Topic 5: Attention

Question 1

what is attention?

Answer 1

a limited capacity to process competing options in which attentional mechanisms select, modulate, and sustain focus on information most relevant for behaviour

Question 2

what is the problem, importance, and challenge of attention?

Answer 2

P: allocate limited resources
I: prioritizing information
C: balance the need for selective focus to handle new situations

Question 3

Source: Exogenous vs. Endogenous

Answer 3

Exo: environmental, reflexive, automatic, “bottom-up”
Endo: in the mind, voluntary, intentional, “top-down”

Question 4

Target: External vs. Internal

Answer 4

Ext: sensory information in the environment
Int: mental representations in the mind

Question 5

Type: Overt vs. Covert

Answer 5

Overt: movement of the sensory surface
Covert: no actual movement

Question 6

Type: Transient vs. Sustained

Answer 6

Transient: momentary focus
Sustained: prolonged focus

Question 7

Type: Selective vs. Divided

Answer 7

Selective: one thing to the exclusion of others
Divided: multiple things simultaneously

Question 8

Dichotic Listening

Answer 8

when a person has headphones on, and different messages are sent to different ears. Person is told to pay attention to one ear or the other

Question 9

Cherry’s Early all-or-none filtering (Broadbent’s filter model)

Answer 9

low level gating mechanism can filter out irrelevant information before the completion of sensory and perceptual analysis (couldn’t report the content)

Question 10

Grey and Weddenburn’s Early Attenuation (Treisman’s attenuation theory)

Answer 10

meaning of unattended words are taken into account

Question 11

McKay’s Late Selection Model

Answer 11

all stimuli are processes through the completion of sensory and perceptual processing before selection occurs (meaning of the same word differed depending on what was played to the unattended ear)

Question 12

Strategic Control Model

Answer 12

top-down selection at early, middle, or late stages depending on the circumstances

Question 13

EEG

Answer 13

measures surface electric fields generated by post-synaptic potentials in dendrites of neurons

Question 14

Event-related potentials (ERPs)

Answer 14

the average of EEG signals at a specific time locked event (temporal precision plotted with negative up)

Question 15

Brainstem evoked responses (BERs) or Auditory brainstem response (ABR)

Answer 15

• series of small electrical brain waves that are elicited during the first 10 ms after onset of brief auditory stimulus
• activity in the auditory brainstem nuclei and thalamus
• no attentional stream

Question 16

Midlatency responses

Answer 16

• 10-50 ms after auditory sound

- early activity in the auditory cortex (A1) that effects attention

Question 17

P20-50 Attention Effect

Answer 17

in midlatency responses, an enhancement of activity in attention that supports the early-selection theories

Question 18

Late Waves

Answer 18

• continue for several hundreds of ms

- extending activity in A2 and A3

Question 19

Attentional Stream Paradigm

Answer 19

two or more segregated series of stimulus are presented in parallel, and subjects attend to one to perform a task (dichotic listening tasks)

• EPR of both are compared
• effect in mid latency and late waves, but not in BEPs

Question 20

Endogenous vs. Exogenous in Posner’s Spatial Curing Paradigm

Answer 20

endo: arrows; faster to respond to validly cued targets, slow to invalidly cued; accordance with early-selection models
exo: list flashes; respond faster to target presented in the cued location than the uncued

Question 21

Inhibition of return

Answer 21

in exogenously cued spatial attention paradigm, there is a slower behavioural response to a target stimulus present at the validly cued location later than 300ms after the cue

Question 22

what is the neural effect of a stimulus on a plot

Answer 22

positive signal at 100ms, then a negative one

Question 23

what is the difference in the spikes on neural plot between an attended EEG and an unattended EEG

Answer 23

attended has was more activity with bigger spikes

Question 24

Attention affect reentrant activity

Answer 24

following a stimulus of event, a process where activity is fed back to the same brain region that was activated earlier in the process (loops to get processes by higher areas again)

Question 25

there are greater effects on which visual cortical areas from attention on stimulus processing

