No, Split-Brain Patients Do Not Have "Two Conscious Minds in One Skull"

Once again, we have an article in which a neuroscientist misinforms us very badly on the very important topic of split-brain patients. This time it is an article I read recently at the MIT Press Reader. The article is entitled "What Split-Brain Patients Reveal About Consciousness." After discussing facts that contradict his claim, the author (neuroscientist Christof Koch) senselessly refers without any warrant to "two conscious minds in one brain." 

A split-brain patient is typically a patient who underwent an operation severing the corpus callosum, a mass of fiber-like nerves that connect the left hemisphere of the brain and the right hemisphere of the brain . Each of these hemispheres makes up half of the brain. Such an operation is typically done to treat very severe and frequent seizures. Below is a Google Gemini infographic on the topic of this operation, called a corpus callosotomy. 

After this operation is performed, a person is left with two disconnected brain halves. If it were true that your brain makes your mind, such an operation should produce two minds in the same individual. But no such thing happens. 

In 2014 the wikipedia.org article on split-brain patients stated the following:

"In general, split-brained patients behave in a coordinated, purposeful and consistent manner, despite the independent, parallel, usually different and occasionally conflicting processing of the same information from the environment by the two disconnected hemispheres...Often, split-brained patients are indistinguishable from normal adults."

Neuroscientist Koch tells us something similar in the middle of his article. He states this:

"Remarkably, once these 'split-brain' patients recover from the surgery, they are inconspicuous in everyday life. They see, hear, and smell as before; they move about, talk, and interact appropriately with others, and their IQ remains unchanged. They have their usual sense of self and report no obvious alteration in their perception of the world — no shrinkage of their visual field, for example. The surgeons who pioneered this operation, including Joseph Bogen at Loma Linda University in Southern California, were puzzled by this lack of clear symptoms." 

Koch then goes into an account claiming that certain things were observed in split-brain patients. It is the kind of account that typically goes on when authors will be making false "two minds in one skull" claims: an account that has no link to particular papers. What we have is flimsy anecdotal evidence making claims about what supposedly happened in a handful of patients. We don't have straightforward accounts of what was observed, but accounts that are littered with dubious or unbelievable interpretations. And we don't have specific mentions of what exactly one particular identified person did. Koch states this:

"If specific data are given to one hemisphere, that information is not shared with its twin on the other side. Furthermore, only one hemisphere, typically the left one, speaks. That is, if the right hemisphere is lost or silenced by anesthesia, the patient can still talk, which is why the left hemisphere is called the dominant hemisphere. The right hemisphere by itself has only limited language comprehension and is mute, though it can grunt and sing. So, when engaged in conversation with a split-brain patient, it is the person’s left hemisphere that is doing all the talking."

Data is given to persons, not to single hemispheres in the brain. And there is never any evidence that learned information is stored in a brain.  The microscopic examination of brain tissue has never revealed the slightest trace of anything anyone learned,  nor have any brain scans. It is not a hemisphere of the brain that speaks or comprehends or sings, but a person who speaks and comprehends and sings. So Koch is writing erroneously when he states "only one hemisphere, typically the left one, speaks"; and he is speaking just as erroneously when he says that the right hemisphere sings; and he is speaking just as erroneously when he claims that the right hemisphere comprehends something.   Both hemispheres of the brain are equally active in normal people and split-brain patients, so it is ridiculous to say of anyone "only one hemisphere, typically the left one, speaks." Brain hemispheres don't speak or sing or comprehend; people speak and sing and comprehend. 

In the paragraph quoted above and his next paragraph, Koch fails to link to any scientific papers, and fails to mention any specific persons who were observed.  He mentions some alleged perceptual difficulties in split-brain patients. Using the phrase "the patient" in an ambiguous way, he claims that "The patient can’t name an object presented in the left visual field because that image is processed by his mute right visual cortex." We can't tell whether he is referring to only one patient or to split-patients in general. Koch also makes this claim:

"If a key is placed in the patient’s right hand, with the hand under the table and out of sight, they will quickly name it. Touch information from their right hand is transmitted to their left hemisphere, where the object is identified, and its label is relayed to the language center. If the key is placed in the person’s left hand, however, the patient is unable to identify it and rambles on."

But what confidence can we have in such claims, as Koch does not mention any source for such generalizations? If there were actually good evidence for such claims, why would Koch have failed to link to the relevant paper reporting this claim? And if a single paper reported seeing such a thing in one person, why should we assume that such a thing is generally true of split-brain patients, without substantial replication of such a result?

