Lecture 10: Other Consciousness theories

Question 1

What alternate theory was first introduced by which handsome man?

Answer 1

Local Recurrency theory

Question 2

How are these two theories similar?

Answer 2

They both believe that the feedforward sweep isn’t for consciousness and that you can get unconscious behavioural effects driven by this unconscious feedforward sweep. Also that widespread recurrent interactions incorporating fronto-parietal cortices are related to reportable conscious percepts i.e conscious access.

Question 3

How do these theories differ in terms of conscious experience?

Answer 3

Conscious access reflects a selection of the sensory input, with attention. This means the conscious experience is not very rich, as attention selects from the original input and we only become aware of those (e.g spotlight of attention).

Victor argues that, Dehaene by studying conscious access, very often focuses on this attention-dependent small capacity stable working memory representation of conscious experience. But conscious experience is much richer.

Question 4

Describe an experiment which could illustrate poor conscious experience as suggested by Dehaene and GNWT

Answer 4

Sperling’s attentional cueing paradigm. In which 12 digits are displayed in rows of 4 and a tone or something else is sounded to inform which row the participant must report after the rows disappear. The participant could not name all 12 but paradoxically could name any row requested. In this paradigm when there is no cue, it suggests that the conscious access to the world is limited as the participant only report one part of it. However, when a cue is presented right after the letters were presented, subjects are actually good at reporting them.

Question 5

What is an alternate explanation of the results of Sperlings experimental paradigm

Answer 5

The reason why they couldn’t report all might be caused by working memory as it overflows.

Question 6

What does Lamme attempt to demonstrate in the study provided by the lecturer?

Answer 6

Lamme discusses whether the conscious experience is very rich or very poor, as the GWT suggests

Question 7

What was the procedure of Lamme’s study?

Answer 7

8 rectangles at different orientations are displayed around a fixation point for 500ms. A grey screen is then shown for 200-1500ms and the rectangles return but some has changed their orientation.

The participant must report whether the cued rectangle changed its orientation. In some trials the rectangle is cued after the orientation has changed (a), others before the orientation has changed (b) and the rest during the grey screen (c).

Question 8

What were the results of Lamme’s study

Answer 8

(a) had an accuracy of about 60% which was much lower than those cued before (b= 100%) (c = about 90%).

Question 9

How are these different conditions actually different tasks?

Answer 9

(a) is a working memory task, and shows that the capacity is ~4.
(b) is an iconic memory task, when the inter-stimulus interval is short. (not interesting to what we are talking about).
(c) is visual STM, when the inter-stimulus interval is longer than 500ms.

Question 10

What consclusions were drawn from these studies?

Answer 10

These results suggest that when we present a screen and then take it off, we have a detailed representation of that information, then when we cue specific stimulus of this display, we can bring that fragile information to our WM. But when we present a second screen afterwards, all that fragile information is washed away, but the item we brought to out WM is robust to being overridden. Therefore we can report the stimulus.

Depending on the types of experience, we could conclude the conscious experience is very limited or not. When we look at ‘a’ it looks very limited, when we look at ‘b & c’ it seems rich.

Question 11

How does Lamme use this to roast smelly Dehaene

Answer 11

Working memory is working with attention, has small capacity, stable representation, and robust to interference. Visual short term memory (iconic and fragile)is very large but easily overwritten by other stimuli. The transfer from iconic memory to working memory happens with attention.

Victor argues that, Dehaene by studying conscious access, very often focuses on this attention-dependent small capacity stable working memory representation of conscious experience. But conscious experience is much richer.

Question 12

Summarise the difference between Dehaene’s and Lamme’s views in regards to attention

Answer 12

Dehaene claims that attention gates conscious access and is thus limited. Consciousness depends on attention.

Lamme claims that attention selects from what is already conscious and thus consciousness is rich. Attention and consciousness are independent. Considers the preconscious stage of Dehaene, which is not yet reportable, as already conscious. He thinks we create a memory only for conscious information, so consciousness and memory are strongly related to each other than consciousness and attention (as Dehaene says).

