Lecture 3: Attention

Question 1

Inattentional blindess

Answer 1

=failure to process information that is not attended

-looking for something else means can fail to attend to other information, tells us attention is very selective

Question 2

Bottom up selection

Answer 2

‘Stimulus driven mechanisms’
perception begins with the stimulus itself. Processing is carried out in one direction from the retina to the visual cortex, with each successive stage in the visual pathway carrying out ever more complex analysis of the input.

Question 3

Top down selection

Answer 3

‘Goal driven mechanisms’
perception that is driven by cognition. Your brain applies what it knows and what it expects to perceive and fills in the blanks, so to speak.

Question 4

Selective attention: Stroop effect

Answer 4

‘Name the colour of the ink’
-much slower when the colour and word are incoherent
• You need to inhibit the ‘wrong’ response-that’s what slows us down in the Stroop effect

Question 5

Selective attention: Visual search

Answer 5

Search for a single feature = rapid, effortless, automatic
Search for a conjunction of features = slow, effortful, controlled

• When searching for a single feature it stands out from the group of items (Blue letter)
• When features are conjoined (Blue L) then it takes much longer to search and the number distractors has a dramatic impact
• Treisman& Gelade(1980) argue that one uses parallel processing (fast) and the other serial processing (slower, effortful)
• Many factors impact search speed (e.g. nature and number of distractors)

Question 6

Divided Attention

Strayeret et al (2003) Cell phone study

Answer 6

Group 1: Drive in simulator & brake unexpectedly
Group 2: Drive + talk on hands-free phone at the same time & brake unexpectedly

Results:
• During low-traffic conditions (when driving is not too demanding), Group 2 took slightly longer to press brake
• During high-traffic conditions (difficult task/driving conditions), Group 2 took much longer to press break

Difficult when:
• Tasks are difficult
• Tasks are similar (e.g same modalities) eg McLeod (1977) contour following and pitch identification
• When both tasks require controlled attention

Easier when:
• Tasks are simple
• Tasks are dissimilar (e.g different modalities) McLeod (1977) – verbal labels and contour following
• When at least one of the tasks does not require controlled attention
• Tasks are practiced

Question 7

Attention and the brain: The posterior attention network

Answer 7

• Parietal lobe
• Visual search of stimuli
• Neuroimaging studies: increased blood flow associated to visual search
• Brain damaged: patients able to notice only stimuli in the left or right side

Question 8

Attention and the brain: The anterior attention network

Answer 8

The anterior attention network

• Frontal lobe
• Inhibiting automatic responses

Question 9

Disorders of attention

Parietal lesion

Answer 9

(right hand side of brain)= (hemi)neglect
-people are slower to experiment one half of their world compared to the other, and often disregard one half entirely as if it ceased to exist

Question 10

Disorders of attention

ADHD

Answer 10

=neurological development disorder, affecting 3-5% of children

Main symptoms:

• always in motion, cannot stop talking
• very impatient
• easily distracted
• have difficulty maintaining focus on one task

General reduction of brain volumes
But especially in the left prefrontol cortex
->frontal lobe dysfunction (inattention, hyperactivity, impulsion)