Task 4- Consciousness Flashcards
What is inattentional blindness?
people can miss obvious changes because they paid attention to something else
i) failure to notice a visual object or event, which ii) was in fact fully visible (in field of view) and iii) easily identified under circumstances in which it is consciously perceived
What are common change blindness tasks?
o viewers look at images on a computer monitor
o briefly leaving the screen blank, distracting participants, or interjecting visual noise (‘mudsplats’), suddenly makes this change very difficult to perceive
o change blindness can also occur in almost the opposite situation: With very slow changes in a stimulus without distractions
What are common attentional blink tasks?
o series of letters is presented rapidly one after the other on a computer monitor (this is called RSVP; rapid serial visual presentation) and participants need to report letters appearing in red
–> Since a red letter stands out, it grabs attention easily
What is the common result of attentional blink tasks?
o if a pair of targets are presented shortly after another, the second one is often missed
o first letter grabs your attention; attentional system “out of order” shortly after that (like a blink)
For which period of time does the attentional blink tasks work?
o Works not for between 200-400 ms after pictures; works for under 200 ms and more than 400 again
What is the cocktail party effect?
o Our attention systems allow us to voluntarily focus on what the person opposite us is saying. We can filter out all the competing, distracting, surrounding conversations
–> top-down/ endogenous
o ability to voluntary focus of what we choose to perceive and process
What is the lunch line effect?
o pronunciation of your name in another conversation manages to pull your attention away from whatever you currently paid attention to
–> bottom up attention/ exogenous
What is attention?
…is the prioritised processing of some inputs from a larger set of selectable items
Which types of attention include spatial/ space-based attention?
- Top-down attention
- Bottom-up attention
- Divided attention
- Covert attention
- Overt attention
What is top-down attention?
- Endogenous attention (goal-directed)
- E.g. cocktail party effect
- Voluntary focus of attention
- You control it; you actively select the inputs to prioritize
Which brain areas are probably involved in top-down attention?
Hierarchically higher-up brain regions such as frontal and parietal cortex are probably involved
How does the endogenous Posner Task work?
you fixate a cross, symbolic cue appears (arrows pointing to whichever side symbol is going to appear)
- -> if it appears on the side as predicted (valid cue): shorter reaction time
- 500 ms break
- only 25% of time: invalid cue
What is bottom up attention?
Exogenous attention (or automatic attention) (stimulus directed)
- e.g. lunch line effect
- Our attention can shift by the salience of stimuli on our environment
How does the exogenous Posner Task work?
- only 100 ms break
- NO arrows
- another cue that draws your attention that is not as attention- drawing (e.g. dots)
- 50% of time: invalid cue
What is divided attention?
We can focus un multiple things at the same time –> multitasking
What cost does divided attention come at?
You perform less well on both tasks
What does the difficulty of divided attention depend on?
depends on:
1) how constantly your attention is required for both tasks (one idea about divided attention or dual attention tasks is that participants actually rapidly switch attention between the two)
2) the relation and similarities between both tasks (more difficult when tasks are similar)
What is covert attention?
- allocation of attention without making eye movements
- attention could be shifted (on purpose or automatically) to the left or right, but the participants’ gaze never left the fixation cross
What is overt attention?
shift in attention is accompanied by a shift in gaze
Which types of attention does feature attention/ feature-based attention?
- Object attention
- Temporal attention
What is feature attention generally?
o Attention paid to features
o visual features: color, orientation, or intensity (brightness)
What is object attention?
- attention to one object rather than another
- e.g. task: house and face superimposed
What is temporal attention?
- Attention in time
- You expect something to happen in time (e.g. if a beat is missing)
Describe the experiment used to investigate temporal attention? (visual target with cues)
- experiment -> symbolic cue: indicates whether after that a visual target will appear early or late
- valid cues: reaction times shorter than when invalid cues presented -> stimulus onset asynchrony (SOA) (=after which time the stimulus appeared)
What is selective attention?
ability to prioritize and attend to some things while ignoring others
What is the filter theory of attention?
Sensory store -> selective filter (only attended stimuli pass through) -> Bottleneck: higher level processing Working memory
==> filter early and hard
What was the critique on the initial filter theory of attention?
Lunch- line effect not explainable
How was the filter theory of attention revised?
o Attenuation filter rather than selective filter: filtered stimuli weakened, but not blocked altogether; salient things can pass through bottleneck (can still explain lunch-line effect)
o filter: later processing stage than previously thought, so after the level of semantic (word meaning) processing
What is the Spotlight of Attention theory?
o You can change the size of your spotlight
o e.g. Find Waldo and when used reading a text
What does the Feature Integration Theory (Treisman) say about attention?
- Attenuation filter
- Pre-attentive stage of processing: can analyse only certain features already mentioned (including color, orientation, intensity in the visual domain); automatically and in parallel
- focused attention stage: features are combined into objects -> requires attention
- each feature is linked to a spatial location in the “Master Map of Locations”
What does the incorrect binding of features lead to according to Feature Integration Theory (Treisman)?
