Our Assistant Editor, Daniel Tippens, asks Professor Ned Block, of New York University, about his work on the relationship between phenomenal consciousness and access consciousness. This is part II of that interview, you can find Part I here.
SciSal: Something I remember I was thinking about a lot is some of the methodological concerns with the phenomenal overflow debate. Something you mention in one of your papers is the methodological puzzle of consciousness. You already mentioned it briefly, but could you please tell us a little more about what this methodological puzzle is?
Block: It’s that our only data — or not our only data, but our basic data — is what people say, if people say, I saw it, or they give you a numerical ranking [on a scale of 1-10 how certain are you that you saw it?] But then we somehow have to leverage this data and go beyond what they say they saw to try to figure out whether there are things that they saw — consciously saw — that don’t get into their cognition. So we have to use cognition to somehow go beyond cognition. And that’s what’s so tricky and difficult. 
SciSal: Yeah. And could you tell us a little bit more about your general methodological strategy for overcoming this? Obviously you’ve mentioned already some of the experiments that you used. But you have kind of a specific methodological picture of how to integrate evidence to come up with a theory of consciousness despite the methodological puzzle.
Block: Well, it turns out the way that it’s been most fruitful is to be clever about what you ask people, or to not ask them until after the experiment. So one of the really quite cool forms of evidence is evidence from a number of papers by a guy at Reed College named Michael Pitts. His technique is actually very simple: he looks at brain imaging data for when people are seeing things. But he doesn’t ask them the crucial questions until the experiment is over. He has these experiments, they’re called dual task in the sense that there are two different things that the subject is doing. So of course in many of the cases, they don’t know they are doing two different things.
One of his experiments involved a ring with some dots on it. And the official task was to say when one dot got a little bit bigger. And it would be a very difficult task. People were really working hard at that. And then in the background there are some lines that might make a figure or might not. So he put people in a brain scanner, and then after the end — after 240 trials — he gave them a big questionnaire about what they saw in the background.
Some people were aware of, say, a square in the background, and other people weren’t. And what he found is that awareness of the square correlated with activity in the back of the head. So one of the crucial issues here is whether visual consciousness is found in the visual areas in the back of the head or whether it involves a global neuronal workspace I mentioned in the front of the head. Previous work had suggested it involved the global neuronal workspace. But it turns out, the real reason for that is that the people were reporting consciousness.
So the global neuronal workspace activation came from the reporting of consciousness rather than from consciousness itself. Using his technique, he was able to show that the actual consciousness came before the global workspace activation. The kind of imaging involved is one that’s very temporally fine-grained. 300 milliseconds after the stimulus, there is this activation in the visual areas. And that’s what correlates with the later conscious reports, not the global neuronal workspace activations. That only happens later, between 300 and 500 milliseconds. So you have to avoid reports, because once you have reports, you contaminate the question.
SciSal: Right, interesting. So there is this other philosophically interesting methodological issue, and the claim here is that the burden of proof lies on the rich view of consciousness. 
SciSal: I took it that there is some kind of appeal to simplicity to motivate their argument, right? Why should we say that there’s more to consciousness than simply what’s in working memory, what we have access to, unless we have evidence to show for it?
SciSal: I’m just curious, I don’t think that you would agree that the burden of proof…
Block: No, no, I don’t think there is any burden of proof. I think what you need to do is to look at the data and try to figure out whether consciousness does or does not overflow cognition. So I don’t think anybody has the preference, I don’t think either view is simpler. So maybe consciousness does overflow cognition; maybe it doesn’t. They are equally simple.
SciSal: Let’s just try and find out, right?
Block: Let’s just try and find out, yeah.
SciSal: Another question that comes to mind has to do with the self-consciousness part. If you’re right that you can be phenomenally conscious of more than you have access to, it seems to give us kind of a different picture of phenomenal consciousness than we previously thought. I can be phenomenally conscious of something without, in any kind of robust sense, being aware of it, i.e having access to it.
SciSal: And so in some sense it seems like it’s not really my experience anymore, right? After all, I don’t have access to it any more than someone else does. But most people tend to have the intuition that if you are phenomenally conscious of it, one defining feature of phenomenal consciousness is that it’s yours and that you are aware of it in some way that others aren’t.
SciSal: Now, there are different accounts of how to kind of satisfy our intuitions on this. And I was hoping you could tell us a little bit about your solution to this.
