Almost three years ago, Steve Ramirez (neuroscience grad student at MIT) and I exchanged a few videos and blog posts about the scientific study of consciousness (see HERE for a run down). Ramirez began and ended our brief electronic debate convinced that I, like most other philosophers he’s encountered, have developed a profound misunderstanding of how science works. In his original post back in 2010, he argued that the tools of neuroscience have become precise enough to explain consciousness without remainder by causally reducing it to intracranial neural states. Two years later, Ramirez published a fine bit of neuroscience in the journal Nature, seemingly making good on his promise. He and his colleagues’ memory re-activation experiment on lab mice has been making its way around the Internet recently and also led to this TEDx talk. It is truly an ingenious experiment that raises all kinds of interesting scientific and ethical questions regarding how such “optogenetic reactivation” technology might be used in the future on human brains (see for example this Scientific American article about the arrival of “memory engineering”).
In their paper, Ramirez et al. don’t comment on the far more difficult because more general project of explaining consciousness itself, but rather focus in on memory, one particular faculty said to be related to consciousness. They claim in their paper to have proven that activation of “specific ensembles of hippocampal neurons that contribute to a memory engram is sufficient for the recall of that memory.”
Given that we know specific memories are often stored holographically (as Karl Lashley famously showed), I can’t find a reason to assume that activation of a specific neural ensemble is even necessary for the recall of a related memory, much less that such activation is sufficient for recall. It doesn’t make sense to me to claim that a memory is simply located in this or that group of neurons when so much research has already corroborated the global distribution of memories throughout the nervous system. That the controlled activation of these neural ensembles in surgically altered lab mice with giant lasers attached to their hippocampuses should seem to cause a reactivation of previously learned behaviors in no way proves or even suggests that the mouse’s experience of said memory is somehow caused by or localized within those particular cells.
Part of it depends what we mean by “recall.” If we define recall behavioristically, as was the case in this study, then sure, I will grant Ramirez et al.’s claim. When they flip the light switch, the mouse freezes (ostensibly because its fear response is being reactivated).
If, however, we approach memory from a phenomenological as well as a neurological point of view (i.e., neurophenomenology), we will not be able to settle for a behaviorist definition of memory recall. A neurophenomenologist would be left wondering what the mouse was experiencing when the light switch was flicked on. Was its recalled memory identical to the original experience? Was it the same in some ways, but different in others? How can we say? Claiming that reactivation of a localized group of neurons is sufficient to recreate the memory said to be somehow caused by or “inscribed” on those neurons begins to seem way more speculative from the neurophenomenological perspective. We simply don’t know what the mouse’s remembered experience is like, and unfortunately we can’t ask it. Whether or not we can or should perform similar experiments on speaking animals capable of describing their experience remains to be seen. I suspect it won’t be too much longer before technology is available that is just as precise but way less invasive than that used in Ramirez’s experiment. Indeed, developing this sort of technology is one of the main goals of Obama’s government funded Brain Initiative.
But I didn’t begin this post to pick at Ramirez et al.’s experiment. It is good science, as they say. I think they’ve developed an amazing research technique that will prove to have many applications in the future (medical, commercial, political, military, etc., applications). (I can only hope these future technological applications enhance rather than undermine the spiritual freedom, aesthetic intensity, and moral depth of human existence. Based on prior technological augmentations of human cognition, I can’t say I’m all that optimistic. I am open to being surprised. Life always finds a way.)
I am writing this post not to critique his science, but to redirect his wayward philosophical interpretations of that science. In a recent post on his blog titled “Conquering All Mysteries,” Ramirez writes:
The starry heavens above and the moral law within — these were the two things that Immanuel Kant claimed were immune to scientific investigation. Equally untouchable was the vague abstraction known as consciousness. That was in the 1700s… [Nowadays] consciousness can be explained solely in terms of orderly neural activity and is fully measurable; and, morality is and ought to be understood in light of the brain states of conscious creatures. We can — and do – have a neuroscience of both, because we’re not in the 1700s anymore.
My almost instinctual response to any scientist’s aggressive attempt to explain away consciousness by causally reducing it to neurophysiological mechanisms in the skull is to fall back upon transcendental philosophy. Transcendental philosophy is said to have begun with Kant’s critiques (of pure reason, practical reason, and judgment), all published in the last decades of the 18th century. Kant’s philosophical discovery (or invention?) of the transcendental method has made him the modern equivalent of Aristotle (who for 1500 years Islamic and Western scholars simply referred to as “the Philosopher”). But unlike with Aristotle, whose metaphysical decrees were swallowed almost without chewing by medieval European thinkers, Kant’s work repeatedly mutated as it was chewed over, swallowed, digested, and improved upon by the best scientific minds of his era. Fichte, Schelling, and Hegel (and Husserl in the 20th ce.) vastly expanded the reach of transcendental philosophy. Where Kant believed he had been forced “to limit knowledge in order to make room for faith,” his three main German predecessors, each in their own way, broke open all dogmatic limits to scientific knowledge–not only to knowledge of nature, but also to knowledge of God (because as Spinoza taught us, God is Nature).
