You might say that, by reactivating a certain pattern of brain activity, the scientists artificially created recall. This is true, but it doesn’t address the important question of what memory is or where it’s stored. You see, experiences correlate with brain activation patterns; we know that. So, if you induce a certain brain activation pattern in mice and associate that with a shock, it’s no surprise that the shock will be cognitively linked to any future experience that triggers the same brain activation pattern. But that’s not the question. The question is, when I close my eyes and remember my dead father, how do I know what exact pattern of brain activity to bring back to my brain? Where is the information stored that allows me to reconstruct that pattern?
In the MIT experiment, the scientists created their own storage mechanism: they genetically modified the mice to grow light-sensitive switches in each neuron that got activated in environment A. Only the activated neurons grew the light-sensitive switches, so the distribution of the switches recorded the neural correlates of the original experience of the mice in their original environment. The scientists could then turn these same neurons back on later, by shinning light on the mice’s brains, thereby recreating their original experience in a totally different environment. Of course, this doesn’t explain how mice remember things when they haven’t been engineered to grow light-sensitive switches in their neurons! The experiment explains exactly nothing about the mechanism of memory storage simply because it bypasses it altogether! It was the scientists who recorded and stored the information, and then used this information to create a pattern of brain activity; not the mice. How do the mice do it when there are no scientists to record, store and re-launch the information in their brains?
The experiment also says nothing new about the nature of experience. That experience is correlated with certain patterns of brain activity is very old news. That they could create an association between two events by activating their respective patterns together in the brain is also no news, since this has been shown by classical conditioning since the time of Pavlov. The only novelty – and, make no mistake, it’s amazing and important, just not in the way the article portrays it – is the scientists’ ability to record and then re-activate a particular pattern of brain activity. This may have important future applications in, for instance, new treatments of brain illness and perhaps even in education. But don’t expect a ‘Recall’ shop near you any time soon. Don’t expect a solution to the ‘hard problem of consciousness.’ And don’t expect an answer to the nature and location of episodic memory.
To me, the key insight here is how, through lack of rigor and misplaced enthusiasm, an entirely undemonstrated notion can be hyped by the mainstream media to the point of looking fully established. How many well-meaning people out there, who briefly read this article, weren’t thinking: ‘Wow, it’s a done deal…memory and consciousness really are in the brain’? Could we even blame them? I suspect that many journalists feel safe to exaggerate if they’re backed by the clout of the mainstream metaphysics; what could go wrong, right?
While reading this essay, you’re thinking more critically about this specific study. But how many similar articles about other studies have you casually read over the years? How many of your implicit beliefs and convictions today –‘facts’ you take for granted – have been subtly created through exposure to similarly misleading hype? Scary, isn’t it?
3.5. Psychedelics and the mind-body problem
Early in 2012, a study was published on the effects of psilocybin – the active ingredient of magic mushrooms – on brain function.88 It received enormous media attention over the subsequent months. Indeed, the study attracted my own interest because the researchers observed only reductions in brain activity while subjects were having mind-boggling psychedelic experiences. This is, of course, counterintuitive from a materialist perspective: how can an extreme increase in the breadth and intensity of experience occur without an accompanying increase in brain activity? Even worse: how can it happen with a decrease in brain activity?
Preliminary reports on this psychedelic study had already indicated that the researchers had observed reductions of activity,89 but the explanation could have been that the drug selectively affected inhibitory brain processes, thereby allowing excitatory processes to grow unchecked elsewhere. Let me unpack this a bit for you: under materialism, inhibitory brain processes are like bouncers guarding the entrance of the club of consciousness. Excitatory brain processes become conscious if they get into the club, but the bouncers prevent many from entering, so we never become aware of them. If the drug took out the bouncers, the idea is that many excitatory processes that would otherwise remain unconscious could then flood into the club. This would explain the ‘trip.’
The problem is that the researchers observed no brain activation anywhere in the brain. Quoting the study: ‘We observed no increases in cerebral blood flow in any region.’90 You see, if the club of consciousness got flooded because the bouncers were taken out, the researchers should still have seen, somewhere in the brain, the increases in activity corresponding to the excitatory processes now invading it. But they didn’t. In fact, they observed that the more the drug de-activated the brain, the more intense were the subjective experiences reported by the subjects.91 This is highly counterintuitive under materialism. Subjects reported experiences like ‘geometric patterns,’ ‘extremely vivid imagination,’ seeing their ‘surroundings change in unusual ways,’ as well as experiences with a ‘dream-like quality.’92 Without brain activations observed anywhere, and with the subjects stuck inside a brain scanner, this is difficult for a materialist to make sense of. One would expect, for instance, visions of geometric patterns to be caused by activations of visual areas of the brain. But the researchers not only did not observe these activations, they reported that ‘there were …additional …signal decreases …in higher-order visual areas.’93
If you want to have an idea of the kind of structured, coherent, evocative and unfathomably intense subjective experiences that people have under the effect of psilocybin, I recommend the Erowid online experiences vault.94 If you browse through the reports in there, you will likely convince yourself that, if consciousness is indeed merely the result of brain metabolism, it is inconceivable that such experiences could occur without measurable increase in this metabolism. Yet, the opposite happens.
