Flashcards in Attention Deck (29)
the monkey business illusion
demonstrates a phenomenon known as inattentional blindness
It highlights the slightly worrying reality that we’re actually far less aware of things happening in the world around us than we think we are
It demonstrates how powerful selective attention is
- it enables us to focus on task relevant information while filtering irrelevant information out of awareness.
Also demonstrates the limited capacity of attention
William James (1890) attention definition
Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought.
Focalization, concentration, of consciousness are of its essence.
It implies withdrawal from some things in order to deal effectively with others…”
Harold Pashler (1998) attention definition
No-one knows what attention is, and there may not even be an “it” there to be known about
Competition for attention
Attention is a well-studied psychological process but is notoriously hard to define.
We are able to select a particular object amongst others and subject it to further processing or to act upon it.
This process of selection is generally what we mean by attention (although there are other forms of attention, e.g. sustained attention).
what is attention not?
the same as looking at something
- Change blindness
why should we care about attention?
attention plays a central role in consciousness
- What we attend to tends to be what we are conscious of.
Not claiming they are the same thing but they correlate extremely closely and attention seems to be pretty useful for consciousness.
demonstrates that we can be looking at something but not selectively attending to it
It also demonstrates the power of selective attention
If know where to look = pops out at you
Even when the change happens right in front of your eyes, you can miss it (change blindness)
Suggests attention may not operate over regions of space.
types of SA
multisensory – we can selectively attend to visual, auditory, tactile stimuli – and we can also switch attention between the senses.
Turning head or eyes to orient towards a stimulus
Paying attention to one thing while appearing to pay attention to another
the cocktail party effect
example of covert attention
are in a room with multiple audible conversations, and you are able to focus only on the person currently speaking to you.
However, you are also able to instantaneously switch attention to a neighbouring conversation whilst appearing to carry on listening to the other person if you hear something interesting.
Cherry (1953) exp to assess covert SA: the dichotic listening task
Subjects listened to two simultaneous sentences spoken into their two different ears and attended to one sentence and ignored the other.
They had to shadow the attended sentences, that is repeat them out loud.
results of Cherry's exp
Subjects could not detect most properties of the unattended channel:
- language used
- meaning of the message
Subjects did notice
- Gender of the voice
- Physical attributes, e.g. human vs musical instrument
Attention filters out most information
- Attention operates at an early stage in processing
- Info hits primary, sensory cortices first then moves to semantic areas
supports early selection model - only simple physical attributes of unattended information made it through the filter.
Attention operates at an early stage in the processing stream
- Filters out irrelevant information
stimuli are processed according to their physical attributes and are then selected by attention (note the point at which the many arrows become a single arrow in A) before reaching awareness and receiving more elaborate semantic analysis.
late selection models
suggest that all stimuli receive semantic analysis before attentional selection filters what enters into awareness.
e.g. hemispatial neglect – info not aware of may be influencing their behaviour
spotlight model fo attention (Posner, 1980)
argued that attention operates like a spotlight, enhancing sensory processing of objects in the spatial location to which it is directed.
Posner cueing paradigm - 'endogenous' cueing - voluntary attention
subjects must maintain fixation on the central cross and see an arrow pointing to the left or right and then a target appears on the left or right.
Subjects simply press left if the target appears on the left and right if the target appears on the right.
Posner found that RTs were faster to validly cued locations and slowest to invalidly cued locations
Posner suggested this was evidence of early selection because attention affected perceptual processing of the target stimulus (presumably via effects on lower level visual cortex).
interp of Posner cueing effects
attention increases efficiency of information processing by influencing sensory and perceptual processing
Posner hypothesised that the behavioural effects of cues were caused by neuronal enhancement/suppression in early visual cortical areas – Early selection
Attention enhances processing of objects occurring in particular spatial locations
problems with early selection theories: context effects
Often, subjects notice their own name, or other highly relevant information, on the unattended channel
How can they be aware of this if all information is being filtered out at a very early stage? The effect suggests that actually more information on the unattended channel is being processed than was suspected
Has to attend to some level unattended information in order to be able to hear your name/other relevant information
Ambiguous sentences in a dichotic listening task (MacKay, 1973)
- Attended stream: ambiguous sentence “They were throwing stones at the bank”
- Unattended stream: biasing word “river” or “money”
The biasing word had a clear effect
- If “money”, sentence interpreted as financial institution
- If “river” sentence interpreted as side of river
- Unconscious/”unaware” information can influence our behaviour
what is selected? objects/locations?
Objects are typically situated in a particular location so how can we distinguish between the effects of spatial attention and the effects of object-attention?
Egly et al. (1994) used a cuing paradigm to direct the attention of participants to different objects and locations.
Subjects saw two shapes and were cued to a location on one of the shapes
Then a target appeared either in the same object same location, same object different location, or different object.
Crucially, in the last 2 conditions, the spatial distance between the cue and target was the same but in one they both appeared in the same target, in the other they appeared in different targets.
RTs are faster if the cue and the target occur in the same object, even if they are in different locations.
The results demonstrate that attention operates in an object-based frame of reference.
Attentional selection operates on objects, not locations
Suggests attention does not operate like a simple spotlight
further evidence for object-based attention from inhibition of return
is means that a flash of light or something attention grabbing occurs in a peripheral location, and then a target appears either in the location of the flash (called a cued trial) or in the other location (uncued trial).
with short intervals between the cue and the target, RTs are faster to the cued location than to the uncued location.
However, as the interval between the cue and the target increases, this pattern reverses and RTs become slower to the cued location.
Tipper et al. (1991)
asked whether you could get a similar IOR effect when objects instead of locations were cued. In order to dissociate objects from locations they used moving stimuli.
Boxes rotated in a clockwise direction and one box was cued.
They then carried on rotating and a target appeared either in the previously cued box or the previously uncued box.
As you can see from the graph on the right, RTs were slower when the target was presented in a previously cued box, even though that box didn’t occupy the same location as the cue.
This shows that attentional suppression can also operate in an object-based frame of reference.
Substantial processing of unattended information occurs before attentional selection takes place
brain processes information about meaning of words, whether features in space combine to form objects etc. before selects what to attend to
a resolution to early v late selection debate Nillie Lavie: Load theory
task is to decide whether the target in the circular array is an X or an N while ignoring the distractor letter off to the side.
IVs in load theory
1) the perceptual load of the display, which was operationalised by having either a variety of distractors that shared features with the target (high load) or all the same distractors that shared no features with the target (low load)
2) The congruency of the distractor and target. The target and distractor could either be the same letter (congruent) or a different letter (incongruent).
indeed less distracted in the high perceptual load condition - the difference in RT between the incongruent and congruent conditions was lower (4ms) in the high perceptual load than in the low perceptual load condition (40 ms).
Distractor has more effect in the easier task
hypothesis in load theory
They hypothesised that perceptual load might influence the effect of distractors on visual search performance – in particular that distractors would intrude more under low perceptual load than high perceptual load.
perceptual load effects explained - high
Perceptual capacity is used up by the task of trying to find the target - none left for the distractor!
Support for early selection
(think back to the monkey business illusion)
perceptual load effects explained - low
The main task does not use up all your perceptual capacity so there is some left to process the distractors.
Support for late selection.