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PSY2303 Cognition and Emotion > Attention > Flashcards

Flashcards in Attention Deck (29)
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1

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

2

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…”

3

Harold Pashler (1998) attention definition

No-one knows what attention is, and there may not even be an “it” there to be known about

4

defining attention

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).

5

what is attention not?

the same as looking at something
- Change blindness

6

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.

7

change blindness

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.

8

types of SA

overt

covert

multisensory – we can selectively attend to visual, auditory, tactile stimuli – and we can also switch attention between the senses.

9

overt SA

Turning head or eyes to orient towards a stimulus

10

covert SA

Paying attention to one thing while appearing to pay attention to another

11

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.

12

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.

13

results of Cherry's exp

Subjects could not detect most properties of the unattended channel:
- language used
- meaning of the message
- content

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.

14

early selection

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.

see notes

15

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

16

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.

17

Posner cueing paradigm - 'endogenous' cueing - voluntary attention

see notes

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.

see notes

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).

18

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

19

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
Change blindness

20

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.

see notes

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.

see notes

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

21

further evidence for object-based attention from inhibition of return

see notes

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).

see notes

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.

22

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.

23

late selection

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

24

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.

see notes

25

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)

see notes

2) The congruency of the distractor and target. The target and distractor could either be the same letter (congruent) or a different letter (incongruent).

see notes

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

26

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.

27

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)

28

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.

29

effect of perceptual load on visual cortex activation - Schwartz et al. (2005)

see notes

In one (low load) they just had to detect any red shape.

In the other (high load) they had to detect specific conjunctions of shape or colour – e.g. a yellow upright T or a green inverted T.

Note here that exactly the same amount of visual stimulation was used in the 2 conditions, what we mean by perceptual load is the perceptual difficulty of the task.

The main task was flanked by these checkerboard stimuli which produce high levels of activation in visual cortex

The graph shows the difference in activation between low and high load conditions.

They found that visual cortex activation due to the checkerboard stimuli was much higher in the low load condition – the neurophysiological correlate of Nilli Lavie’s behavioural data.

Essentially, in the high load condition subjects are so focused on the main task that they are able to filter out the irrelevant checkerboard but this filter doesn’t operate so well in the low load condition.

Fascinatingly these effects were observed at the earliest level of visual processing.