Selective attention

Question 1

What is the definition of attention?

Answer 1

A psychological commodity applied to enhance sensation or awareness of particular events

Question 2

Why is selective attention important?

Answer 2

In order to guide behaviour, we need to select perceptual input (the mass we are receiving from our senses, perceptually different but temporally similar) that is salient but also relevant (we can’t just go responding to everything that catches our attention) i.e. we need to PRIORITISE to suit our needs

Question 3

What did Titchener suggest regarding attention?

Answer 3

Operates by increasing clarity of perceptual events

Question 4

What conclusions were made from Broadbent’s Dichotic Listening task?

Answer 4

The unattended message is processed at an early perceptual level (can identify features like pitch) but no phonological or semantic higher levels
i.e. we can perceive stimuli without conscious awareness but we cannot assign any useful meaning to it

Question 5

What was Broadbent’s Selective Filter Model of attention?

Answer 5

Human information processing is capacity limited so we need constraints at post-perceptual levels
EARLY FILTERS - protects limited resources by filtering on the basis of low level perceptual properties
LATE SELECTION - after evidence that some unattended input could be processed at semantic level, it was suggested that the filter occurred to protect limited control/output capacity (limits of working memory)

Question 6

What is Treisman’s attenuation model?

Answer 6

He found that responses to unattended target words were reduced rather than completely gone, suggesting that the locus of selection could be flexible and determined by multiple factors

Question 7

What did Treisman suggest affected the locus of selection?

Answer 7

Perceptual properties
Relevance to the individual’s needs (cocktail party effect)
Cognitive load imposed by task

Question 8

What do we mean when we say that exogenous attention is “biphasic”?

Answer 8

Cues speed then slow responses at attended location (bottom-up facilitation followed by inhibition)
Exogenous attention rapidly orients to salient stimuli but fades quickly again unless the stimuli is actually important

Question 9

What is meant when we say that endogenous attention does not lead to inhibition of return?

Answer 9

Inhibition of return refers to an orientation mechanism that briefly enhances the speed and accuracy with which an object is detected after the object is attended, but then impairs detection speed and accuracy i.e. how exogenous attention works

Question 10

What is endogenous attention like?

Answer 10

Facilitation and inhibition are slower acting and require conscious effort but are maintained (top-down facilitation)

Question 11

What is a modern technique for studying attention?

Answer 11

Using EEGs and event-related potentials - compare potentials for attended and unattended stimuli and observe differences in waveform amplitudes that correlate with the behavioural results of reaction time differences
e.g. Amplitude of the waveform is larger in valid endogenous trials

Question 12

What can we conclude about exogenous and endogenous attentional processes?

Answer 12

The differences observed in both behavioural and neural measures suggests that they are controlled by separate cortical and subcortical mechanisms - evolutionarily advantageous to have one system detecting salience while another keeps ya focused on goals

Question 13

What is an example of how these systems interact?

Answer 13

In the stroop task
Inhibition important here to prevent verbalisation of the automatized response - inhibit pre-potent (learned) associations between the word and colour in order to simply identify the colour
Attentional inhibition slows response time

Question 14

How can we use brain imaging techniques to study attention?

Answer 14

Measure changes in regional blood flow - active neurons require greater blood flow
Can observe how multiple areas light up in congruent trials, but for incongruent ones when the goal becomes more effortful we have to recruit circuity from other regions to help dampen down the irrelevant info and enhance the relevant

Question 15

What do we have to do during VISUAL SEARCH?

Answer 15

e.g. in Where’s Wally
Match the scene with our internal perception of Wally (top-down)
We have our working memory to help us understand what we are looking for, and the perceptual properties of the scene - use top-down endogenous attention to actively look for the features and bottom-up exogenous attention to spot those areas of salience e.g. the colour red

Question 16

What is meant by efficient search?