Question 13

How does Lamme’s views on the brain activation required for consciousness differ to that of Dehaene?

Answer 13

Victor Lamme argues that an involvement of the frontal area isn’t needed, a local recurrent processing is already raising the conscious experience. Information goes from the visual cortex to the dorsal and ventral route, and then comes back as a recurrent feedback. And this is already where we are conscious of something. For example only IT and V1 is sufficient for conscious experience.

Dehaene thinks we need fronto-parietal global ignition for the information to reach conscious access. But Lamme argues only local recurrent interaction between between for example higher level visual cortex and lower level visual cortex, is sufficient for consciousness to arise.

Question 14

Describe feedforward processing according to Lamme

Answer 14

Imagining we have two different stimuli reaching the visual cortex, Stimulus A and B. And the brain is at a neutral state, meaning there is no memory related to these stimuli or anything like that. Then we get a feedforward of information leading to a specific response, either A or B on the image. Depending on which route was taken by the stimuli. When the feedforward reaches the frontal part of the brain, we can get unconscious responses in the PFC. Although at the same time visual areas engage in recurrent interactions. We get an initial feedforward of information, but at the same time when this reaches higher order areas, we get a response back, a recurrent process. In this case, we have phenomenal awareness of stimulus A and B in this case, and we have a conscious response when also visual AND frontal areas engage in interaction. Then we get access awareness

Question 15

How do these two theories compare after this feedforward sweep?

Answer 15

Here the views converge again: when we get this fronto-parietal and visual recurrent interactions, then we have conscious access of Stimulus A, but not Stimulus B, as only Stimulus A is engaged in this recurrent interactions. Dehaene would say Stimulus B is in a preconscious state, it didn’t reach global workspace but it was processed.

Question 16

What is meant by the term non-retinotopic?

Answer 16

Non-retinotopic basically means it’s stable, it’s not dependent on where in the visual field anything is presented and information is in WM. For retinotopic, the stimulus in in iconic memory so it is still accessible if only the attention was present.

Question 17

Summarise Lamme’s views in a couple of lines

Answer 17

If we have recurrency, so recurrent interaction, we have phenomenal consciousness. If we would add attention to this, then we get conscious access. So then we transfer phenomenal conscious experience to conscious access.

Question 18

What controversial idea does Lamme’s views raise?

Answer 18

There is such a thing as conscious perception that a human being cannot report, without knowing it we are conscious.

=>When there is local interactions, the frontal isn’t involved, we cannot act on that information. But Lamme says this still counts as conscious experience and calls it phenomenal consciousness. Even if we aren’t aware of the information and can’t act on it. Therefore the debate in the field is whether this actually counts as conscious or not.

Question 19

How does Lamme claim that there is error in Dehaene’s methodology?

Answer 19

They disagree on the neural signatures of consciousness, so what we should look at when we are looking for consciousness. Lamme says Dehaene focuses on the consequences of consciousness by measuring what the subjects report. And so he misses the true cause of consciousness and mistakenly incorporates the consequences in the NCC.

Question 20

What have the criticisms of Dehaene’s methodology resulted in?

Answer 20

Now people are looking into ways of measuring consciousness where we don’t have to ask questions to the subjects.

This is called “No-report paradigms” now.

Question 21

Name two popular experimental paradigms in consciousness research that have been adapted as ‘no report’ versions

Answer 21

Binocular rivalry and inattentional blindness

Question 22

Describe no report binocular rivalry procedure

Answer 22

They looked at the eye movements of the subjects to predict what they are experiencing without asking them about it. Because when we perceive the green stimulus our eyes respond differently then when we perceive the red stimulus. There are two conditions, one where subjects reported and the other where they didn’t.

