week 5 early and late attention

Question 1

The Meaning of “Attention”

Answer 1

-Brain’s ability to self-regulate input from the environment
-Used in two senses in psychology:
I. Sustained Attention (Alertness)
II. Selective Attention

Question 2

What is Sustained attention (alertness):

Answer 2

Related to psychological arousal (continuum from drowsy, inattentive to alert, attentive)
Problem of vigilance: performance declines over a long watch (radar operators, quality control inspectors, etc.)

Question 3

What is Selective Attention

Answer 3

we are limited in the number of stimuli we can process.
We attend to one stimulus at the expense of others. People have limited capacity systems – we don’t treat all stimuli equally.

Question 4

The Cocktail Party Problem origin

Answer 4

Cherry 1953
® In a crowed environment, we can ‘pick out’ one conversation from background noise
“Picking out:” processes take sound energy at ear, translate to understanding
Translation is selective (stimuli not all treated equally)
-Cherry was interested in what happens to unattended messages in this scenario

Question 5

the cocktail party Dichotic Listening and Shadowing

Answer 5

-the headphone play different sound in each ear (Dichotic Listening)
-Cherry asked participants to listen to two simultaneous passages of speech (known as dichotic listening), asking participants to attend to one passage (the attended channel) and ignore the other (the unattended channel).
-attending to a passage by speaking the attended channel out loud (shadowing)
- ask what is the unattended channel about

Question 6

the cocktail party Dichotic Listening and Shadowing result

Answer 6

Unattended Channel:
-No memory for unattended message
Switch from English to German: not noticed
Switch from male to female: noticed
Reversed speech, play backwards : “something queer”
Switch from voice to 400 cps pure tone: noticed

Question 7

Conclusion from unattended message

Answer 7

Only superficial (physical) features perceived
Semantic content not analysed (language, meaning)
Preattentive processes vs. focal attention

Question 8

Preattentive processes vs. focal attention (Neisser, 1967)

Answer 8

Sensory (physical) features processed preattentively
Meaning requires focal attention
Plausible: aware of unattended stimuli only superficially in cherry’s study

Question 9

How Do We Select the Attended Message?

Answer 9

Binaural presentation (Cherry): both ears receive both messages, same voice, differ only in content
Very difficult!
Source localisation in space important cue (phase differences in arrival times at ear)

Question 10

A Criticism of Cherry

Answer 10

Interested in what’s perceived, Cherry looked at what’s remembered
Confounds perception and memory
May be perceived then forgotten?

Question 11

Filter Theory (Broadbent, 1958)

Answer 11

Attention acts as a filter to select stimuli for further processing
-biological role is to prevent overload of cognitive system

Question 12

Filter theory indept

Answer 12

-Attentional selection is based on simple physical features (location in space, voice etc.). Those simple features/properties are extracted (processed) pre-attentively –not requiring access to the limited capacity channel.
® Meaning is extracted in a limited capacity channel, which translates sensory information (sound) into conceptual understanding. This can only be done on the contents of one sensory channel at a time.
® Meaning requires access to the limited capacity channel, and can only be extracted if the stimulus is attended to.
® The selective filter precedes the limited capacity channel, protecting it from overload. There is only one arrow going from the filter to the channel – suggesting that we can only process one thing at a time.
® All stimuli are stored briefly in the short-term store (STS) – which stores unanalysed sensory material. This is known as iconic (visual) or echoic (auditory) memory.
® Sensory information decays quickly if not selected.