Surprisingly, the researchers went as far as acknowledging that their results suggested that the brain was at least partly akin to a consciousness localization phenomenon (as I argue in essay 2.1). They wrote that their findings were ‘consistent with Aldous Huxley’s ‘reducing valve’ metaphor …which propose[s] that the mind/brain works to constrain its experience of the world.’ To help you know precisely what Huxley’s hypothesis was, here is the appropriate quote from his book The Doors of Perception and Heaven and Hell:
The suggestion is that the function of the brain and nervous system and sense organs is in the main eliminative and not productive. Each person is at each moment capable of … perceiving everything that is happening everywhere in the universe. The function of the brain and nervous system is to protect us from being overwhelmed …by shutting out most of what we should otherwise perceive or remember at any moment, and leaving only that very small and special selection which is likely to be practically useful.95
Also interesting is the researchers’ observation that the highest de-activations of the brain occurred in areas associated with the ego.96 This is consistent with the age-old idea that the ego prevents us from perceiving the unity and transcendence of consciousness. As discussed in essay 2.1, I liken the brain to a whirlpool in a transpersonal stream of experiences. So when I read this part of the study, I couldn’t help but visualize the deactivation of the ego as analogous to a disruption of the whirlpool, which allows consciousness to partly and temporarily de-localize beyond the space-time locus of the body. When some specific brain functionality is taken out, consciousness declenches and expands.
Eminent neuroscientist Dr. Christof Koch and I once had an indirect debate on this study via interviews we both gave to the same Internet show.97 Koch claimed that my position – as discussed above – was too simplistic, given that consciousness isn’t directly proportional to global brain activity due to the role of inhibitory processes. I already discussed above – and, much more rigorously, in my earlier book Why Materialism Is Baloney98 – why references to inhibitory processes do not solve the problem. Whichever way one presents the issue, under materialism a fully inactive brain cannot be conscious because consciousness allegedly is some kind of activity somewhere in the brain. Therefore, despite the role of inhibitory processes, a significant increase in the breadth and intensity of experience must correlate with a corresponding increase in activity somewhere in the brain.
This becomes clear when you consider this: lucid dreams and psychedelic experiences are similar in that neither can be attributed to sensory inputs. Yet, in a lucid dream, when we do something as dull as clenching our dreamed-up hands, scientists can discern the corresponding brain activations from the baseline of brain activity.99 But when we have unfathomable psychedelic excursions into ‘other universes,’ scientists see no brain activation whatsoever when contrasted to the baseline. If this isn’t an anomaly under materialism, then materialism makes no significant predictions as far as consciousness and might as well be declared operationally irrelevant.
Whatever the ultimate interpretation of these results will be, it is important that the results themselves be reported factually. But look at this quote from a CNN news piece reporting on the study in question:
[The researchers] scanned the brains of 30 healthy volunteers after they had been injected with psilocybin and found the more primitive regions of the brain associated with emotional thinking became more active and [a region] associated with high-level thinking, self-consciousness and introspection, was disjointed and less active.100
What can one say? According to the study report, there were no increases in activity anywhere. What increased was coupling in some regions, but that’s not activity. The news piece essentially conveys the opposite of what was found.
The same team of researchers continued their efforts to understand the effects of psilocybin in the brain and published another scientific article in 2014 elaborating on their new results.101 Once again, the media seems to have reported misleadingly on the findings. The news piece in question stated that the researchers had ‘found increased activity in regions of the brain that are known to be activated during dreaming.’102 If this were true, it would contradict the conclusions of the earlier 2012 study. But let’s look at what the researchers were investigating this time:
…the effects of psilocybin on the variance of brain activity parameters across time has been relatively understudied and this line of enquiry may be particularly informative …Thus, the main objective of this article is to examine how psilocybin modulates the dynamics and temporal variability of resting state [brain] activity.103
Clearly, unlike in the 2012 study, the researchers this time weren’t reporting on brain activity, but on the variability of that activity; that is, on how much and how fast it changed over time. Naturally, a brain displaying higher levels of activity variation can still have, overall, much lower levels of activity than normally. A jetliner in cruise flight has very high speed, but very low speed variability. You will experience more speed variability if you are riding a motorcycle downtown – constantly stopping in traffic lights, accelerating on long stretches of straight road, slowing down before turns, avoiding other traffic, etc. – but the speed of the motorcycle will still be much lower than that of the jetliner. Do you see the point?