Question 23

Describe the results of the no report binocular rivalry study

Answer 23

The results showed that in the report condition we can see the fronto-parietal activity, but in the no-report condition there is no activity in the frontal area. Even though we know subjects see the images and changes. Showed that the frontal activity was about decision making and reporting, rather than to merely looking at the stimuli and being aware of it.

Question 24

Describe the stimuli of the no report inattentional blindness study

Answer 24

There are eight large red dots on a red ring, inside is a large group of little rectangles and a fixation point. the circle moves one step clockwise at the same time as all of these little rectangles change their orientation. Occasionally a red circle dims a little and some of the rectangles form a square in the middle but these are subtle enough that if you are focusing on spotting one you likely wouldn’t notice the other.

Question 25

Describe the procedure of the no report innattentional blindness study

Answer 25

In the first phase, subjects weren’t informed of the square shapes that appear here and there. They were told to focus on the red circles, and indicate when one of the 8 dots changed colour.

In the second phase, subjects were told that there are these changes. So they know there are square patterns and there are random patterns. Now they were asked if they were aware of them, but they still didn’t have to report it.

In the third phase, they knew about the patterns again, but this time they were asked to report.

ERP’s were recorded when there is a random array of lines presented in the middle vs the square pattern in each phase.

Question 26

Describe the results of the no report innatentional blindness study

Answer 26

Phase 1: ERP’s over parietal cortices showed that there’s no difference between the two.

Phase 2: The ERP responses were very similar to phase 1.

Phase 3: This time the ERP results changed, and we see a P3. The time plot also showed the increase in gamma (P3) was present when they had to report the stimulus

Question 27

What conclusions can be drawn from this study?

Answer 27

The P3 and gamma response (signatures of consciousness) seem to correlate mainly with conscious reporting, not necessarily conscious perception. But opinions differ greatly on this matter.

Therefore, Lamme once again concludes that the frontal activity of the brain is mainly related to the consequences of consciousness. When we ask subjects to report stuff, these signals are confused with the NCC.

Question 28

To summarise (again lol) where do Dehaene and Lamme mainly differ in opinion?

Answer 28

They differ mainly in their opinion about the role of the prefrontal cortex (PFC) in consciousness. According to Dehaene the PFC is crucial for consciousness (because of it’s crucial role in “global ignition”), According to Lamme the PFC is only needed for reporting (and therefore is a consequence of consciousness not a cause.)

Lamme: recurrence is consciousness
Dehaene: Recurrence is preconsciousness (not reportable)
Dehaene and Lamme: Recurrence plus attention is conscious reporting

Therefore Dehaene and Lamme differ mainly in the definition they use for consciousness

Question 29

What is the central concept of Information integration theory?

Answer 29

There are five axioms of consciousness

Question 30

Name the five axioms of consciousness

Answer 30

Existence: Consciousness exists (intrinsically).

Composition: Consciousness is structured (each experience is composed of many elements).

Information: Consciousness is differentiated (each experience differentiated from other possible experiences).

Integration: Consciousness is integrated/unified (each experience is irreducible to components)

Exclusion: Consciousness is definite (each experience excludes other experiences).

Question 31

What does consciousness reflect according to information integration theory

Answer 31

Consciousness reflects the balance of integration and differentiation/specialisation. When we look at another diagram in which the nodes are connected in a patterned manner we see an optimisation of the information integration for the brain that is functionally specialised and functionally integrated. This results in a lower phi.

In one diagram where nodes are well, but almost randomly, connected, the nodes we see that there is differentiation, not every node is connected to the all same nodes. But there is also integration, so they still connect to each other to a certain extent. This results in a higher phi.

Phi is calculating the integration and differentiation balance, the connectivity profile of the brain. The higher the phi, the higher the level of consciousness. The quantification of the richness of experience.

Question 32

What is consciousness according to higher order thought theory?

Answer 32

Neural states of first-order networks are viewed as non-conscious representations that are rendered conscious when re-represented by the higher-order network involving areas of prefrontal cortex.