lecture 1- models of attention

Question 1

What is meant by selective attention?

Answer 1

“The ability to focus on that which is important to the task at hand, while ignoring or suppressing task-irrelevant information”

Question 2

what are the answers to WHEN and HOW we attend to information?

Answer 2

WHEN = early or late selection models (pre or post-processing)
HOW = structure or capacity models (does system have structural limitations or limited capacity)

Question 3

explain Broadbent’s filter model

Answer 3

• information not attended to is filtered out before any processing such as identification (and therefore NOT processed)
• filter that focuses attention- structural limitation that stops us from attending to info not supposed to

Question 4

what is the evidence for the early-selection model?

Answer 4

• Cherry 1953: dichotic listening
• what can be reported of unattented speech = BASIC PHYSICAL CHARACTERISTICS (voice/noise, gender, if becomes same in both ears (channels))
• what can’t be reported of unattended = SEMANTIC MEANING (content of message, normal/reversed speech, language/language changes)
• finding: only material (and therefore semantic meaning) in selected channel processed -> early

Question 5

what did Broadbent and Cherry conclude?

Answer 5

• channel selection takes place (input from one channel processed at a time)
• there is a cost of switching (switching between channels takes time- 300-500ms)

Question 6

what are the elements of Broadbent’s model?

Answer 6

1. sensory store (store for physical characteristics)
2. filter (selection of what is to be attended to)
3. perceptual/meaning analysis (processing)
4. STM (where encoding happens)

Question 7

what does the early-selection model predict?

Answer 7

• when filter is focused on one channel, there should be no real processing beyond basic physical elements
• dual tasking is actually doing two things one after the other (involves channel switching)

Question 8

what is evidence against early selection and structural limitations?

Answer 8

• evidence of processing name in the unattended channel (still semantic info being encoded)
• 30% (Moray 1959, Wood & Cowan 1995)
• physiological response to words in non-attended channel that were pre-associated with shocks (even synonyms- Corteen & Dunn 1974, Von Wright et al. 1975)
• following coherent message when switched to ‘unattended’ channel (Treisman 1960)

Question 9

what is Treisman’s modified model?

Answer 9

• ‘attenuated not eradicated’ model
• unattended info not filtered out, but attenuated (turned down) prior to processing
• attenuator instead of filter at same point as early
• signal from unattended is considerably weaker
• BUT some stimuli are ‘louder’/’stronger’ so are processed when unattended
• e.g primed stimuli (name)

Question 10

explain the late-selection model

Answer 10

• all incoming info processed automatically to highest level
• all stimuli’s physical characteristics are processed, named and categorised in parallel
• filtering happens after meaning processing (at level of response)
• bottleneck is prior to response (still structural limitation)

Question 11

what is the evidence for late selection?

Answer 11

• strong evidence of processing of unattended messages
• participants use material from unattended channel to resolve ambiguous sentences (Lackner & Garrett 1972)
• stroop (both elements compete for response, causing interference)

Question 12

why is unattended information remembered?

Answer 12

1. filter is leaky (unattended info is identified/processed, then selection happens after)?
   OR
2. the filter is slipping (attention system slips and attends and processes to material it shouldn’t)?
   (2 = early selection -> still focusing on things, just wrong things)

Question 13

what are meant by capacity models?

Answer 13

• no structure bottleneck
• cognitive system has limited amount of processing capacity
• allocates bandwidth to tasks
• limitation is how much resource you have to spend
• any task demands a processing capacity, and performance is dependent on conscious allocation of capacity to task

Question 14

what does a tasks demand depend on?

Answer 14

1. difficulty (more difficult = less bandwidth available to )
2. individual expertise

Question 15

what does conscious allocation of capacity to a task (and therefore task performance) depend on?

Answer 15

1. enduring dispositions (habits and preferences)
2. momentary need
3. evaluation of demands on capacity

Question 16

what is the role of arousal on conscious allocation of capacity?

Answer 16

• too much arousal = reduced focus, more irrelevant details noticed
• too little = no real motivation
• increased levels can counteract capacity limits (determines bandwidth we have to spend)

Question 17

what is evidence for capacity models?

Answer 17

• dual-tasking
• do 2 tasks separately and then together
• peformance drops (accuracy/RT) when do them together -> dual task decrement

Question 18

what are two findings about dual-tasking?

Answer 18

• reading prose while writing to diction - 6 weeks of practive led to competence (Spelke, Hirst & Neisser 1976)
• two visual vs two auditory had larger dual task decrement than doing one of each (Treisman & Davies 1973)

Question 19

explain Lavie’s perceptual load theory

Answer 19

• resolves early/late selection debate
• combines idea of attentional capacity (early) and that attention is allocated automatically (late)
• system is limited, but will process everything until it runs out of capacity
• selective attention determined by perceptual load of task
• low demand (simple stimuli) = more info is processed (increased chance of non-relevant info being processed as attentional capacity spills over from relevant) (LATE)
• high demand (complex stimuli) = only focus on certain aspects as attentional capacity used up (non-relevant filtered out) (EARLY)

Question 20

describe the setup for the original experiment for Lavie’s perceptual load theory

Answer 20

• single letter OR line of different letters (low vs. high PL)
• say whether z or x is present
• compatible/incompatible/neutral distractor capital letter present in periphery
• incompatible distractors supposed to reduce performance (as Z is also processed as well as x)
• as interference of distractor causes response competition
• incompatible RT longer than compatible RT: COMPATIBILITY EFFECT

Question 21

explain the results of the original experiment for Lavie’s perceptual load theory

Answer 21

• prediction: increasing PL should reduce compatibility effect (as distractors not processed under high PL, leading to less interference)
• low PL: strong compatibility effect (large RT difference between incompatible and compatible distractor)
• high PL: no sig compatibility effect (similar RTs) -> attention captured by other letters, reduces interference from distractor

Question 22

what did Cartwright-Finch & Lavie 2006 find about inattentional blindness?

Answer 22

• inattentional blindness: not noticing task-irrelevant elements in the visual scene
• did same experiment as original but low PL = saying colour of line and high PL = saying which line was longer
• high PL had less participants noticing black square in corner
• high PL reduces compatibility effect and increases inattentional blindness

Question 23

what is the role of WM in load theory?

Answer 23

• WM controls attention (picking up on and responding to the right things)
• there are general cognitive control processes beyond the perceptual system
• even when distractors aren’t processed, they gain control of behaviour
• cog control processes maintains a clear distinction between relevant and irrelevant info

Question 24

what experiment was done to investigate WM loads role in interference?

Answer 24

• dual-task experiment
  1. given set of digits to remember during task
  2. task: categorising faces as congruent/incongruent (distractor task while holding numbers in memory)
• low WM = 0, 1, 2, 3, 4 seq given
• high WM = different sequence each time
  3. after categorising, asked to report seq

Question 25

what did the experiment investigating role of WM on interference find?

Answer 25

- high WM load increases impact of incongruent pictures/names (longer RT) - indicates increased interference under high WM load

Question 26

what are the two systems that determine selection attention and how does overloading each of them affect interference?

Answer 26

- cognitive load (active system- controlled processing): overloading increases interference - perceptual load (passive system- automatic processing): overloading reduces interference