3. Dissociations between behaviour and perception Flashcards
What is NCC?
It is minimal set of neuronal events necessary and sufficient for conscious experience
How would you define necessary condition?
Must be satisfied in order for consciousness to arise (example: for visual experience → properly working eyes - not sufficient however). Lesion studies inform us about necessary conditions for consciousness - but not about sufficient conditions
How would you define sufficient condition?
Condition that guarantees consciousness will arise (for consciosuness: ’’some sort of brain activity’’ - unresolved)
What is vigilance?
being awake (sleep - fainting - coma - anasthesia)
What is attention?
focusing of mental resources into specific piece of information (selection mechanism, selecting what is relevant and what not)
What is conscious access?
Fact that some of the attended information eventually enters our awareness and becomes reportable to others (in any way)
What does it mean that vigilance and attention are enabling conditions for conscious access?
They are necessary but not always sufficient to make us aware of specific piece of information
What is level of consciousness?
It is vigilance/wakefulness
For example: “patient not being conscious’’ (level of consciousness)
What is the content of consciousness?
It is the vividness of the conscious content
For example: ‘‘not being conscious of red light’’ (content)
What are main minimal contrast manipulations of consciousness?
- binocular rivarly
- masking
- crowding
- attentional manipulations
perceptual rivarly
there are pictures which can be interpreted in two ways, input doesn’t change but the focus of attention and interpretation changes
for example: direction of rotation of the sphere
can be studied with eye-tracking (to know what people see) and EEG (feedback system informs you when the switch happens)
bincular rivarly
one eye sees sth, the other eye sees sth else → the information is not fused! the images switch between each other
continuous flash suppression
stimuli in one eye is much stronger than in the other eye (one stimuli is high contrast, it changes all the time, interesting), the stronger stimuli always dominates your vision (you never see the other weaker stimuli)
can be used to investigate what information breaks through (manipulating weaker stimuli making it stronger, angry faces vs neutral faces)
Why is perceptual rivarly good/bad method to study consciousness?
→ it is generalizable to limited population - only those with intact vision (but there is also auditory version of this method) → lecturer argued that blind people have impaired visionary consciousness
what is characteristic of subliminal stimuli?
you cannot ever see it (even if the attention is on that stimuli)
What are types of masking
- backward (after stimuli)
- forward ( before stimuli)
- pattern (pattern overlays with actual stimuli)
- metacontrast (mask surrounds the stimuli)
What is crucial in masking paradigm?
Stimuli must be presented really briefly (40 ms) to make it unconscious
crowding
perceptual phenomenon where the recognition of objects presented away from the fovea is impaired by the presence of other neighbouring objects
attentional manipulations
attentional blindess -> you see the stimuli but sth else catches your arrention (Who did it? - video)
consciousness as IV
It is manipulated like in masking paradigm
Visible stimuli vs invisible stimuli
It influences the signal (f.ex. fMRI)
consciousness as DV
It is measured
Subjects need to decide if they saw the stimuli or not
Example: binocular rivarly (input is the same, no stimuli manipulation)
What is minimal contrast approach?
pair of experimental situations that are minimally different (physically) but only one of which leads to conscious experience, the other is not
conscious perception is experimental variable that changes even though the stimulus remains virtually constant