Block: So first of all, I don’t think it’s counterintuitive or unintuitive that your awareness of yourself can be suppressed in very engrossing conscious experience. One experience that many people have is often called flow. When you’re really very much engrossed in an experiential task you know people report that they flow into it. There’s a kind of flow of experience, and they lose conscious awareness of their selves while still having conscious awareness of what’s going on. People sometimes report this in sports or listening to music. So I think that’s a very intuitive thing.
And there’s evidence of this. It’s collected by neuroscientist Rafi Malach. What he did was he gave people a very demanding but routine sensorimotor task, where they had to classify pictures. And he found that there was suppression of the frontal cortex during that. A similar suppression of the frontal cortex happens in dreams, where people lose a certain amount of awareness of themselves in a sense. It’s still experiences that are yours, but the monitoring isn’t there.
SciSal: I see. That’s an interesting point, that in our ordinary daily experiences we seem to lose awareness of phenomenally conscious states in demanding tasks. So essentially we shouldn’t feel strange about having phenomenal consciousness of something we don’t have access to.
SciSal: Moving on to the next topic, some people think that attention might be necessary for binding features together. So to make it clear, when I’m looking at you, you have a bunch of features that are bound together — you know, your hair to your face, color to your face, nose to your face etcetera. And attention is the thing that binds these together to give a whole form object. Without attention, there’s kind of just a jumbled assortment of features that don’t really have a form, right? In other words, you can’t have the feature-bound face of Ned Block without attention.
SciSal: So just to be clear, would you think that the phenomenal experiences we have outside of accessibility would be more like jumbled features as opposed to whole-form experiences of like Ned Block’s face out there?
Block: Well, it’s an interesting question. The theory that attention is required for binding is usually attributed to the psychologist Anne Treisman. But if you look at her work carefully, you’ ll see that she never says attention is necessary for binding. Even her original paper on this mentions another kind of binding, what she calls top-down binding, where cognition does the work.
It is an interesting question as to whether people really ever have unbound experiences. There is a kind of brain damage which has been suggested as a situation in which people have them, and it’s called Balint’s syndrome. The reason people suggest that is those people often do a lot of mis-binding. You can give them a, you know, a green circle and a red square. And they’ll often say it’s the square that’s green and the circle is red. So they mis-bind a lot. But what nobody really knows is whether they have some kind of unbound experience. It’s never been something that anybody has ever verified, although people do talk about it. It’ll be an interesting fact if there aren’t unbound experiences because that suggests that binding is part of what it takes to have a conscious experience, if there aren’t any. And that’s something that people have suggested as well.
SciSal: So I’m just personally curious, do you have an intuition one way or the other on this question?
Block: I wouldn’t be surprised if it turns out that binding is actually crucial to having the experience at all and that we don’t have experiences without binding to at least the place and the time.
SciSal: For visual experiences in particular?
Block: For visual experiences, yeah. For smell experiences, you don’t have that same kind of spatial orientation. So it may not be a general feature of experience.
SciSal: Right, I recall you also mentioned emotions in one of your papers.
Block: Yeah, conscious emotions. They don’t have a location either.
SciSal: Well okay, I think those are all the questions that I had for you today.
Block: Oh, well thank you very much.
SciSal: No, thank you. I appreciate it. And hopefully we can do this again sometime in the future.
Block: Sure, that’d be fun, yeah.
Dan Tippens is Assistant Editor at Scientia Salon. He received his Bachelors of Arts in Philosophy at New York University. He is now a research technician at New York University School of Medicine in the S. Arthur Localio Laboratory.
Ned Block is Silver Professor of Philosophy, Psychology and Neural Science at New York University, where he arrived in 1996 from MIT. He works in philosophy of mind and foundations of neuroscience and cognitive science and is currently writing a book on attention. He is a past president of the Society for Philosophy and Psychology, a past Chair of the MIT Press Cognitive Science Board, and past President of the Association for the Scientific Study of Consciousness. The Philosophers’ Annual selected his papers as one of the “ten best” in 1983, 1990, 1995, 2002 and 2010.
 Consciousness, accessibility, and the mesh between psychology and neuroscience, by N. Block, Behavioral and Brain Sciences, 2007.
 The Overflow Cup Runneth Over, by R. Brown, 16 February 2012.