Answer 16

“Pop-out” or parallel searching i.e. target is defined by salient attribute and can be found quickly, accurately and without effort
This occurs independent of items in the scene
Conscious attention joins the party once the salience has already been detected

Question 17

What is meant by serial/inefficient searching?

Answer 17

Target not FULLY unique i.e. some shared attributes with targets in the surroundings
Search is now effortful as must compare mental representation of target with everything in the scene
Response time increases as a function of number of items in the display

Question 18

What is the role of inhibition in active search (i.e. search using eye movements)?

Answer 18

RECAP: Foveal acuity means we have to move our eyes, obtain snapshots and stitch everything together to produce the illusion of being able to see a continuous image
We use attention to guide this process, and we use inhibition to stop ourselves from returning to a previously attended area that we have concluded as irrelevant for further attention
In experiments this inhibition of return is witnessed - slower to respond to target presented in previously attended area than a new but equidistant area

Question 19

What are the more modern theories of attention?

Answer 19

Moving away from idea of pre-attentive/attentive searching and thinking more in terms of efficient/inefficient - attention considered a continuous process
Characterisation depends on difficulty of target discrimination - how long, how many saccades needed etc

Question 20

What is the definition of efficient search?

Answer 20

Interaction between bottom-up salience and top-down attentional set based on intentions e.g. use bottom-up to narrow the attentional field and then use top-down to identify accurate target

Question 21

What does Duncan’s Integrated Competition Model suggest?

Answer 21

As our fovea can only attend to one place at once, there is competition for selection and this can be biased by features such as emotional valence of a stimulus
Evidence suggests that cognitive mechanisms of attentional selection work with regions of the brain such as the amygdala

Question 22

What evidence came from Rapid serial visual presentation tasks?

Answer 22

Faces similar in features but expressing different emotions
Rapid train of stimulus events - two faces separated by masks of jumbled faces
Recognition better at later lag times (capacity limits, attentional blink)
At the same lag, emotionally salient faces showed more accurate responses than neutral faces even at the early lags

Question 23

What is hemispatial neglect?

Answer 23

Neuropsychological syndrome associated with unilateral (most commonly on RHS) cortical lesions
Traditionally described by visuospatial defects - inability to orient towards/respond to visual stimuli in the contralateral visual field
Neglect can be object based i.e. regardless of location of object, can only see one side of it

Question 24

What are the areas most commonly associated with attention?

Answer 24

Temporoparietal junction and superior temporal gyrus

Question 25

What does the involvement of memory in this syndrome suggest?

Answer 25

Attention has an influence on post-attentional higher processing -in these patients it is not a visual attention deficit but rather a general breakdown of ability to prioritise and select information based on location i.e. they are purely unaware of the existence of the neglected side of space

Question 26

What is meant by “gradient of awareness”?

Answer 26

Suggests we have specialised brain circuits for selecting and prioritising information for subsequent processing, specific to each hemisphere

Question 27

What is meant by the cocktail party effect?

Answer 27

Describes the ability to focus one’s listening attention on a single speaker among a mixture of conversations and background noise
Also able to identify relevant salient information from background noise e.g. someone calling your name

Question 28

What psychological processes inform endogenous selection and how do these change with age?

Answer 28

Top-down attentional processes like memory, and basic sensory processing like audition - both decline with age

Question 29

What does hemispatial neglect tell us about how our brains represent the location of objects in the world?

Answer 29

We can represent object coherence relative to ourselves at any one time (egocentric)
Even when we move around we don’t lose where things are so we are also coding in an allocentric coordinate framework i.e. location of an object in relation to surrounding objects

Question 30

Why do we most commonly see left sided hemispatial neglect (from lesion on RHS)?

Answer 30

Right hemisphere is responsible for attention on right and left side, left hemisphere is only responsible for right
If the lesion occurs on the left, we still have the right hemisphere covering both sides so only partial neglect if any
If damage to right side however, only get left with a functioning attentional capability for the right side i.e. see left sided neglect