We then have this extremely weak piece of evidence, which consists of an anecdote involving one person, and a dubious self-report provided by that person:

"Victor Mark, a neurologist at the University of North Dakota, videotaped an interview with a split-brain patient. When asked how many seizures she had following her operation, her right hand held up two fingers. Her left hand then reached over and forced the fingers on her right hand down. After trying several times to tally her seizures, she paused, then simultaneously raised three fingers with her right hand and one with her left. When Mark pointed out this discrepancy, the patient commented that her left hand frequently did things on its own. A fight ensued between the two, looking like slapstick comedy. Only when the patient grew so frustrated that she burst into tears was I reminded of her sad situation."

As evidence of anything, this is extremely weak. We have no link to the original account. We do not have a link to this video, or a transcript of what the patient said.  Someone (maybe Victor Mark) has claimed that the "patient commented that her left hand frequently did things on its own." But we don't know exactly what the exact words of the patient were, and we don't know whether that was a response to some "leading question" suggesting such a thing. What we have is a second-hand account of someone claiming that a brain-damaged person said a particular thing. That is extremely flimsy as evidence. We don't know what exactly the patient might have meant by saying such a thing; and we can't be sure that any such thing was said as Koch suggests.

Koch then states this, making an outrageous misstatement that has no warrant in  the few anecdotes he has presented:

"Studies with split-brain patients, work for which Sperry was awarded the Nobel Prize in 1981, teach us that cutting the corpus callosum cleaves the cortico-thalamic complex in two but leaves consciousness intact. Both hemispheres are independently capable of conscious experience, one being much more verbal than the other. Whatever the neural correlates of consciousness are, they must exist independently in both hemispheres of the cerebral cortex. Two conscious minds in one skull. "

Two conscious minds in one skull? Nothing that Koch has discussed provides any warrant for such a claim. To the contrary, Koch's previous statement contradicts such a claim.  As I previously mentioned, Koch stated this:

"Remarkably, once these 'split-brain' patients recover from the surgery, they are inconspicuous in everyday life. They see, hear, and smell as before; they move about, talk, and interact appropriately with others, and their IQ remains unchanged. They have their usual sense of self and report no obvious alteration in their perception of the world — no shrinkage of their visual field, for example."

Split-brain patients do not have two conscious minds, but a single unified conscious mind.  The result of split-brain operations dividing a brain into two separated halves is a result the opposite of what we would expect under claims that brains make minds. 

It is almost always the same when neuroscientists or layman  materialists tell this  outrageous falsehood that split-brain patients have two minds. Almost always, they do not link to any relevant papers. Almost always, all that is offered is a few crummy anecdotes, which usually take the form of second-hand evidence or third-hand evidence.  Basically what is going on is a tactic of "give them an inch, and hope they take a mile." Don't fall for such silliness, which is not following decent standards for evidence. 

In Chapter 7 of the book you can read here, we have on page 111 a paper from 1944:

We have a report on two split-brain patients who had their  corpus callosum severed, leaving them with two separated brain hemispheres. The first one (called Case 1) was a married farmer. On page 113 we read that his "corpus callosum was sectioned completely" to treat seizures. This means the fibers connecting his two brain hemispheres were completely severed.  

Here is the page discussing the patient's split-brain operation severing his corpus callosum,  and the patient's status after the operation:

We have no report of anything very unusual. There is nothing to justify any claim of "two conscious minds in one skull." Contrary to Koch's claim about dysfunction in the left hand of people with split brain operations removing the corpus callosum connecting the two brain hemispheres, we are told on the page shown above that this Case 1 split-brain patient with a severed corpus callosum "was able to write with either hand with eyes open or when blindfolded." 

Page 115 suggests that a later examination indicated there were no big problems detected with this split-brain patient:

There is nothing in the account of this paper to give any support for the claim that split-brain patients have "two conscious minds in one skull." We are told that the patient could correctly interpret skin writing, and the wording suggested this skill persisted in both hands. 

The scientific paper "Functional outcomes in adults following corpus callosotomy: A systematic review" (which you can read here) summarizes case studies of split-brain patients who had their corpus callosum severed.  We have a systematic methodology that approaches this topic in a scientific way, unlike Koch's palm-full-of-wobbly-anecdotes affair. The paper summarized 15 different studies reviewing 73 different subjects having the split-brain operation.  18 of these subjects are identified as "Total CC," by which the paper means a total corpus callosotomy completely severing the corpus callosum, leaving two disconnected brain hemispheres.  

