Attention

Question 1

What are the 6 types of attention?

Answer 1

1. Reflexive Attention (stimulus-driven)
2. Selective Attention (task-driven)
3. Orienting
4. Overt Attention
5. Covert Attention
6. Divided Attention

Question 2

What is “Reflexive Attention (stimulus-driven)?

Answer 2

Bottom-up processes where a sensory stimulus captures our attention (the orienting reflex)

Question 3

What is “Selective Attention (task-driven)?

Answer 3

Top-down ability to choose what to attend to

Question 4

How can you study Visual Selective Attention?

Answer 4

A participant fixates on the central cross, while stimuli are flashed to the left and right fields. Instructed to covertly attend to left field and ignore the right and vice versa. Then response to the same stimuli on the left visual hemisphere are compared when they are attended and ignored.

Question 5

What is “Orienting Attention”?

Answer 5

Turning one’s attention to something

Question 6

What is “Overt Attention”?

Answer 6

Orienting with body

Question 7

What is “Covert Attention”?

Answer 7

No motor movements

Question 8

What is “Divided Attention”?

Answer 8

Process different pieces of information simultaneously

Question 9

What are the four conditions in attention?

Answer 9

1. Attend
2. Unattend
3. Active
4. Passive

Question 10

What is the difference between Attended and Unattended conditions?

Answer 10

If one message is attended and the other is unattended, only the attended is remembered. Unattended is lost and all participants can report is the gender of the speaker.

Question 11

What is the difference between Active and Passive conditions?

Answer 11

Active: Pay attention to sounds
Passive: Ignore sounds/read a text/watch a video with sound turned off.

Question 12

What is the problem with contrasting active to passive?

Answer 12

You might be changing general arousal also. Therefore, dichotic listening is generally a good way to study attention - because only the focus of attention is changed.

Question 13

What 3 levels of observation show that attending to a stimulus leads to higher activation of those neurons?

Answer 13

1. In auditory and visual cortex
2. In subcortical stations (cochlea, midbrain & thalamus)
3. In non-invasive recordings (EEG, MEG, fMRI) & single-cell recordings

Question 14

How does attention change responses?

Answer 14

It enhances and reconfigures, temporarily, receptive fields in the sensory areas

Question 15

Describe a study on ERPs being enhanced by attention (Hillyard et al.):

Answer 15

(See Attention Lecture, Slide 13 for graph) The solid line represents the idealized average voltage response to an attended input over time, the dashed line represents the response to an unattended input. The amplitude of the N1 component was enhanced when attending to the stimulus compared to ignoring the stimulus.

Question 16

Who studied intracortical recordings from cortex?

Answer 16

Mesgarani & Chang (2012)

Question 17

How did Mesgarani & Chang (2012) study intracortical recordings from the cortex?

Answer 17

• Presented sentences to human epilepsy patients
• Took intracortical recordings from surface of human auditory cortex
• Method: Stimulus spectrogram reconstruction from neural population
• Responses: Measure neuronal activity and deduce what the stimulus was

Question 18

What were the conditions of Mesgarani & Chang’s (2012) study?

Answer 18

• First auditory stimulus only, first being attended to
• Second auditory stimulus only, second being attended to
• Both auditory stimuli, first being attended to
• Both auditory stimuli, second being attended to
  (In mixed condition, auditory cortex is responding as if the sentence being attended to is being presented alone)

Question 19

Who studied Attention Modulates Visual Cortex?

Answer 19

Hopfinger et al (2000)

Question 20

Describe Hopfinger et al’s (2000) study:

Answer 20

• fMRI study
• Attending to the left or right visual hemifield leads to increased activation in visual cortex of the contralateral hemisphere
• No effect in primary visual cortex (V1)

(Selective Visual Attention: Before the target is delivered to the dorsal frontoparietal network, attention also activates the visual cortex.)

Question 21

What parts of the brain control attention?

Answer 21

The cortex and midbrain

Question 22

Where is the midbrain located?

Answer 22

It sits on top of the brainstem, under the cortex.

Question 23

What part of the brain controls selective attention during complex behaviour?

Answer 23

Frontoparietal network (prefrontal and posterior parietal cortex)

Question 24

What does a midbrain network direct for surprising or highly salient stimuli which have a spatial location?

Answer 24

Directs spatial attention and gaze to stimulus location

Question 25

What is the thin layer of inhibitory neurons surrounding the thalamus called?

Answer 25

Thalamic Reticular Nucleus (TRN)

Question 26

What did Wimmer et al (2015) say about the prefrontal cortex (PFC)?

Answer 26

The PFC exercises attentional control via switching on individual cells in TRN. Activated TRN cells then supress signals in thalamus - PFC controls what sensory input make it to the cortex

Question 27

What part of the brain controls the selective visual attention?

Answer 27

Dorsal frontoparietal network

Question 28

What does the dorsal frontoparietal network do?

Answer 28

Active when attention is directed to a spatial location in expectation of a task-relevant stimulus

Question 29

What part of the brain controls reflexive attention?

Answer 29

Ventral Right Network

Question 30

What does the Ventral Right Network do?

Answer 30

It directs attention to stimuli with high salience
- Suppressed during selective attention tasks (Corbetta et al., 2000)

Question 31

Who studied control of auditory selective attention?

Answer 31

Hill & Miller (2010)

Question 32

Describe Hill & Miller’s (2010) study:

Answer 32

• During the cocktail party effect, a left-hemispheric network controls attention: the left inferior frontal gyrus (IFG) and the left superior parietal lobule (SPL)

Question 33

What plastic changes in the cortex does attention lead to?

Answer 33

1. Stimulus is in attentional focus
2. PFC activates nucleus basalis (NB)
3. NB releases acetylcholine (ACh)
4. ACh targets cortical neurons representing the stimulus
5. The connections of these neurons are strengthened via LTP (Hebbian learning)

Question 34

What is the superior colliculus called in non-mammalian vertebrates?

Answer 34

Optic Tectum

Question 35

What is the superior colliculus/tectum?

Answer 35

Highly-developed neural processor, does sensory discrimination and rapid decisions for motor actions necessary for survival and reproduction

Question 36

What are the layers of the superior colliculus?

Answer 36

• Upper layers: receive input from retina and visual cortex, respond to visual stimuli
• Intermediate layers: Input from all modalities and from most of the brain. This includes information about the salience and task relevance of the stimulus.
• Lower layers: motoneurons that direct eye saccades and other orienting movements

Question 37

What is each superior colliculus layer?

Answer 37

Topographic map of space in retinocentric coordinates
- An object/event with a spatial location activates neurons in a specific location on the map
- Activation of motoneurons in a particular location will initiate a saccade which shifts the gaze and attention onto that location

Question 38

Why is there competition for superior colliculus space map?

Answer 38

Only one location can win
- The highest priority stimulus suppresses activity at all other locations
- Superior colliculus can override cortex and shift attentional focus on its own