Task 5- Consciousness Flashcards
What did participants have to do in Watanabe’s study?
Participants lie in fMRI scanner and look at a target and a suppressing annulus
What happens if both targets was projected in one eye and when each was projected into a different eye in Watanabe’s study? What about consciousness?
- If both projected in one eye, the target (a visible grating) was visible -> C
- when each was projected into a different eye, the target became invisible (continuous flash suppression) -> NO C
What was the target and the non-grating in Watanabe’s study?
-What did they have to do if there was a red and a blue letter?
- Target: grating
- non-grating: letter
- ->red: attend to grating
- ->blue: attend to letter
How was attention in Watanabe’s study manipulated?
Participants were asked to attend to grating or to a letter
What was measured by the fMRI in Watanabe’s study?
Tracked hemodynamic activity of neurons in V1: attending to visible or invisible grating or attend away from the visible or invisible grating
What were the results of Watanabe’s study?
-When did the BOLD signal change?
o Bold signal didn’t change due to visibility or invisibility of target
o BUT paying attention to target increased BOLD signal (no matter if visible or invisible target) -> you can attend to stuff without becoming aware of it
When was consciousness measured in Watanabe’s study?
at stimulus-onset
What was the result of the study by Maier et al (described in Watanabe’s study)?
- What was recorded?
- What led to different brain signals?
- Do V1 neurons directly contribute to C?
o Monkeys: recorded V1 neurons
o Perceptual awareness and selective attention lead to different brain signals
o Greater attentional BOLD activity than BOLD activity related to visibility
• Visual attention and consciousness are related to different neural mechanisms
• V1 neurons do not directly contribute to C
What is Lamme’s theory about?
- there’s conscious and unconscious inputs
- attentive selection process operates at an independent stage
- attention determines whether a (conscious) report about stimuli is possible
- -> we are ‘conscious’ of many inputs but, without attention, this conscious experience cannot be reported and is quickly erased and forgotten
What is the role of attention in Lamme’s theory?
- without attention conscious experience cannot be reported and is quickly erased and forgotten
- Attention -> gatekeeper
How does Lamme explain change blindness and inattentional blindness?
failures of conscious memory, not consciousness
What are the two types of sensory memory?
retinotopic, fleeting form (iconic memory) and a more durable non-retinotopic form (working memory)
What does attention determine in regard to awareness?
- determines whether we go from phenomenal to access awareness or from iconic to working memory
- attention independent of awareness or memory
What was the result of the study with blocks (Figure 1) that was explained in Lamme’s article?
o Experiment with blocks
o Perform better when line pointing to block that is gonna change (condition b)
o As long as cue shown before second stimulus shown, you remember it correctly (condition c)
In which way is attention a selection process according to the neuroscientific perspective (discussed in Lamme’s article)?
Attention is a selection process where some inputs are processed faster, better or deeper than others, so that they have a better chance of producing or influencing a behavioral response or of being memorized
How does attentional priming work?
processing of a stimulus will leave a trace of activated and inhibited neurons
- > can last for a variable amount of time
- the processing of subsequent stimuli might benefit from this trace if the two stimuli share properties (such as retinal position) => attentional priming
What is a feed forward sweep (FFS)?
-Example of visual areas
earliest activation of cells in successive areas of the cortical hierarchy
-V1 responds after 40 ms
-after 80 ms: most visual areas are activated
-at 120 ms visual activation can be found in all cortical areas, including motor cortex
What is recurrent processing (RP) and when does it start?
As soon as the FFS has reached an area, recurrent interactions between neurons within that area and neurons that have been activated earlier at lower levels can start
What happens in backward masking in terms of FFS and RP?
Backward masking (40 ms): evokes selective feedforward activation in visual and non-visual areas and motor cortex --> recurrent interactions are suppressed!
What is necessary for motion awareness?
feedback from MT to V1 is necessary (-> RP)
How is attentional selection described by sensorimotor processing?
Attentional selection is how sensorimotor processing is modified by the current state of the neural network, shaped by genetic factors, experience and recent events (memory)
How does phenomenal experience originate?
originates due to recurrent interaction between groups of neurons
Who does phenomenal awareness seem to share neural mechanisms with?
seems to share neural mechanisms with iconic (sensory) memory and access awareness with working memory
Which type of awareness does local recurrent processing lead to?
phenomenal awareness
Which type of awareness does widespread recurrent processing lead to? Why?
psychological/ access awareness -> can be reported because attention was paid to it