We read at the beginning of the paper that "Intellectual quotient is largely preserved post corpus callosotomy of different extents." We later read this: "Three individuals that underwent a total CC [corpus callosotomy] were reported to have maintained their pre-surgical level of intellectual functioning at the time of post-surgical follow-up [[18], [19], [20]], while one individual was reported to show a decline despite a reduction in seizure burden [21] (Table 2)." 

Under the "brains make minds" dogma, we should expect that this "total CC" (corpus callosotomy) involving a complete severing of the corpus callosum should have produced radical intellectual disability or total mental incapacity. But the paper says that "intellectual functioning (refer to Section 3.1), whether divided into verbal and performance based abilities, or a general IQ, appeared to be largely preserved following varying extents of ACC as well as complete CC [corpus callosotomy] , with 27/30 cases across all reviewed studies for GIQ reporting a positive outcome (i.e. stable or improved)."  

Contrary to what we would expect from "brains make minds" claims, the people left with two divided brain hemispheres mostly maintained their intelligence at the same level, as measured on IQ tests. 

We hear no mention at all in the paper of anything like "two conscious minds in one skull" being the result of the corpus callosotomy that splits a brain into two separated hemispheres. The continued repetition of such false claims about split-brain operations by some neuroscientists should cause us to ask: in what other cases do brain experts blatantly misinform us?

A  scientific study published in 2017 set the record straight on split-brain patients. The research was done at the University of Amsterdam by Yair Pinto. A press release entitled “Split Brain Does Not Lead to Split Consciousness” stated, “The researchers behind the study, led by UvA psychologist Yair Pinto, have found strong evidence showing that despite being characterised by little to no communication between the right and left brain hemispheres, split brain does not cause two independent conscious perceivers in one brain.”

The press release states the following: “According to Pinto, the results present clear evidence for unity of consciousness in split-brain patients.” The paper states, “These findings suggest that severing the cortical connections between hemispheres splits visual perception, but does not create two independent conscious perceivers within one brain.”

Searching on Google Scholar for the term "corpus callosotomy" which describes the operation cutting the corpus callosum and separating the brain into two halves, I find several other long systematic reviews and meta-analysis papers, none of which say anything about any "two conscious minds in one skull" effect. Another example is the paper here. Should we believe that all those very many pages discussing the effects of this operation would fail to mention it producing a "two conscious minds in one skull" effect so spectacular and important, if it actually occurred? No, we should not. It's far more credible that neuroscientist Christof Koch simply told us a groundless "old wives' tale" to try to prop up some narrative claiming brains make minds. 

See my post here for a citation of many other scientific articles and scientific papers debunking the groundless myth that split-brain operations produce "two conscious minds in one skull."

Split-brain patients who underwent surgery to split their brains are not the only people with two separated brain hemispheres. Sometimes split-brain subjects arise when the corpus callosum fails to form during the mother's pregnancy. This is called agenesis of the corpus callosum. Making a generalization about people born without a corpus callosum connecting the two sides of the brain, a scientific paper states this:

"The major anatomic feature of Primary AgCC  [agenesis of the corpus callosum] is the absence of the corpus callosum....Primary AgCC has surprisingly limited impact on general cognitive ability. Although the full-scale IQ may be lower than expected based on family history, scores frequently remain within the average range."

We hear no mention of any "two minds in one body" effect. Another paper states this, using the term "agenesis of the corpus callosum" which means a failure of someone's body to ever have  the corpus callosum connecting the two halves of the brain:

"In the 37 adult cases of agenesis of the corpus callosum, 19 (51%) had some degree of intellectual impairment, with the remainder being judged to have a normal IQ. Of those with learning difficulties, two thirds had a mild impairment, and one third had a moderate or severe problem."

So roughly half of these 37 split-brain people had a normal IQ. You can find papers on the condition of being born with no corpus callosum by searching on Google Scholar for papers having the phrase "agenesis of the corpus callosum."  You will not find any discussion of "two minds in one body" in such papers about split-brain subjects, which helps show that the claim of such an effect is groundless.   

