In this elegant and tightly argued target article, Ned Block seeks to persuade us that phenomenal consciousness routinely “overflows” cognitive accessibility. By this he means that we can (and do) have experiences even in cases where we lack the kind of access that would yield some form of report that such and such an experience had occurred. The case Block makes for such an apparently hard-to-support judgment rests on a “mesh” between psychological results and work in neuroscience. The psychological data seem to show that subjects can see much more than working memory enables them to report. Thus, in the Landman et al. (Reference Landman, Spekreijse and Lamme2003) experiments, for instance, subjects show a capacity to identify the orientation of only four rectangles from a group of eight. Yet they typically report having seen the specific orientation of all eight rectangles. Working memory here seems to set a limit on the number of items available for conceptualization and hence report.
Work in neuroscience then suggests that unattended representations, forming parts of strong-but-still-losing clusters of activation in the back of the head, can be almost as strong as the clusters that win, are attended, and hence get to trigger the kinds of frontal activity involved in general broadcasting (broadcasting to the “global workspace”). But whereas Dehaene et al. (Reference Dehaene, Changeux, Naccache, Sackur and Sergant2006) treat the contents of such close-seconds as preconscious, because even in principle (given their de facto isolation from winning frontal coalitions) they are unreportable, Block urges us to treat them as phenomenally conscious, arguing that “the claim that they are not conscious on the sole ground of unreportability simply assumes metaphysical correlationism” (sect. 14, para. 9; italics in original). That is to say, it simply assumes what Block seeks to question – that is, that the kind of functional poise that grounds actual or potential report is part of what constitutes phenomenology. Contrary to this way of thinking, Block argues that by treating the just-losing coalitions as supporting phenomenally conscious (but in principle unreportable) experiences, we explain the psychological results in a way that meshes with the neuroscience.
The argument from mesh (which is a form of inference to the best explanation) thus takes as its starting point the assertion that the only grounds we have for treating the just-losing back-of-the-head coalitions as non-conscious is the unreportability of the putative experiences. But this strikes us as false, or at least premature. For underlying the appeal to reportability is, we suspect, a deeper and perhaps more compelling access-oriented concern. It is the concern that any putative conscious experience should be the experience of an agent. The thought here is that we cannot make sense of the image of free-floating experiences, of little isolated islets of experience that are not even potentially available as fodder for a creatures rational choices and considered actions. Evans (Reference Evans and McDowell1982) rather famously rejects the very idea of such informationally isolated islands of experience. According to Evans, an informational state may underpin a conscious experience only if it (the informational state) is in some sense input to a reasoning subject. To count as a conscious experience an informational state must:
[serve] as the input to a thinking, concept-applying and reasoning system: so that the subject's thoughts, plans, and deliberations are also systematically dependent on the informational properties of the input. When there is such a link we can say that the person, rather than some part of his or her brain, receives and processes the information. (Evans Reference Evans and McDowell1982, p.158)
The real point here is (or should be) independent of Evan's appeal to conceptualization. What matters, rather, is that the information must be available to the agent qua “reasoning subject,” where this may be unpacked in many different ways, not all of them requiring full-blown concept-use on the part of the agent (see, e.g., Bermúdez & Macpherson Reference Bermúdez and Macpherson1998; Hurley Reference Hurley1997). Evans' insight is that the notions of conscious experience and reasoned agency (here very broadly construed) are deeply intertwined: that there are non-negotiable links between what is given in conscious awareness and the enabled sweep of deliberate actions and choices available to a reasoning subject. Such a story opens up a different way of interpreting the Sperling (Reference Sperling1960) and the Landman et al. (Reference Landman, Spekreijse and Lamme2003) results. In these cases (we suggest) subjects report phenomenally registering all the items because information concerning each item was, at that moment, available to be deployed in the service of deliberate, reasoned, goal-directed action. Such momentary potentiality is not undermined by the (interesting and important) fact that the selection of a few items to actually play that role then precludes the selection of the rest.
Contrariwise, Block argues that a subject like G.K. can be having an experience of a face and yet it be impossible for him to know anything of this experience. Block takes G.K.'s phenomenal experience to be constituted by recurrent processing in the fusiform face area. We believe that G.K. can be consciously experiencing a face only if this experience is at least momentarily poised for use in reasoning, planning, and the deliberate selection of types of action. Recurrent processing in the fusiform area will no doubt prove to be among the conditions necessary for realizing a state that plays this causal role.
The contents of conscious phenomenal experience, if all this is on track, must be at least potentially available for use in the planning and selection of deliberate, stored-knowledge–exploiting, and goal-reflecting and goal-responsive, actions. Block's just-losing coalitions fail to trigger winning frontal coalitions and hence fail to be in a position to contribute their contents in this manner to the full sweep of the agent's deliberate acts and choices. It is this fact (rather than the more superficial indicator of unreportability) that should motivate our treating the contents of the just-losing coalitions as non-conscious. If this is correct, then the staging post for the argument from mesh is called into question. Until the considerations concerning links between experience and rational agency are more fully addressed, it remains unclear whether the kind of “fit” to which Block appeals can really favor his conclusion over our own.
ACKNOWLEDGMENTS
Thanks to Matthew Nudds, Tillmann Vierkant, and the participants in the Edinburgh Philosophy, Psychology, and Informatics Reading Group for stimulating discussion of the target paper. This commentary was prepared thanks to support from the AHRC, under the ESF Eurocores CNCC scheme, for the CONTACT (Consciousness in Interaction) project, AH/E511139/1.