Kant didn’t exactly claim that the natural world and human consciousness were “immune to scientific investigation.” Rather, he tried to uncover the a priori conceptual and perceptual conditions under which any science of nature–whether cosmic or human nature–must necessary proceed in order to remain scientific. Kant was in a sense trying to place limits on positive science (whether it purported to produce knowledge of the cosmos, the soul, or the divine), but he was also trying to provide a firm foundation for the possibility of scientific investigation of the natural world (the world that appears to our senses and conforms to our logic). I don’t count myself as a transcendental philosopher when in conversation with other philosophers (see HERE for example), but when confronted by anti-philosophical scientific materialists, I can’t help but invoke the transcendental position. If subjective consciousness is the condition for the possibility of the experience and cognition of external objects (as transcendentalists argue), then an explanation in terms of those objects, no matter how sophisticated or complexly arrayed they may be, will always fail to explain said consciousness. What so many scientific materialists seem to neglect is that a reduction of human consciousness to the deterministic playing out of neurophysiological mechanisms is also a reduction of the scientific enterprise to a talking primate’s delusion of grandeur. If consciousness (and with it, rigorous logic and honest empiricism) is just an empty word, just a culturally acquired illusion with no causal or physical role to play, then we have no reason to take science–one of human consciousness’ greatest achievements (right up there with art, religion, and morality)–seriously. Neuroscientific reductionism (usually unknowingly) undermines its own philosophical conditions of possibility. As Hegel argued, it treats spirit as though it were a bone.
Ramirez’s approach to the brain remains at the level of what Owen Barfield called “dashboard knowledge.” Such knowledge gives us the ability to manipulate and control the brain from the outside, but tells us very little about how the brain is related to the consciousness we experience directly “in here.” For the latter, we need something like phenomenology or contemplative practice (or both, as Evan Thompson argues). Any hope we have of explaining experience (whatever that might mean…) is going to have to emerge as much from a transformation within experience (i.e., through a new first person expression of subjectivity) as from outside it by way of a new third person description of or technological intervention upon the behavior of the objective brain and body.
Ramirez claims that his hypothesis regarding the neural causes of consciousness is falsifiable. I fail to see how this is the case. He isn’t researching the brain to see if it causes consciousness. That the brain causes consciousness is a presupposition of his neuroscientific research method. If we grant that there is some kind of correlation between conscious experience and neural processes (which I am perfectly willing to do), he can’t help but confirm his hypothesis with every experiment. Ramirez’s hypothesis is blind to the difference between mind-brain correlation and brain-mind causation (as I argued in my response to him three years ago). It is no surprise that neuroscientists operating from within such a reductionistic paradigm can only confirm their own initial hypothesis. Brain-mind reductionism is more a metaphysical position than a falsifiable scientific hypothesis. Its faults and merits would be better considered in the court of philosophy. The situation today is no different than it was for Kant more than 200 years ago. There were reductionistic neurophysiologists then, too. His transcendental arguments still apply, for those who care to understand them.
Ramirez responds to the claim of a philosopher in this MIT neuroscience magazine (see p. 23) that scientific study of the brain has only shown and could only ever show mind-brain correlation rather than brain-mind causation. According to Ramirez, we philosophers “deeply misunderstand what correlation and causation really mean.” But his rebuttal entirely misses the point both the author of the magazine piece and myself are trying to make, which is not at all concerned with whether physical manipulations of the brain (using laser beams or pharmaceuticals, etc.) can alter consciousness. Obviously they can. The point is that, no matter how proficient we are at altering consciousness by manipulating the brain (i.e., “dashboard knowledge”), this tells us nothing about the causal relationship between physical brain states and subjective experience, nor does it tell us anything about the ontology of the latter. We know they must be somehow related, yes. But how? If Ramirez or any other neuroscientific reductionist has a theory for how the grey matter in the skull could generate mental experience, I’m all ears. Thus far, I’ve yet to hear of such a theory. What I hear are aggressively asserted unfalsifiable metaphysical claims masquerading as science, claims that can only be properly adjudicated philosophically.
In philosophy, there are no final solutions. No philosopher’s judgment ever goes unchallenged by another’s. Every genuine philosophical problem is therefore an infinite task. I approach the hard problem of consciousness as precisely such an infinite task. If there is an explanation for experience, it better include an injunction for erasing experience, a sort of Zen koan or psychedelic trip that opens me to the emptiness that is supposed to reside inside my “no-mind.”
Here is my original video response to Steve Ramirez three years ago:
Here are some of my reflections from several years ago on materialism: