Week 6: Attention & Performance

Question 1

What is attention?

Answer 1

Mental process of concentrating effort on a stimulus

Four interrelated ideas:
1. We are constantly confronted with more information than we can attend to
2. There are serious limitations in how much we can attend to any at one time
3. We can respond to some information and perform some tasks with little if any attention
4. With sufficient practice and knowledge, some tasks become less demanding of attention

Question 2

Focused (selective) attention

Answer 2

Select 1 input whilst ignoring all others

• EYE MOVEMENTS (central fovea is focus)
• HEAD MOVEMENTS (positions ears)

Question 3

Visual search task (Treisman)

Answer 3

Indicate as quickly as you can whether a particular target is present

* Takes longer and requires more attention when searching for a combination (or conjunction) of features

Question 4

Feature integration theory (Treisman & Gelade)

Answer 4

Two processing stages:

1. Basic features processed rapidly and pre-attentively in parallel across visual search
   - Targets defined by a SINGLE feature (Will remain quite fast to do even with more distractors added)
2. Slower serial process with focused attention
   - Targets defined by a COMBINATION (or conjunction) of features
   (Also with more distractors, i.e. more lines, it takes even longer)

Question 5

Illusory conjunctions

Answer 5

• No difficulty perceiving features on display
  
  • However, unsure how features are combined
  • Report illusory conjunctions (may remember the H and the X, but may not remember the colours/ switch the colours they were)

Question 6

Attention networks (there are 2) (Posner)

Answer 6

Exogenous

endogenous

Question 7

Exogenous network

Answer 7

• bottom-up
• stimulus-driven
• automatically
• attention
• PERIPHERAL CUES

Question 8

Endogenous networks

Answer 8

• top-down
• goal-directed
• controlled by expectations (base on existing knowledge)
• CENTRAL CUES

Question 9

Attention networks (Posner, 1980)

Answer 9

• Select the side a flash of light is presented
  – Left/right of a central fixation cross
• Flash preceded by a central cue:
  – Arrow correctly points to flash location (valid)
  – Arrow incorrectly points to flash location (invalid)
• Flash preceded by a peripheral cue:
  – Outline of shape in flash location (valid)
  – Outline of shape opposite side of flash location (invalid)

Question 10

Trials with Majority of cues valid

Answer 10

– Central cues = RTs faster for valid cues
– Peripheral cues = RTs faster for valid cues

• Separate exogenous and endogenous systems? NO
  – Expect that cues are reliable (i.e. correctly cue the correct location of the flash)

– Endogenous attention used when central cues present and controlled by expectations
– Exogenous attention used when peripheral cue present and stimulus-driven

Question 11

Trials with Majority of cues invalid

Answer 11

– Central cues = RTs same for both valid/invalid
– Peripheral cues = RTs still faster for valid trials

• Separate exogenous and endogenous systems - YES
  – Expect that cues (that are invalid) should be ignored (i.e. do not cue the correct location the flash)

– Endogenous attention used when central cues present and controlled by expectations
– Exogenous attention used when peripheral cue present and stimulus-driven

Question 12

Focused Attention - Auditory attention

Answer 12

• Lessons learned from vision applied to our sense of hearing
  
  • Select sounds of interest, while ignoring others
  • Must separate (or segregate) different auditory stimuli

Question 13

Cocktail Party Problem - Cherry (1953)

Answer 13

– How do we focus on one conversation at a time?
– Using physical differences (e.g. gender, location)
– Extract little information from unattended stimulus (weren’t focussing on before, but something has drawn our attention to it)

– Exogenous (stimulus-driven), as hear salient information in unattended stimulus

Question 14

Cross-modal attention

Answer 14

• Coordinate information from two or more modalities simultaneously
• Ventriloquism effect
  – Close together in time/space
  – Match expectations (so see sound to come from the puppet)
  – Example of visual dominance

Question 15

Cross-modal attention: McGurk effect

Answer 15

– Sound same in both clips (just moved mouth differently)
* Further evidence for visual dominance
– Input from vision influences auditory perception

The McGurk effect supports cross-model integration

Question 16

The development of cross-modal attention
(Maidment 2015)

Answer 16

Does visual information improve speech identification in children?
– Speech degraded to simulate cochlear implant listening

(one condition had the mouth moving, telling the children what to identify, others had just a still image) Is the message clearer with visual info too?

• The youngest children did not benefit from visual information
• Audio-visual gain increased with age
  Maidment et al. (2015)

Question 17

Divided attention

Answer 17

• Present two stimulus inputs at same time
  
  • Must attend and respond to ALL inputs
  • Also known as multi-tasking
  • Tells us the capacity of attention

Question 18

Dual-task performance

Answer 18

• What determines how well we can perform two tasks at the same time?– Similarity between tasks modality
  * e.g. visual vs auditory– Similarity between responses
  * e.g. manual vs vocal

Question 19

Automatic processing

Answer 19

• Practice makes perfect!
  
  • Assume that processes become automatic
  • Two major theoretical approaches
    1. Traditional approach (Shiffrin & Schneider, 1977)
    2. Definitions of automaticity (Moors & de Houwer, 2006)

Question 20

Automatic processing: Traditional approach

Answer 20

Controlled processes - SERIAL PROCESSING
– Limited capacity
– Require attention
– Used flexibly in changing circumstances

Automatic processes - PARALLEL PROCESSING
– No capacity limitations
– Do not require attention
– Hard to modify once learned
Parallel = can do at the same time

Question 21

Automatic processing: Definitions of automaticity

Answer 21

• Reject assumption that clear-cut distinction between controlled and automatic processes
• Four factors associated with automaticity
  
  1. Unconscious
  2. Efficient
  3. Fast
  4. Goal-unrelated
• Not always found together
  – e.g. can be partially conscious or fairly fast/slow

Question 22

Importance of attention

Answer 22

• Attention is important and helps us to:
  – Focus on a specific object to gain more information
  – Bind (or integrate) features together so we can perceive a coherent object
  – Ignore unwanted distraction
• Is our ability to perceive compromised in the absence of attention? ….

Question 23

Change blindness

Answer 23

Failure to detect changes in the environment

The ‘door’ study

Question 24

What causes change blindness?

Answer 24

No single (or simple) answer!
– Representations may be incomplete due to limited attentional focus

– Representations may decay or be overwritten

– Representations of pre-change stimulus may be limited to the unconscious

– Impossible to compare pre- and post-change

– Perceptual accuracy sacrificed so that we have continuous and stable perception of environment

Question 25

Inattentional bias

Answer 25

Fail to notice an unexpected, but fully visible item when attention is diverted to other aspects of a display

(e.g. the gorilla video)

Question 26

What causes inattentional bias?

Answer 26

• Depends on probability that unexpected object attracts attention
• Two factors of importance:
  
  1. Similarity of unexpected object to task-relevant stimulus
     o Black gorilla - ignore team dressed in black, whereas count passes between team dressed as white (so less likely to see it when focused on white)
     o More likely to see gorilla when counting passes between team dressed in black.
  2. Observer’s available processing resources

Question 27

Change blindness vs. Inattentional bias

Answer 27

Unlike inattentional bias, change blindness occurs because we FAIL to:
– Attend to the change location
– Encode the pre-change visual stimulus at the change location into memory
– Encode the post-change visual stimulus at the change location into memory
– Compare the pre- and post-change representations
– Recognise at the conscious level the discrepancy between the pre- and post-change representations
Jensen et al. (2011)

Question 28

Disorders of visual attention: Neglect (or spatial neglect)

Answer 28

– Lack of awareness of stimuli presented to side of space on the opposite (or contralateral) side to the brain damage (e.g. damage to right side of the brain may lead to less processing of objects through left eye/ side of an image)

* Typically involves right hemisphere damage
	– Left side of objects and/or objects presented to the left visual field are undetected

Question 29

Object-centred (allocentric) Neglect

Answer 29

Lack awareness of side of objects

Question 30

Subject-centred (ego-centric) Neglect

Answer 30

Lack awareness of entire side of visual field