Illusory conjunctions –> when combining features that are not actually linked (e.g. blue M in box w/ green things)
What is the Resource Theory generally about?
focuses primarily on the allocation of attention in multiple tasks
What does the Single Resource Theory say?
- people have one common pool of attention, to be distributed among multiple tasks in whichever way they see fit
- if you run out, it’s out
- -> you are fundamentally limited
What does Single Resource Theory explain?
explains the degradation of performance
What does the Multiple Resource Theory say?
you have several resources of attention
What does the Multiple Resource Theory explains better?
better explains how some tasks combine better than others, depending on task parameters (such as sensory modality)
What is arousal?
refers to the global physiological and psychological state of the organism
-different levels
How do attention and arousal relate to each other?
Attention: more specific/not global concept of selective attention –> how you allocate attention at all arousal levels
What are attentional control networks?
- determined where and on what our attention is focused
- involve widespread, but highly specific brain networks
What is unilateral spatial neglect?
-Symptoms
- Vision not damaged, but is not aware
- not aware of their lesion
- > object vs space-based neglect
How does neglect and attentional control networks relate?
Neglect= when attentional control network is damaged in only one hemisphere
Which kind of lesion is found in people with neglect?
Due to unilateral lesions of the parietal, posterior temporal, and frontal cortex or due to damage in subcortical areas including the basal ganglia, thalamus, and midbrain
Which side of the brain is damages usually in neglect ?
More severe and more common when it is on the right side
What is extinction (neglect)?
failure to perceive or act on stimuli contralateral to the lesion (contralesional stimuli) when presented simultaneously with a stimulus ipsilateral to the lesion (ipsilesional stimulus)
- > bias to your damaged side
e. g. right damage -> left side neglected and right side attended
What are the 3 main symptoms of Balint’s Syndrome?
- Simultanagnosia
- Ocular apraxia
- Optic ataxia
- -> unable to perceive several objects in space
What is lesioned in patients with Balint’s syndrome?
bilateral occipitoparietal lesions
What is simultanagnosia?
difficulty perceiving the visual field as a whole scene e.g. when the patient saw only the comb or the spoon, but not both at the same time
What is ocular apraxia?
deficit in making eye movements (saccades) to scan the visual field, resulting in the inability to guide eye movements voluntarily
What is optic ataxia?
problem in making visually guided hand movements
What is spatial attention controlled by generally?
controlled by a mixture of stimulus-driven and goal-directed mechanisms
What happens neurally in selective attention?
may mediate cortical excitability in the visual cortex through a network that includes the posterior parietal cortex, the dorsolateral and superior prefrontal cortex,-and the pulvinar nucleus of the thalamus
What is the DAN primarily concerned with?
spatial attention
What is the VAN primarily concerned with?
non-spatial aspects of attention
What is the dorsal attention network also called?
Frontoparietal Attention System
What does the DAN reflect?
- goal-directed control of attention -> voluntary
- maintenance of attention
Which kind of cortex does the DAN influence?
-What does this kind of cortex do?
influences activity in visual cortex -> how salient object Is compared to surrounding
-shifting attention also without making eye movements
What are 3 key cortical nodes involved in the DAN?
frontal eye fields (FEF), intraparietal sulcus (IPS), superior parietal lobule (SPL)
What are attentional shifts correlated with?
correlated with significant changes in the activity of parietal neurons
What is the IPS(=Intraparietal sulcus) in humans concerned with?
location and saliency of objects
What does the right VAN exert?
Exerts stimulus-driven Control
–> disengages and reorientates Attention
What are three features of the VAN?
- Involuntary
- No topographic map
- strongly lateralized to the right hemisphere
Which areas does the VAN include?
TPJ, MTG and IFG
What are the superior colliculi responsible for in attentional networks?
changing eye movements
What is the pulvinar of the thalamus responsible for in attentional networks?
covert spatial attention and filtering of stimuli
Which kind of neurons can be found in the pulvinar of the thalamus?
-visually responsive neurons that exhibit selectivity for color, motion, and orientation
What is the goal-directed dorsal (frontoparietal) attention network primarily concerned with?
- concerned primarily with the control of spatial attention and the saliency of objects
- enables us to maintain attention on the current goal
- orientation of attention –> Where?
- shifts attention
What is the stimulus-driven ventral (frontoparietal) system primarily concerned with?
-essential for disengaging/reorienting our attention
-involuntary
- tells (!) dorsal system to move attention somewhere else
==> circuit breaker
e.g. when you realise invalid cue in experiments
What is the subcortical network finally primarily concerned with?
contributes to arousal, eye movements, filtering input and shifting and orienting of attention
What are the results of Egly’s object attention experiment?
Shorter reaction time when in same block/object due to object based attention
Similarity of Posner’s and temporal attention task
when valid cue –> reaction time is shorter
What happens if VAN damaged?
Nothing would tell u to shift the attention
What happens if DAN damaged?
You could not focus on one conversation or one thing!
