Consciousness Without Attention?
Do we have conscious sensory experience of objects we don't attend to? On a rich view, we have virtually constant sensory experience in every sensory modality (for example, all day long, a peripheral experience of the feeling of our feet in our shoes). On a thin view, conscious experience is limited to one or a few things or regions in attention at any given time. This rich-thin dispute is substantive, not merely terminological, and ordinary folks (as well as psychologists and philosophers) seem to split about 50-50 on it (with some moderates). I worry that the issue may be scientifically irresolvable.
However, some leading researchers in consciousness studies (Block 2007; and [more qualifiedly] Koch & Tsuchiya 2007) have recently put forward an argument against the thin view that runs as follows. When one's visual attention is consumed with a demanding task and stimuli are presented in the periphery, one can still report some features of those stimuli, such as their "gist" (e.g., animal vs. vehicle). Similarly, when one is presented with a Sperling-like display -- a very brief presentation of three rows of alphanumeric characters -- one has a sense of visually experiencing the whole display despite the fact that one can only attend to (and report) some incomplete portion of it. Therefore, conscious experience outruns attention.
I believe this argument fails. In both cases, it's plausible to suppose that there may be diffuse attention to the entire display, the entire (say) computer screen, albeit with focal attention on only one part of it. Such examples may establish that consciousness outruns focal attention narrowly defined, but they do not establish that consciousness outruns some broader span of diffuse attention. When attending to a visual display on a computer screen one may not even diffusedly attend to the picture on the wall behind the computer or the pressure of the seat against one's back. The question is, are these consciously experienced when absorbed in the experimental tasks? The Block/Koch argument shines no light whatsoever on that issue.
[Update November 19: Ned Block emailed me to say that he thinks I'm oversimplifying his view. I did simplify the argument somewhat, and for brevity and convenience I used the Sperling example, which he mainly deploys for another (closely related) purpose, rather than using his own preferred example. But whether the above is an objectionable oversimplification is a further question. I emailed Ned back hoping for clarification on some key points but have not yet received a reply.]
[Update November 20: Ned Block has emailed me with a fuller reply (full text, with his permission, here). He explains that in his view consciousness only probably outruns attention and that "the evidence points toward" that fact; and he thinks this is better suggested by "inattentional blindness" type cases (where people don't report seeing even fairly large objects or property changes when their attention is primarily occupied in some distractor task) than in what I called "Sperling-like" displays (by which I meant complex displays shown too briefly to allow full report but with report enabled by a cue to some portion of the display either during the display or very shortly thereafter). He also points out that Koch & Tsuchiya, like he, say that "it is difficult to make absolutely sure that there is no attention devoted to a certain stimulus". Finally, he says that to the extent he makes a case that consciousness outruns attention, it is a "holistic" case based on a variety of evidence and theoretical considerations, not a single type of experiment.
When I originally wrote the post, I was less interested in the details of Block interpretation than in a certain form of argument which I have heard several times orally (including during a well-attended talk by a very eminent researcher), the argument taking the form described in the post; and Block and Koch & Tsuchiya are the most eminent people I've found recently saying things along those lines in print; but it's true that I should have more carefully stated their qualifications and hesistations.]