L2: Limits Of Attention

Question 1

What is change blindness?

Answer 1

Failure to detect various changes in the visual environment

Question 2

Name 4 different ways to induce change blindness

Answer 2

• occlusion-contingent change (e.g door study)
• gap-contingent change
• saccade-contingent change
• blink-contingent change

Question 3

Name the two theories for explaining change blindness

Answer 3

• coherence theory (Rensink)

- theory of scene perception (Hollingsworth and Henderson)

Question 4

Outline the 3 stage coherence theory as an explanation for change blindness

Answer 4

Stage 1

-early parallel processing stage prior to focused attention extending across the visual field, producing representations of several objects which lack stability, these representations lack stability and are rapidly replaced by new stimuli at their location.

Stage 2

Focused attention produces a very detailed and longer lasting representation of one object, which allows the object representation to withstand a brief interruption. An object that is the focus of attention will be perceived as transformed when a stimulus replaces it

Stage 3

When focused attention is removed from an object its representation disintegrates and returns to the labile state it was in prior to becoming the focus of attention

Question 5

Outline theory of scene perception as an explanation for change blindness

Answer 5

• fairly detailed visual representations are formed of objects that are the focus of attention
• these representations are incorporated within a mental map coding the spatial layout of the scene. This information is stored in the long term memory

Question 6

Outline the differences between coherence theory and theory of scene perception

Answer 6

• main difference between the two is that coherency theory assumes that attention at the target object is required at the time the change occurs and that the representation of the object fades away rapidly when attention is moved elsewhere
• on contrast, scene perception theory assumes the object gets stored in long term memory, therefore a change can be detected even when attention is not on the changed object. Coherency theory does not assume a role of LTM

Question 7

Outline Hollingworth and Henderson’s (2002) research into change blindness

Answer 7

Procedure

-presented stimuli and recorded eye movements. Objects were changed when participants made a saccade (rapid movement of the eye between two fixation points)

Results

• change detection on,y occurs when the target has been fixated before the change
• participants are able to detect changes that occur just after they make a saccade
• number of intervening eye fixations after the change did not influence change detection (goes against coherency theory)
• type changes are detected better than token changes

Question 8

What is in attentional blindness?

Answer 8

Failure to detect an unexpected object appearing in the visual environment

Question 9

State two important factors in regards to noticing an unelected object in the visual environment

Answer 9

• the similarity of the unexpected object to the relevant task stimuli
• the observers available processing resources

Question 10

Outline Simon and Chabris gorilla experiment and the importance of similarity

Answer 10

• 50% of observers noticed the gorilla (black) when asked to count the passes made by the white team in the original study
• 42% noticed the gorilla when the colour of the gorilla and the team to attend to was coherent. In the second condition when the colours were not coherent the same statistic was 83%
• shows importance of similarity in terms of features

Question 11

Outline Most (2013) research and the importance of semantic category in inattentional blindness

Answer 11

-frequency of innatetional blindness was less when the unexpected object belonged to the same category as the tracked objects

Question 12

What did Richards (2012) find out about innattenional blindness?

Answer 12

-individuals high in working memory capacity were less likely than LOW scorers to display in attentional blindness. Therefor it seems in attentional blindness occurs due to insufficient attentional resources

Question 13

Eitam et als research into innattentional blindness

Answer 13

-IB can depend upon attentional set

Question 14

What is attentional blink?

Answer 14

The phenomenon in which the second of two targets cannot be detected or identified when it appears close in time to the first

Question 15

Outline Raymond and Shapiro’s (1992) research into attentional blink

Answer 15

• visual stimuli were presented in rapid fashion
• participants were asked to look out for letters coloured in red and to report at the end which letters these were (as well as look out for the letter ‘X’)
• masks (distractors) need to follow the target letter for attentional blink to work.

Findings

• participants found the task difficult when the second target letter (T2) was presented around 300ms after the first target letter (T1)
• showed no difficulty just detecting T1 or T2 when told to ignore T1
• T2 was relatively unaffected at very short delays and long delays

Question 16

What does attentional blink occur?

Answer 16

• in everyday life our brains are bombarded by a variety of sensory info and stimuli
• selective attention allows us to attend to the relevant cues, this filtering process however has temporal limits, which are revealed,and by the attentional blink

Question 17

Name the two main theories of the attentional blink

Answer 17

• interference theory

- Unified model

Question 18

Outline interference theory as an explanation of attentional blink

Answer 18

• T1, T2 and their masks are all encoded into a temporal buffer
• within the buffer the items interfere with each other
• Isaak et al varied the number if competing items that could occur after T2 (these were categorically similar to T2. The attentional blink rises with the number of competitors

Question 19

Outline the unified model as an eco,a nation of the attentional blink

Answer 19

-due to the mask following T1, increased attention is required to process T1, this leaves less attention for processing of T2, which leaves T2 vulnerable to decay or interference from other distractors

Question 20

What regions are involved with attentional blink?

Answer 20

-right inferior parietal and prefrontal regions

Question 21

Does the attentional blink occur in other modalities?

Answer 21

Yes, individually, but not when mixed