Lecture 14 - eye movements and attention

Question 1

What are the two types of eye movements?

Answer 1

1. smooth pursuit eye movement - vision is continuous
2. saccadic eye movement - where the eyes move rapidly from one stimulus to another, vision is disturbed slightly.

Question 2

What do early selection mechanisms of attention in the brain do?

Answer 2

influence the processing of sensory inputs before the completion of perceptual analysis.

Question 3

What do late selection mechanisms of attention in the brain do?

Answer 3

act only after the complete perceptual processing of the sensory inputs, at stages where the information has been recorded as semantic or categorical representation.

Question 3

What do late selection mechanisms of attention in the brain do?

Answer 3

act only after the complete perceptual processing of the sensory inputs, at stages where the information has been recorded as semantic or categorical representation.

Question 4

What evidence is there for early selection?

Answer 4

early auditory cortical responses are affected by attention.

Question 5

What are the 5 different types of attention?

Answer 5

1. exogenous attention - transient, bottom-up and automatic
2. endogenous attention - sustained, top-down, voluntary
3. spatial attention
4. feature based attention
5. object based attention

Question 6

Describe the test done for exogenous attention?

Answer 6

• participant looks at computer screen waiting for a target to click
• dots appear randomly in the left or right corner
• brain drawn to these dots as they are a ‘surprise’
• target then appears where the dots were and reaction time is faster as the brain was exogenously attentive to that area

Question 7

Describe the test done for endogenous attention?

Answer 7

• participants fixates on cross in the centre
• an arrow cue indicates which visual hemifield the participant should covertly attend to
• cue is then followed by a target in either correctly cued or incorrectly cued location

Question 8

Describe the biased competition model of attention.

Answer 8

• animal has a fixation spot
• a stimulus within the neurons receptive field is shown many times
• this stimulus can either be preferred or not preferred
• when both stimuli are presented at the same time an intermediate response is elicited = competition
• the competition is eventually won by the stimulus that is preferred

Question 9

What conclusion was drawn from the biased competition model of attention experiment?

Answer 9

neurons compete for processing resources
feedback from higher areas selectively boosts these neurons to process the stimuli at the attended location
these in turn suppress their competitors

Question 10

Where was activity when motion is attended to?

Answer 10

activity in lateral occipitotemporal regions (human MT/V5) was modulated

Question 11

Where was activity when colour is attended to?

Answer 11

activity in ventral area V4

Question 12

What 5 areas are involved in attentional selection network (directing and maintaining attention)?

Answer 12

1. DLF = dorsolateral frontal cortex
2. IPL = inferior parietal lobe
3. STS = superior temporal sulcus
4. PC = posterior cingulate cortex
5. MF = medial frontal cortex

Question 13

What are the 6 areas involved in stimulus/motor processing?

Answer 13

1. pre/post central sulcus
2. VLF = ventrolateral frontal cortex
3. SPL = superior parietal lobule
4. SMA = supplementary motor area
5. AC = anterior cingulate cortex
6. VC = visual cortex