Answer 25

greater in low-level (V2, V3, V4) than in V1

Question 26

monkey study in visual attention and V4

Answer 26

• visual cortical neurons fire strongest if a stimulus is in that cell’s receptive field, and has the right specific characteristics
• BUT there is a strong fire in attend vs. unattended even when the stimuli are the same

Question 27

Orientation turning curve

Answer 27

attention causes scaling of response depending on the orientation

Question 28

contrast sensitivity

Answer 28

if you present a stimulus that you can see, but not very well, attention increases how well you see it; spatial attention increase at lower an middle contrast levels where it would be more useful

Question 29

differences in contrast levels in contrast sensitivity

Answer 29

• low contrast: small response, small change
• medium contrast: medium response, big change
• high contrast: big response, small change

Question 30

visual attention in fusiform face area (FFA)

Answer 30

• FFA= neurons that respond to faces
• more activity when they are paying attention to faces than when they are passively viewing them, and even more than when they are paying attention to something else

Question 31

Pop-out

Answer 31

rapidly detected target stimuli where a single feature is different from the distractors

Question 32

Feature search

Answer 32

• pop out
• no sequential shifts of attention
• rapid
• in parallel
  salient characteristics draw attention
• same amount of time, regardless of how many distractors
• bottom up
• exogenous
• parietal then frontal

Question 33

Conjunction Search

Answer 33

• more than one feature difference
• increase distractors = increase time
• reaction time is doubled when the object is not there because we have to search every single object whereas when the object is there, we can stop once we found it
• slope = how much more additional time (ideal person is 50ms added per additional item)
• frontal than parietal

Question 34

Feature integration theory

Answer 34

a model of attention postulating that the visual perception system is organized as a set of feature maps, each proving information about the locations in the visual field of a particular feature
- attention is required to bind different feature into consciously experienced wholes in two stages

Question 35

two stages of feature integration theory

Answer 35

1. preattentive stage: analyzes what we see into literally features which does NOT require attention
2. focused attention stage combines all of them, and DOES require attention

Question 36

where does 1. attention based feature integration occur? 2. preventive feature extraction? 3. low-level sensory analysis?

Answer 36

1. posterior parietal cortex
2. extra-striate cortex
3. striate cortex

Question 37

why does conjunction search use the frontal lobe before the parietal lobe?

Answer 37

you have to bind features together, so the frontal/control parts of the brain have to be active first to search for the target in a systematic way

Question 38

what happens when someone has damage to the right inferior parietal lobe?

Answer 38

deficits in spatial attention to the left side of personal and environmental space (contralateral)

Question 39

T/F
those with unilateral (hemispatial) neglect have a deficit on their memory of one side of their personal and environmental space

Answer 39

false - deficit in attention, not memory. if someone points something out to them on the other side of their fields, they notice it, but they can’t notice anything on their own

Question 40

what is the role of frontal eye fields (FEFs)?

Answer 40

• eye movements are closely tired to visual attention, therefore if you stimulate FEFs, you have greater firing in V4 (but only when the stimulus occurs in that V4 neurons receptive field)

Question 41

T/F

stimulating FEF has the same effect on V4 as stimulating V4

Answer 41

true - stimulating FEF is kind of like manually turing on attention in the brain (only when there is a stimulus in the field)

Question 42

IPS/FEF attentional control network

Answer 42

endogenous; voluntarily choosing to direct attention somewhere in a top-down control

Question 43

TPJ/VFC attentional control network

Answer 43

exogenous; involuntary attention in a bottom up control

Question 44

What is change blindness?

Answer 44

changes in a picture or scene over time are not immediately apparent if not attended to (e.g. flicker paradigm)

Question 45

what is the source, target, and type of attention used in the flicker paradigm

Answer 45

Source = endogenous because you are voluntarily looking around trying to find what changing
Target = external because you are looking at a picture
Type = covert because your eyes are moving; transient because you are moving your eyes around the screen; selective because focus on each spot on the screen individually