Attention I Flashcards
we are typically confronted with a … amount of information
vast
attention can select… of sensory input for further processing steps such as memory, attention etc.
only a subset!
what is this called: a lot of information, of which you can completely miss a proportion
sensory competition
change blindness
if you put your spatial attention on something, because your attention resources are limited -> you can only attent to a subset of the sensory input, therefore we may be completely blind for unattended portions of the input.
chapter 6 open vraag lezen!
oke
which structure is important for arousal
thalamus
function reticular nucleus
sheet around thalamus: can gate information (high arousal) or block information (low arousal: sleep/coma/drowsy)
what regulates the excitability of the reticular nucleus
the reticular formation (soort tracts die vanuit de medulla komen)
attention and arousal relatie
attention =/= arousal, but you do need arousal for attention! attention is selective, arousal is not selective.
selective attention function
enabling us to process relevant input, thoughts, and actions. also to ignore or suppress information that is irrelevant or distracting.
voluntary is…
endogenous, intentional, top-down
involuntary is …
exogenous, stimulus driven, bottom up (attention goes there without you having to attent)
overt
attention is directed to the same location as the eyes (motor function!), komt vaak voor in everyday life
covert
attention is directed somewhere where your eyes are not going.
- vb exp: location of covert spatial attention, you can direct attention at a different point than the point of fixation (bv punt op het scherm)
neuroscience approaches on attention:
- effects of attention on stimulus processing (back of the brain to more anterior areas)
- control of attention in the brain (regions of the brain that are involved in control)
main question in attention science
how does attention modulate sensory input? at an early or late level?
early selection
some information is selected early, based on physical stimulus features (color, spatial location, pitch), and non-attended information is not processed at all.
late selection
full high-level semantic (meaning) processing of non-attended information, the selection occurs only afterwards.
attenuation
(attenuated = verzwakt)
Not all info is kicked out that you do not attent to, but it is attenuated. only salient information is fully selected. but the un attended information CAN reach higher levels.
flexible selection
attention can influence selection at multple levels: early vs late selection depends on the task.
wat is de conclusie over early/late en hoe wordt deze vorm genoemd
depends on the situation = flexible selection
dichotic listening task
information to one ear needs to be voiced, shadowed. and the other ear needs to be ignored.
dichotic listening test is evidence for…
early selection: mensen weten niets meer van het ignorede oor, no meaning is processed. they also do not notice a change in language or repeating a word over and over. they do however notice difference in gender, or human voices etc. therefore: no meaning is processed.
conclusie early selection
without attention, no higher level semantic processing (dus no meaning!)
problem for early selection theories
the cocktail party effect (je kan het eigen naam horen als je in een andere conversatie zit). this captures your attention, which should not be possible. therefore late selection models were developed. -> implication early selection = Effects of attention should occur early in the visual/auditory system and nonattended stimuli should not reach higher brain regions.
late selection
attentional selection occurs only after full processing of the auditory or visual information.
implication of late selection theory
Effects of attention occur late in the visual/auditory system and non-attended stimuli can reach higher brain regions.
P200 wave
Event Related Potential: a spike occurs 150-250 ms after a stimulus is presented.
P1
The P1 is called the P1 because it is the first positive-going component (when also using a mastoid reference point) and its peak is normally observed in around 100 ms, after presentation of a visual stimulus.
(The P20-50 for auditory and P1 for visual spikes occur almost immediately when the stimulus arrives in the primary auditory/visual cortex)
wat is het effect van attention op auditory and visual
attention modulates the primary auditory cortex, not subcortical structures.
attention modulates the primary visual cortex, and also subcortical structures: LGN.
selection early or late debat is geholpen door…
neuroscience (eeg, fmri)
EEG on selection
auditory attention: P20-50 components (20-50 ms after stimulus), attention is already boosted to the stimulus. from the very first moment infomration arrives in the primary auditory cortex.
visual system: information also travels very fast, with P1 (P100).
