From the first sentence, the article by Morsella et al. assumes that consciousness has a function. The authors never consider the possibility that it may not and make many further assumptions that have frequently been challenged in the literature.
The question of function relates closely to what is probably the greatest gulf between theorists – whether consciousness is or is not something extra, or additional to, neural and biological processes. If it is, the hard problem (how subjective experiences arise from objective brain events; Chalmers Reference Chalmers1995) is real, and consciousness must have evolved for a reason. If it is not, as in the case of the many variants of reductive or eliminative materialism, identity theory, and physicalism, then there is no hard problem, and consciousness evolved because perception, memory, learning, and other useful abilities evolved. Responding to the many well-known thought experiments, only those who think consciousness is something extra believe that philosophical zombies are possible and that Mary the colour scientist learns something new when she emerges from her black-and-white room (Jackson Reference Jackson1982).
The authors are clearly in the first camp, not only with their concept of the “conscious field” and its contents, but also in their use of such phrases as “consciousness itself” (sect. 4.3, para. 2), the “regions responsible for consciousness” (sect. 3.4, para. 2), and brain regions or processes “associated with consciousness” (e.g., sect. 1.4, para. 2, and elsewhere in the target article). They reject Cartesian dualism (explicitly claiming to avoid the homunculus fallacy) but admit to retaining aspects of the Cartesian theatre. So their theory is a version of Cartesian materialism (Dennett Reference Dennett1991), as revealed in such phrases as “contents enter consciousness” (sect. 4.1, para. 2) and percepts and representations “become conscious” (sect. 3.5, para. 7).
These phrases imply that some processes, percepts, or representations are conscious while others are not, and the authors claim, as though it were uncontroversial, that there is a subset consensus on this issue. Citing Bleuler's (Reference Bleuler and Brill1924) textbook, they say, “When adopting a descriptive standpoint, even the most cursory examination of the brain reveals a contrast between conscious and unconscious processes” (sect. 1.2, para. 2). No, it does not. Examination with the naked eye reveals white and grey matter; with a microscope, glial cells, neurons, axons, and synapses; and with modern scanning techniques, further detail. Nowhere can we see what I have called the “magic difference” between conscious and unconscious regions or processes (Blackmore Reference Blackmore2011). They claim that “the contrast between conscious and unconscious processes in the brain is somewhat inevitable” (sect. 1.2, para. 2). No. Not only is it not “inevitable,” but also it is deeply problematic. What could it mean? That some brain processes have subjective experiences attached to them; that some give rise to consciousness; that the hard problem applies to only a subset? Indeed, saying that a brain process is “conscious” entails the mereological fallacy – that is, ascribing to part of an animal “an attribute which it makes sense to ascribe only to the animal as a whole” (Bennett & Hacker Reference Bennett and Hacker2003, p. 240). Morsella et al. are not alone in taking this view, and the hunt for the neural correlates of consciousness is based on the premise that such a distinction will be found, but so far there is no agreement about whether it has been or will be found.
The same can be said of the integration consensus. Claiming that the function of consciousness is integration, Morsella et al. contend that “consciousness serves an essential, integrative role for the somatic nervous system” (sect. 6, para. 5) and “consciousness integrates neural activities and information-processing structures that would otherwise be independent” (sect. 2.2, para. 1). I want to ask not only how subjective experience can be said to integrate objective activities and structures (implying a version of the hard problem or possibly some kind of unexplained downward causation), but also, more fundamentally, why these activities and structures need something extra to integrate them. Are they not integrated by structural connections or by the various processes proposed to account for binding (Cleeremans Reference Cleeremans2003)? Contrary to the authors' claim, there is no consensus over integration either.
The confusion is clearest in their discussion of global workspace theory (GWT). Morsella et al. cite more than 20 papers and books as evidence for this consensus but include in this list authors who hold totally opposed interpretations of GWT. These too can be divided into two main camps. On the one hand, there is a loosely Cartesian materialist or implicitly dualist account like the one proposed here. According to this, and the original formulation by Baars (Reference Baars1988), items of information (or processes, percepts, thoughts, etc.) compete for access to the global workspace where they “become conscious” and are broadcast to the rest of the unconscious audience. This interpretation retains the hard problem and all of the difficulties of Cartesian materialism.
A completely different interpretation is more common (though not universal) in neuronal global workspace theory (Dehaene & Naccache Reference Dehaene and Naccache2001) and means that no process or information has to “become conscious” or “enter consciousness.” As Dehaene (Reference Dehaene, Bayne, Cleeremans and Wilken2009) explains, brain-scale broadcasting creates the possibility of verbal and other types of report, and this is experienced as a conscious state. There is no additional consciousness or subjectivity. This is what Dennett (Reference Dennett2005), more colourfully, calls “fame in the brain” or “cerebral celebrity.” Fame is not something additional to being widely known, nor is consciousness something additional to being widely broadcast. In this interpretation of GWT, there is no dualism or hard problem. These views are deeply opposed, and there is no consensus as to which is right.
In summary, the article by Morsella et al. proposes an implicitly dualist or Cartesian materialist theory of consciousness without citing the many well-known problems with such theories and claiming consensus where none exists. Their discussion of olfaction is a helpful and interesting addition to our understanding, but their theory of the function of consciousness does not stand up to scrutiny.
