Attention Flashcards
seperate attention networks for..
voluntary and involuntary attention
voluntary
- top-down
- endogenous
- dorsal frontoparietal network
welke gebieden bevat het voluntary network
superior parietal lobe (SPL), frontal eye fields (FEFs) and middle frontal gyrus (MFG)
involuntary
-bottom up
- exogenous
- right lateralized ventral frontoparietal network
- detection of behaviourally relevant, unexpected or highly salient stimuli
welke gebieden bevat involuntary
temporoparietal junction TPJ
inferior frontal gyrus IFG
middle frontal gyrus MFG
default mode network is..
internal attention, this region is active when a person is not focussed on the outside world.
welke gebieden bevat default mode
posterior cingulate cortex, medial prefrontal cortex, angular gyrus
oog movement is
overt
zonder oog is
covert
default mode is anti-correlated with ….
top down
disengage attention
problems when the cortical temporoparietal junction is damaged -> involuntary attention!
move attention
problems when the superior colliculi are damaged
engage attention
problems when the pulvinar of thalamus is damaged
contralateral neglect
attentional problems in the other field in vision. ignore stimuli, ,slow response, ignore objects on contralateral side, muscle on controlateral side is worse sometimes. deficits in spatial attention in contralateral visual field. dit is bottom up attention. meestal na damage to the right lateralized bottom up network.
you can make neglect patients see
if they use top-down attention, als je het aanwijst, they can see things. but spontaneously (bottom up) they do not see anything. this is the difference with blind subjects. dus neglect is niet sensory deficits, het is echt een attention problem!!!
dus kort wat gebeurt er bij neglect
damage to bottom up netwerk dus disengaging attention becomes impossible. dit kan je meten met posner cueing task.
neglect is often
temporary, but extinction remains. (niet nieuwe neurons ofzo, maar oefenen) dus bijvoorbeeld 2 vingers zien ze L niet, maar spoon and fork -> dan zien ze de vork wel
balints syndrome
simultanagnosia: problem with attending to more than one object.
optic ataxia: problems with reaching and grasping (oog hand coordinatie)
oculomotor apraxia: problems making voluntary eye movements to objects
–> when the entire top-down attention network in the parietal lobe is damaged.
biased competition
competition in receptive fields. if both stimuli fall with the RF of the neuron -> competition.
with both stimuli, activity is the average response to effective and ineffective stimuli (medium activation). het gaat hier dus om 1 neuron
shift from frontal to parietal from
controlling attention to responsing to target
top panel
use cue to shift attention
voluntary / intentional shifts of attention activate the …
SPL and FEF (oa prefrontal cortex)
top-down activity shifts from … to …
front (cue) to back (target)
activity shifts from the front to the back in …. attention
top-down!! dit weten
pop-out search uitleg + welke vorm van attention
The target has a unique color, shape, or orientation with respect to the distracters
bottom up, stimulus driven (search is easy and automatic, parallel)
conjunction search uitleg + welke vorm van attention
the target differs from the distractors on multiple features that need to be combined to find the target
top down, voluntary (you have to combined 2 features, which needs voluntary attention because it is more difficult)
involuntary attention welke regions eerst
parietal regions (LIP) activate first, followed by frontal regions LPFC)
voluntary attention welke regions eerst
frontal regions activate first (LPFC/FEF), followed by parietal regions (LIP)
invalid cues during the exogenous variant posner task activates…
activity in the right temporoparietal junction
wanneer hebben pop out and conjunction dezelfde reactietijd
als er maar 2 items zijn
pop-out search reaction time
altijd dezelfde reaction time, maakt niet uit hoeveel number of items in display. -> automatic, parallel
conjunction search reaction time
increasing slope: the more items on display, the longer the reaction time is. als de target er niet is duurt het nog langer. -> voluntary, serial
treisman
feature integration theory
feature integration theory
features are processed in different brain regions (in parallel). therefore differences in one feature are detected automatically. when features need to be combined to find the target: the brain areas need to communicate with each other. in need of voluntary attention! -> serial bottle neck -> when objects differ from more than one feature, visual search takes a long time.
corbetta and shulman theory
- Top-down, voluntary system (SPL,
FEF): Preparing and applying goaldirected
selection - Bottom-up, involuntary system (right
TPJ and IFG): Detection of behaviorally
relevant, unexpected, or highly salient
stimuli
The bottom-up system is a circuit
breaker: “Stop what you’re doing now,
direct attention to the environment
NOW!”
there is a causal effect of control areas on sensory areas
dus van front to back of the brain
FEF
frontal eye field: visual attention and eye movement
there is a causal effect of control areas on covert attention
frontoparietal network modulates attention and therefore perceptual performance.
top-down activity shifts from … to …
front (cue) to back (target)
top-down activity shifts from … to …
front (cue) to back (target)
dus samenvatting voluntary
Voluntary (top-down, endogenous) attention:
* Dorsal frontoparietal network
* Most important regions: superior parietal lobe (SPL), frontal eye
fields (FEFs), middle frontal gyrus (MFG)
dus samenvatting involuntary
Involuntary (bottom-up, exogenous) attention:
* Right-lateralized ventral frontoparietal network
* Most important regions: temporoparietal junction (TPJ), inferior
frontal gyrus (IFG), middle frontal gyrus (MFG)
hoe gaat voluntary attention door het brein
Frontal first, then parietal, then sensory.
hoe gaat involuntary attention door het brein
Sensory first, then parietal (right TPJ), then frontal. This system can shut down the voluntary attention system.
dus 2 patronen door het brein
voluntary: front -> back
involuntary: sensory -> parietal -> frontal (back -> front)