Dit is dus bewijs voor early selection.
fMRI on selection
auditory: attention modulates the primary auditory cortex AA!, but not the subcortical structures.
visual: attention modulates primary visual cortex V1 activity, and even subcortical structures (LGN).
the effects get stronger the higher you go up in the system!
which effects are weaker, early or late
early effects are weaker than late effects. therefore, selection of task irrelevant information depends on task difficulty.
difficult task leads to
early selection: irrelevant information is kicked out very fast, because there are no resources left to spend on these irrelevant things
easy task leads to
many resources left, dus late selection.
early ook when …
one exactly knows what to attend to
late ook when …
one does not know what to attend to (looking for a friend not knowing where she is and what she is wearing).
dus wanneer early en wanneer late:
early: difficult task (want resources needed for the task), when one knows what to search for (colour)
late: easy task, when one does not know what to search for (friend in crowd)
late ook when …
one does not know what to attend to (looking for a friend not knowing where she is and what she is wearing).
ERP
when you average the responses of an EEG stimulus, you get event related potentials, characteristic waves that are representative of the behaviour to your stimulus. they have specific names. they emerge from the brain stem.
there is a RANGE of early effects to late effects -> sometimes attention is modelates early, and sometimes late.
oke
posner cueing task (GOED KENNEN)
spatial task.
shows that attention can be: voluntary or involuntary. but they are in constant competition!
study voluntary attention in the posner cueing task
valid cue: arrow point to location where the taget will appear.
neutral cue, arrow point to both loccations where targets can appear.
invalid cue: arrow points to wrong location.
3 important facts for posner cueing voluntary
- Participants have a choice to use the cue or not: Voluntary
decision to move attention to the left or right or to divide attention - Cue validity matters: If the arrow is not predictive of where the
target will appear, people stop using the arrow - It takes time before attention can be moved: Participants need a
least 200 ms to move attention to the left or right. If there is less than
200 ms between cue and target, no cueing effects
posner cueing task 2 cues
endogenous cues: pijltje richting de goede kant, dan moet je dus echt goed kijken naar waar hij heen wijst = endogenous, voluntary, top down, intentional.
exogenous cues: heet ook wel peripheral cue. er komt een lichtje als cue; je aandacht gaat daar automatisch heen, hoef je geen moeite voor te doen = exogenous, bottom up, stimulus driven.
eXogenous = boX
results of posner cueing voluntary
- Valid cue: Response time (RT) is faster and
accuracy is higher compared to neutral condition. - Invalid cue: RT is slower and accuracy is lower
compared to neutral condition. - However – these effects are only present if there is
at least 200 ms between cue and target. - However – these effects are only present if cue
validity is high enough (at least ~70%, 80% is most
commonly used).
verschil voluntary en involuntary bij posner task
bij involuntary is het een flash of light, dus je hebt niet de keuze of je kijkt of niet.
three important factors to remember involuntary cues
participants have no choice to use the cue or not. and the cue validity does not matter, even if the cue is predictive, the attention is drawnt o the cue anyways. the timing is also different. the benefits is juist beter onder 200ms, en dan krijg je minder goede resultaten (=inhibition of returen)
3 cues bij posner cueing task involuntary
Two conditions
1. Valid cue: Flash of light appears at location where
target is going to appear
2. Invalid cue: Flash of light appears at the other, nontarget
location
3 important facts for posner cueing task involuntary
- Participants have no choice to use the cue or not: Cue
forces attention involuntarily to move to the left or right - Cue validity does not matter: Even if the cue is not
predictive of target location, attention is still pulled to the
location of the cue - Cue-target timing determines attentional effects:
Benefits of valid cues with less than 200 ms between cue
and target. When more than 200 ms, then less effect!
This effect is called “inhibition of return.”
wat is inhibition of return
if there is more than 200 ms between involuntary cue and the target, even the valid cues have less effect on the reaction time.
meest belganrijke resultaten posner cueing involuntary
- Valid cue: Response time (RT) is faster and
accuracy is higher. - Invalid cue: RT is slower and accuracy is lower.
- However – the valid cue effect is only present
when there is less than 200 ms between cue and
target - However – the valid cue effect changes from a
benefit to a performance decrement (inhibition of
return) if there is more than 200 ms between cue
and target
wat is het effect van attention op auditory and visual
attention modulates the primary auditory cortex, not subcortical structures.
attention modulates the primary visual cortex, and also subcortical structures: LGN.
dus wanneer early en wanneer late:
early: difficult task (want resources needed for the task), when one knows what to search for (colour)
late: easy task, when one does not know what to search for (friend in crowd)
dus wanneer early en wanneer late:
early: difficult task (want resources needed for the task), when one knows what to search for (colour)
late: easy task, when one does not know what to search for (friend in crowd)
3 important facts for posner cueing voluntary
- Participants have a choice to use the cue or not: Voluntary
decision to move attention to the left or right or to divide attention - Cue validity matters: If the arrow is not predictive of where the
target will appear, people stop using the arrow - It takes time before attention can be moved: Participants need a
least 200 ms to move attention to the left or right. If there is less than
200 ms between cue and target, no cueing effects
exogenous
Stimulus-driven, involuntary, bottom-up. A stimulus literally draws attention (“capture of attention”). Followed by
inhibition of return for that stimulus location.
endogenous
Goal-oriented, voluntary, top-down. By choosing what to attend to, information is processed better and
faster at the expense of other information.
welk deel van het brein is voor welke soort aandacht
ventral: stimulus driven, bottom up, endogenous (what) -> first 200 ms
dorsal: top-down attention, exogenous (where) -> after 200 ms
attentional blink task
stimuli (bv letters) are shown in rapid succession (within 10 ms) and inbetween them are targets (numbers). participants have to report the targets. -> rapid serial visual processing.
attentional blink results
T1 is reported perfectly. T2 less.
T2 is reported good if it occurs right after T1, or if there is more than 500ms between t1 and t2.
T2 reporting is bad if it occurs within 250-350 ms after T1. Dus je hebt een soort blink waartussen je even niet goed processsed. attention is still busy processing T1, therefore T2 is missed.
Attention has no influence on
auditory processing in subcortical
structures.
oke
attentional stream paradigm
* P20–50 effects of attention: This is the
very first moment that information arrives
in primary auditory cortex.
* N1 effects of attention also present:
Entire auditory cortex is engaged about
100 ms after stimulus onset.
* However: No difference between normal
and deviant tones in these early ERP
components.
Early components (P20-50 and N1) are
amplified by attention (“early selection”),
but for all stimuli to the same extent.
* Late components of attention (P300)
amplified for deviants/targets compared
to standard stimuli (“late selection”).
* P300 enhancement only for deviants/
targets in the attended ear, indicting that
deviants in the unattended ear are
filtered out (“early selection”).
oke
However: Mismatch negativity in a modified
attentional stream paradigm
* Discovery: Deviant stimuli (pitch, intensity,
timing) also produce a mismatch negativity
(MMN) 150–200 ms after their occurrence.
* MMN is related to perceptual discriminability.
* MMN for deviants in the attended and in the
unattended ear: Automatic “early” feature
analysis of all auditory input (“late selection”).
* But amplified MMN in attended ear: Early
feature analysis is nevertheless susceptible to
attentional modulation (“early selection”).
oke
covert spatial attention on P1 and N1
als de covert spatial attention goed is -> larger P1 en N1. P1: Reflects V2, V3, V4 activation; N1:
Reflects visual and parietal regions
covert spatial attention on fmri
Attention towards a location enhances
neural activity (contralateral hemisphere;
upper field → ventral, lower field →
dorsal)
attentional blink task has … selection
late
RF and visual hierarchy
receptive fields get bigger when you go up the visual hierarchy, therefore multiple objects can fall within the RF of a neuron. -> competition for representation in receptive field -> attention may solve this.
competition in receptive field:
- Effective (preferred) stimulus for neuron:
Strong activation - Ineffective (non-preferred) stimulus for
neuron: Weak activation - If both stimuli fall within the RF of the
neuron → Competition - With both stimuli, activity is the average
response to effective and ineffective
stimuli (medium activation)
which area is attending to motion
v5
which area is attending to colour
v4
attentional resources determine stage of attentional seleciton in areas….
- Easy task: Task-irrelevant motion activates V5
- Hard task: Task-irrelevant motion no longer
activates V5
Attention to one type of object
reduces processing of other types of objects.
Attentional enhancement and suppression
simultaneously!
oke
attentional stream paradigm evidence for early and late selection
proof for early selection because P300 (large longer latency wave that peaks at about 300 ms) enhancement is seen for deviant targets in the attended ear only, and early components of ERPs are amplified for all stimuli equally
and late selection evidence because p300 in attended ear is seen only for deviant targets, but not for standard stimuli