From the first sentence, the article by Morsella et al. assumes that consciousness has a function. The authors never consider the possibility that it may not and make many further assumptions that have frequently been challenged in the literature.
The question of function relates closely to what is probably the greatest gulf between theorists – whether consciousness is or is not something extra, or additional to, neural and biological processes. If it is, the hard problem (how subjective experiences arise from objective brain events; Chalmers Reference Chalmers1995) is real, and consciousness must have evolved for a reason. If it is not, as in the case of the many variants of reductive or eliminative materialism, identity theory, and physicalism, then there is no hard problem, and consciousness evolved because perception, memory, learning, and other useful abilities evolved. Responding to the many well-known thought experiments, only those who think consciousness is something extra believe that philosophical zombies are possible and that Mary the colour scientist learns something new when she emerges from her black-and-white room (Jackson Reference Jackson1982).
The authors are clearly in the first camp, not only with their concept of the “conscious field” and its contents, but also in their use of such phrases as “consciousness itself” (sect. 4.3, para. 2), the “regions responsible for consciousness” (sect. 3.4, para. 2), and brain regions or processes “associated with consciousness” (e.g., sect. 1.4, para. 2, and elsewhere in the target article). They reject Cartesian dualism (explicitly claiming to avoid the homunculus fallacy) but admit to retaining aspects of the Cartesian theatre. So their theory is a version of Cartesian materialism (Dennett Reference Dennett1991), as revealed in such phrases as “contents enter consciousness” (sect. 4.1, para. 2) and percepts and representations “become conscious” (sect. 3.5, para. 7).
These phrases imply that some processes, percepts, or representations are conscious while others are not, and the authors claim, as though it were uncontroversial, that there is a subset consensus on this issue. Citing Bleuler's (Reference Bleuler and Brill1924) textbook, they say, “When adopting a descriptive standpoint, even the most cursory examination of the brain reveals a contrast between conscious and unconscious processes” (sect. 1.2, para. 2). No, it does not. Examination with the naked eye reveals white and grey matter; with a microscope, glial cells, neurons, axons, and synapses; and with modern scanning techniques, further detail. Nowhere can we see what I have called the “magic difference” between conscious and unconscious regions or processes (Blackmore Reference Blackmore2011). They claim that “the contrast between conscious and unconscious processes in the brain is somewhat inevitable” (sect. 1.2, para. 2). No. Not only is it not “inevitable,” but also it is deeply problematic. What could it mean? That some brain processes have subjective experiences attached to them; that some give rise to consciousness; that the hard problem applies to only a subset? Indeed, saying that a brain process is “conscious” entails the mereological fallacy – that is, ascribing to part of an animal “an attribute which it makes sense to ascribe only to the animal as a whole” (Bennett & Hacker Reference Bennett and Hacker2003, p. 240). Morsella et al. are not alone in taking this view, and the hunt for the neural correlates of consciousness is based on the premise that such a distinction will be found, but so far there is no agreement about whether it has been or will be found.
The same can be said of the integration consensus. Claiming that the function of consciousness is integration, Morsella et al. contend that “consciousness serves an essential, integrative role for the somatic nervous system” (sect. 6, para. 5) and “consciousness integrates neural activities and information-processing structures that would otherwise be independent” (sect. 2.2, para. 1). I want to ask not only how subjective experience can be said to integrate objective activities and structures (implying a version of the hard problem or possibly some kind of unexplained downward causation), but also, more fundamentally, why these activities and structures need something extra to integrate them. Are they not integrated by structural connections or by the various processes proposed to account for binding (Cleeremans Reference Cleeremans2003)? Contrary to the authors' claim, there is no consensus over integration either.
The confusion is clearest in their discussion of global workspace theory (GWT). Morsella et al. cite more than 20 papers and books as evidence for this consensus but include in this list authors who hold totally opposed interpretations of GWT. These too can be divided into two main camps. On the one hand, there is a loosely Cartesian materialist or implicitly dualist account like the one proposed here. According to this, and the original formulation by Baars (Reference Baars1988), items of information (or processes, percepts, thoughts, etc.) compete for access to the global workspace where they “become conscious” and are broadcast to the rest of the unconscious audience. This interpretation retains the hard problem and all of the difficulties of Cartesian materialism.
A completely different interpretation is more common (though not universal) in neuronal global workspace theory (Dehaene & Naccache Reference Dehaene and Naccache2001) and means that no process or information has to “become conscious” or “enter consciousness.” As Dehaene (Reference Dehaene, Bayne, Cleeremans and Wilken2009) explains, brain-scale broadcasting creates the possibility of verbal and other types of report, and this is experienced as a conscious state. There is no additional consciousness or subjectivity. This is what Dennett (Reference Dennett2005), more colourfully, calls “fame in the brain” or “cerebral celebrity.” Fame is not something additional to being widely known, nor is consciousness something additional to being widely broadcast. In this interpretation of GWT, there is no dualism or hard problem. These views are deeply opposed, and there is no consensus as to which is right.
In summary, the article by Morsella et al. proposes an implicitly dualist or Cartesian materialist theory of consciousness without citing the many well-known problems with such theories and claiming consensus where none exists. Their discussion of olfaction is a helpful and interesting addition to our understanding, but their theory of the function of consciousness does not stand up to scrutiny.