Structural And Capacity Theories And Control Of Visual Attention Lecture 3

Front 1

Recap: What is Filter theory, and what is the Early vs. Late Selection debate?

Back 1

Developments from Filter Theory (Broadbent, 1958)

1. Attention viewed as a selective filter to protect a limited-capacity system from overload

2. Argument about what gets through the filter and where the filter is located

Front 2

What is the evidence for Early Selection Theory?

Back 2

*Filter before LTM

Unattended target detection (through "tap"): good in different voice (Treisman & Riley, 1969) ; poor in same voice (Treisman & Geffen, 1967)

Front 3

What is the evidence for Late Selection Theory?

Back 3

*Filter after entry to LTM

Semantic activation on unattended channel (McKay, 1973; Von Wright, Anderson & Stenman, 1975)

Front 4

Did the Early Selectionists see the Late selection findings as critically damaging to their point of view?

Back 4

No. Do not deny weak activation of semantic material on unattended channel. Indirect measures don't show it occurs to the same degree

Front 5

As both theories had more core similarities than differences, where did the focus turn in studying Attention?

Back 5

Studying Attention distribution across multiple channels

Front 6

Who first studied Divided Attention?

Back 6

(Moray, 1970)

He compared two conditions

1. Selective: Monitor for targets on one channel only

2. Exclusive OR (XOR): Monitor both channels, no simultaneous targets

Front 7

What were the results?

Back 7

Selective condition: It was found to be a challenging task, only 67% of targets were detected correctly (Selective Attention baseline)

XOR condition: only 54% of tones identified

Front 8

What was the conclusion?

Back 8

So the question is “ is your performance poorer when you divide attention?”. Answer is yes, due to the cost of divided attention.

Front 9

What was Moray's (1970) third study condition?

Back 9

Inclusive OR (IOR): Monitor both channels, simultaneous targets possible

Compare simultaneous targets (AND trials) and nonsimultaneous (OR trials)

Front 10

What were the results for the IOR - OR trials?

Back 10

where target is left or right but not simultaneous performance was 52% correct (not much different to exclusive XOR condition of 54%)

Front 11

What were the results for the IOR - AND trials?

Back 11

upon presentation of double target the performance drops to 31% correct; people are particularly bad at detecting two targets at the same time

Front 12

What were Moray's (1970) overall conclusions?

Back 12

SEL > OR (both XOR & IOR) > AND

Front 13

Which Selection Theory fits with the SEL > OR relationship?

Back 13

Early Selection (ES) but NOT Late Selection

Front 14

Why does ES fit with the SEL > OR relationship??

Back 14

This is because you attenuate signals when you are not attending to them as much, so reasonably this applies when your are dividing attention too (ES). BUT when pertinence (LS) is at work, we should not see any deficit between two stimuli because there is no competition.

Front 15

Which Selection Theory fits with the OR > AND relationship?

Back 15

Late Selection (LS) but NOT Early Selection

Front 16

Why does LS fit with the OR > AND relationship??

Back 16

This is because ES doesn’t predict any particular cost of double targets. BUT pertinence (LS) tries to select two things through the filter at the same time, there will cost (analogous to two big people trying to get through a doorway at the same time). Only one stimulus can get through the filter there comes a cost

Front 17

As neither ES nor LS theories [Structural (Bottleneck) Theories] could explain Divided Attention very well, what is another set of theories created to explain Divided Attention?

Back 17

Capacity (Resource) Theories

Front 18

What are the set Structural Theories?

Back 18

1. Some neural structures can only deal with one stimulus at a time(neural restrictions = deficits)

2. Competition produces processing “bottleneck” (filter theory)

3. (ES: bottleneck getting into LTM; LS bottleneck getting out)

Front 19

What are Capacity Theories?

Back 19

1. Information processing is mental work (e.g. pupil dilation)

2. Processing requires activation of neural structure

3. Limited capacity to activate structure

Front 20

What is Kahneman's (1973) Capacity Theory?

Back 20

1. Reduction of capacity produces deficit in divided attention tasks

2. Differs from structural theories because capacity can be allocated flexibly to simultaneous tasks

Front 21

What did Strayer and Johnston (2001) study with Divided Attention?

Back 21

Talking on a mobile phone interferes with driving

Front 22

What is Attention Operating Characteristic (AOC)?

Back 22

Consistent with idea that capacity is a flexible and continuously allocatable resource.

Says how performance on two simultaneous tasks trades off as you vary the fraction of attention.

Front 23

What did Bonnel & Hafter (1998) study?