The researchers went on to report on their findings:
In summary, increased variance in [brain activity] was observed …This change in variance is the expression of an increased amplitude of [brain activity] fluctuations …bursts of high amplitude activity have been seen in human rapid-eye movement (REM) sleep …Given that phenomenological similarities have previously been noted between the psychedelic …and dream states, it is intriguing to consider whether [this] may be an important common property of these states.104
What was found to increase was thus the variability of brain activity in dream-related regions, not activity itself. As such, the new study doesn’t contradict the earlier findings.
The confusion could, in principle, have arisen from simple misunderstanding. The language used in the 2014 scientific article, although strictly accurate, is indeed conducive to just this kind of misinterpretation. For instance, the article talks about the ‘total spectral power’ of brain activity in certain regions having ‘increased.’105 This seems to suggest that brain activity increased, doesn’t it? But it has nothing to do with it. The word ‘power’ is misleading here, for it’s used in a very specific technical sense: it corresponds to the square of each frequency component of the original brain activity signal, wherein phase information is discarded. Therefore, an increase in ‘total spectral power,’ in and of itself, neither implies nor suggests that brain activity increased.106
The use of language like ‘higher total spectral power’ and ‘increased amplitude variations’ seems to suggest that, unable to make sense of their own 2012 results, the researchers were looking for some quantifiable neural parameter that did increase during psychedelic trances. It is as if they were pressed to find that something – anything –increased. After all, the materialist intuition screams that, if consciousness expands, something in the brain must increase. Since materialism today offers no coherent explanation for how consciousness allegedly arises from matter (see essay 3.1), it is conceivable, in principle, that experience could arise from variations of neural activity level, as opposed to activity itself. Nonetheless, this would contradict a whole host of other correlations routinely observed between experience and the sheer level of brain activity, such as the lucid-dreaming study referred to earlier.107 Materialism cannot have it both ways.
I initially attributed the confusion to science journalism lacking rigor and in-depth grasp of the research. But then I found a popular science piece written not by a journalist, but by one of the researchers himself: Dr. Carhart-Harris. Titled ‘Magic mushrooms expand your mind and amplify your brain’s dreaming areas,’ Carhart-Harris goes on to say that psilocybin ‘increased the amplitude …of activity’ in brain regions associated with dreaming.108 This is not corroborated by the 2014 technical paper, which reports an increase only in the amplitude of variations of brain activity levels. Carhart-Harris then speculates that psychedelics enabled ‘disinhibited activity’ in neural systems associated with emotions.109 This again suggests that activity increases somewhere in the brain as a result of psychedelic use, both in contradiction to Carhart-Harris’ own 2012 results and without substantiation in the 2014 technical article. In another popular article in which Carhart-Harris is quoted, he goes beyond mere suggestion: ‘You’re seeing these areas getting louder, and more active,’ he is quoted as saying. ‘It’s like someone’s turned up the volume there.’110 What’s going on here?
Puzzled, I emailed Carhart-Harris asking for clarifications.111 He and Enzo Tagliazucchi, the main author of the second study, replied promptly and very generously. The email exchange that ensued over several days confirms my assessments above. Namely:
• Indeed, they found just an increase in the variability of the brain activity signal, that is, an increase in fluctuations as opposed to a constant, unchanging signal.112 Phase information is lost in the variability analysis, so no conclusions can be extracted about the average amplitude of the signal.
• Tagliazucchi interprets the variability of brain activity during rest as analogous to actual brain activity when the subject is engaged in performing a task. The variability may show how often spontaneously occurring neural processes engage and disengage, thus providing a measure of ‘something going on’ in the brain while the subject is at rest.113 As such, variabi
lity could be looked upon as a kind of ‘meta-activity’ measurement that may correlate better with the qualitative changes in subjective experience reported by the subjects.
• Actual brain activity has not been found to increase anywhere in the brain.
After having seen an earlier draft of this essay, the researchers requested that I do not quote their email messages to me; a request I find disappointing but which I am honoring. All I can thus say is that, following extensive and in-depth exchanges with them,114 it is my genuine understanding that Carhart-Harris’ popular science piece and some of his statements quoted in the press were inaccurate. Carhart-Harris himself has neither explicitly agreed with nor denied this assessment, although I believe it to be an inescapable implication of the email communications.
I see nothing wrong with exploring the idea of ‘meta-activity.’ In fact, I applaud it. I just feel that the terminology should be used rigorously and unambiguously to avoid misleading readers and the media alike. You see, brain activity – that is, metabolism – is one thing; variations of brain activity are another thing entirely. Speed is not the same as acceleration. A car that repeatedly stops, accelerates and then stops again is not necessarily a car that travels fast. The theoretical hypothesis that ‘meta-activity’ may be a more useful measurement does not make it valid to use the word ‘activity’ as shorthand for ‘activity variability.’
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