
illusory conjunctions
Illusory Conjunctions: inappropriately combining features of different objects.
Triesman and Schmidt (1982)
Step 1: Report the digits (to reduce attention
to the shapes).
Step 2: Report the shapes
Results: illusory conjunction on 1/5th of trials
o Illusory conjunctions more likely to occur if there is parietal lobe
damage (e.g., Balint’s Syndrome)
o Illusory Conjunctions are less likely to occur with top-down
knowledge of how features should be combined.
Experiencing a Coherent World
feature search: search for a single object based on a single feature (ex: horizontal line)
conjunction search: search for an object based on two or more of its features (ex: horizontal line that is green)
see image
reflection questions
1.Describe what a dichotic listening task is and its purpose.
2.What is the association between a scene schema and attention?
3.Explain the feature integration theory.
When a precue location is congruent with the target location, Posner called this a __________ trial.
valid
Cartwright-Finch and Lavie (2007) presented 6 trials with a horizontal line that intersected a vertical line (making the figure of a cross). The authors found:
inattentional blindness on trial 6
The “Dear Aunt Jane” study conducted by Gray and Wedderburn(1960) revealed:
some of the to-be-ignored information is processed