Back 23

Detection vs. Discrimination

Front 24

Was AOC applicable for both Detection and Discrimination, or just one?

Back 24

Just Discrimination.

Chery’s original dichotic listening studies suggested that just detection of sensory features was pre-attentive not required capacity. While understanding of meaning requires focal attention, we are prepared to argue that discrimination, distinguishing one signal from another, is a cognitively elaborated and demanding task, like understanding meaning then this kind of trade-off makes sense

Front 25

What is one pro and one con of Capacity Theory?

Back 25

PRO: Emphasises divided attention, flexibility of attentional control

CON: Shortcoming is its vagueness (can always come up with a capacity explanation)

Front 26

What is an alternative approach to Capacity Theory?

Back 26

Signal Detection Theory (SDT)

Front 27

What are Phillip's five points on SDT?

Back 27

1. Theory of how we make decisions about weak or difficult stimuli
2. Mental representations of stimuli are statistically variable or “noisy”
3. Attending to multiple stimuli increases amount of noise and reduces accuracy
4. Makes mathematically precise predictions about divided attention costs
5. Many results attributed to capacity limitations can be explained by changes in the amount of noise....

Front 28

Why are psychologists only interested in 'covert' attention?

Back 28

Because it is the movement of attention independent of eye movements, called Attentional Orienting

Front 29

What is Attentional Orientating?

Back 29

Shifts of attention aside from physiological manifestations

Front 30

What is Posner's metaphor for Visual Attention?

Back 30

Spotlighted Attention: enhances ability to process stimuli in particular location, at the expense of other locations (it is either degraded or receives no processing at all)

Front 31

What paradigm did Posner come up with to support his metaphor/theory?

Back 31

Spatial Cuing Paradigm

Front 32

What is Stimulus Onset Asynchrony (SOA)?

Back 32

the interval (100-300ms) between the cue and the stimulus

Front 33

What is the average Reaction Time?

Back 33

100-500ms, depending on whether the stimulus was cued or miscued or not-cued (neutral cue).

Front 34

What were Posner's results?

Back 34

The effects of attentional cueing is to produce symmetrical costs and benefits on RT relative to the neutral baseline

Attentional benefit = valid cues

Attentional cost = invalid cues

Attentional baseline = neutral cues

Front 35

What are the two interpretations of Posner's experiment?

Back 35

1. Shifts of spotlight:Costs in terms of time (like filter theory)

2. Capacity theory: Neutral capacity spread across locations; Focused capacity concentrated on one location

*Hard to test between these alternatives

Front 36

Does Attentional Orientating have two separate orientating systems?

Back 36

Yes.

Top down cognitively controlled shift of attention (i.e. choose things that are interesting and behaviourally relevant)

Bottom up shift in attention elsewhere if something unpredictable happens (e.g. predator, threat)

Front 37

Can clinical patients patients show deficits in either system?

Back 37

Yes.

1. failure to focus attention

2. failure to disengage attention

Front 38

What are the labels for the two separate orientating systems

Back 38

1. Endogenous(voluntary; cognitive, need to interpret)

2. Exogenous(reflexive; spacial, no need to interpret)

Front 39

What is the first bit evidence for Endogenous and Exogenous systems?

Back 39

Endogenous processing occurs when Central (symbolic) cues are presented. Central effect peaks slowly and is sustained.

Exogenous processing occurs when Peripheral (spatial) cues are presented. Peripheral effect peaks rapidly and is transient.

Front 40

What is the second bit evidence for Endogenous and Exogenous systems?

Back 40

Different effects of load (Jonides, 1981)

Voluntary orienting affected by load; reflexive orienting is not

Front 41

What is the third bit evidence for Endogenous and Exogenous systems?

Back 41

Inhibition of Return:Found only with peripheral cues, not with central cues

Front 42

What is the explanation for Inhibition of Return?

Back 42

if you use flash peripheral cues it produces fast attentional effect, peaking at ~150ms but its transient. If you increase the SOA still further the attention effect starts to dissipate. What happens if you make the SOA really long e.g. 300ms. Well, strikingly the cueing effect actually reverses. So this curve, which is describing the mean RT between valid and invalid cues actually passes below the x-axis. This means you are actually slower at the cued location than the uncued location. At these long SOAs this negative cueing effect actually says you are not faster at the cued location- you are slower. In other words, if you present a flash peripheral cue, wait for 300ms then present a stimulus, you’re slower at the cued location than the uncued location.

Front 43

Which shape of graph is shown for Discrimination?

Back 43

Curved AOC

Front 44

Which shape of graph is used to show Detection?

Back 44

The squared graph, and detection doesn't require much attention.