Question 13

Evidence for Filter Theory

Answer 13

Spit span attention
Dichotic digit stream: when people were instructed to recall digits in temporal order, they only got 3-4
digits correct
Ear-by-ear recall: 6 correct (all the digit in one ear to another)

Question 14

Explaination for Spit span attention

Answer 14

This is because ear-by-ear recall only needs 1 filter switch, whereas 5 switches are needed to follow
temporal order. Switches take time, which decays the short term store trace

Question 15

The failure of filter theory

Answer 15

“Dear Aunt Jane” experiment (Gray & Wedderburn, 1960)
Split-span experiment with meaningful material
L: Dear Three Jane
R: Six Aunt Five
Preferred recall follows semantic context, not presentation ear

Question 16

Moray (1959) dichotic task and name

Answer 16

Had participants complete a dichotic listening task, where they listened to two passages of continuous speech (one to the left ear and one to the right). Participants were asked to shadow only one of these passages.
® However, he embedded the person’s name in the unattended channel.
® He found that people often detected the occurrence of their own name on the unattended channel.

Question 17

Early selection theory (Treisman, 1961)

Answer 17

® Sensory analysis takes raw wave form and converts it into sound, allowing you to distinguish one sound from another.
® Understanding sound involves semantic analysis, where sounds are made meaningful by activating stored knowledge. It is intimately connected with our stored knowledge of the meanings of language in long-term memory

Question 18

The Early vs. Late Selection Debate

Answer 18

Early:
Sesory analysis > Filter > sematic analysis
Late:
Sensory analysis > sematic analysis > Filter

Question 19

Attenuation model – a feature of early selection (Treisman, 1961):

Answer 19

® Suggests that the filter partially blocks (attenuates) unattended stimuli – akin to ‘turning down the volume’ on the unattended channel.
® This is in contrast to Broadbent’s model, which suggests that the filter completely blocks unattended stimuli.
® Argued that the filter is biased by context & message salience. Highly salient stimuli (e.g. one’s name) & semantically related material (e.g. Dear Aunt Jane) get through the filter, shifting attention

Question 20

Evidence for early selection (Treisman & Geffen, 1967):

Answer 20

® Got people to perform a dual task (doing two things at once) – a shadowing task and a detection task. The word tap was embedded in unpredictable places in both the shadowed and ignored passage.
® This method got people to indicate what they perceived as they perceived it (rather than at the end), avoiding the methodological issues in Cherry’s procedures which confounded perception & memory.
® Found that the percentage of correct detections was higher on the shadowed channel, but was not zero on the unattended channel. This is consistent with the
idea of a filter that attenuates unattended stimuli instead of blocking it altogether

Question 21

Criticism of Early Selection

Answer 21

Complexity of filter: Needs to respond to semantic context, distinguish related from unrelated stimuli – simpler alternative?
Late selection: Differs in where filter is located, after LTM instead of before LTM

Question 22

Late Selection

Answer 22

ES and LS theories agree recognition needs (a) encoding, (b) access to LTM
LS theory: All stimuli access LTM, not sufficient for awareness
ES theory: LTM activation = conscious awareness
LS theory: need to pass filter for awareness

Question 23

Late Selection (Norman, 1968)

Answer 23

Bottom-up and top-down selection mechanisms
Bottom-up, stimulus driven
- top-down, selection by “pertinence” (relevance to task)
Need both kinds of activation to get through filter, otherwise decays

Question 24

Evidence for Late Selection mckay

Answer 24

Semantic processing on unattended channel
McKay (1973)
Shadow:
“They threw stones towards the bank” (ambiguous)
Ignore:
“ … … … … … river” or “ … … … … … money”, related to the attended channel
-People where unaware of the task.
® McKay found that the semantic content of a word on an unattended channel can bias people’s recognition performance on the attended channel (the unattended word was used to resolve ambiguity on the attended channel). This is only possible if the unattended channel was processed up to the level of meaning

Question 25

Evidence for late selection: Von Wright, Anderson & Stenman (1975)

Answer 25

® Classically conditioned a galvanic skin response (GSR) to target words. Following this conditioning phase, participants were asked to shadow a passage and to ignore a second unattended passage. Target words has a classically conditioned GSR were embedded in this passage.
® Found that there was semantic activation (GSR) in response to these words, even in the absence of attention. This could only be possible if these words were processed to the level that their semantic category could be identified