Be Skeptical of "Consciousness in Comatose" Claims, Which Are Probably More Brain Expert Pareidolia

Neuroscientists often make groundless boasts of having discovered things in brains that are not actually there. What is going on is pareidolia, people reporting seeing something that is not there, after wishfully analyzing large amounts of ambiguous and hazy data. It's like someone eagerly analyzing his toast every day for years, looking for something that looks like the face of Jesus, and eventually reporting he saw something that looked to him like the face of Jesus.  It's also like someone eager scanning the clouds, looking for animal shapes, while trying to confirm his belief that after an animal dies, his ghost goes up and lives in the clouds. 

On this blog I have provided very many examples of neuroscientist pareidolia. Some examples can be found in my posts here: 

Neuroscientists Claim "Drifting Representations," But It's Mainly Just Their Pareidolia

Pareidolia Progress: Neuroscientists Get Better and Better at Seeing Things in the Brain That Are Not There

Pareidolia Helps Neuroscientists Getting Nowhere Trying to Show a Brain Basis for Memory

Some Brain Wave Analysts Are Like "Face of Jesus in My Toast" Claimants

Normally when neuroscientist pareidolia occurs it is relatively harmless. There is the epistemic harm and intellectual harm caused when bad evidence is provided of things that are not true, but little other harm. However, one type of neuroscientist pareidolia can cause bad psychological harm in the relatives of those who are in a coma. I speak of the case of neuroscientists making shoddy claims of having discovered consciousness in comatose patients. 

We read some examples in a Harvard Medicine article entitled "The Covert Consciousness Dilemma." The article is written by someone falling "hook, line and sinker" for some very dubious claims that were never well-supported.  Early in the article the writer states this:

"Around the same time, Edlow heard about a paper published in Science that stunned him. The 2006 study focused on a patient who sustained extensive brain injuries following a traffic accident. Six months later she was still in a vegetative state. She showed no evidence of purposeful behaviors, such as following commands or making intentional movements. But then the researchers put her in an fMRI machine. While scanning her brain, they asked her to imagine walking through her house, moving slowly from room to room. And they told her to imagine playing a game of tennis, swinging for the ball with forehand and backhand strokes... Her brain responded to the commands with activity patterns that matched those of a healthy person, as if to say, I’m still here."

The 2006 study referred is the very low-quality paper "Detecting Awareness in the Vegetative State," which fails to provide any decent evidence justifying its title. The paper provides no robust evidence that any consciousness was detected in the single subject it studied. The paper claims that "Speech-specific activity was observed bilaterally in the middle and superior temporal gyri, equivalent to that observed in healthy volunteers listening to the same stimuli (fig. S1)." The Figure S1 referred to is one of those extremely misleading visuals in which neuroscientists artificially color-highlight particular regions of the brain that showed only tiny differences such as 1 part in 200, to create the false impression that there was some big difference in brain activity in some region which merely had a difference such as 1 part in 200. 

Here is the Figure1 of the paper 

This visual is not a visual produced directly from any brain scan. The visual was produced through a process of artificial construction designed to make tiny differences such as 1 part in 200 look like big differences. Such methods are misleading. A correct visual showing the brain activity would show differences that cannot even be recognized by a human. 

The authors of the paper fail to caption their Figure 1 correctly. They say that it shows what occurred during "tennis imagery in the patient," even though they have no evidence that any tennis imagery was occurring in the mind or brain of their comatose patient when this scan was taken. Looking closely at Figure 1 above, we fail to even see any close match. The highlighted regions in the first row look significantly different from the highlighted regions in the second row. No good evidence has been provided that any such thing as "tennis imagery" or consciousness was occurring in the patient. 

There is actually no evidence in the literature of neuroscience that there exists any such thing as a neural correlate of imagination. If you scan someone's brain while asking him to keep a blank state of mind, and compare the scans to scans taken while the person was asked to imagine something, you will see no difference if the person kept perfectly still. There will be variations here and there such as 1 part in 200, but such variations can be explained as mere random variations, rather than something that resulted from an act of imagination. Muscle movements do produce blips in EEG readings and fMRI scans, but such blips are not evidence of thinking. 

The paper "Neural substrates of envisioning the future" describes a study looking for neural correlates of imagination. 21 subjects were brain scanned while they did three tasks: remembering an event in their past (such as a birthday in the past), imagining an event in their future (such as a future birthday they would have), or imagining an event in someone else future.  Figure 1 shows unimpressive results, with percent signal changes no greater than about 1 part in 200, which are the kind of differences one would expect to get from random fluctuations, even if people don't use their brains for imagining or remembering.  We read of a "statistically indistinguishable pattern of activity across time while subjects envisioned their personal future (SF) and recollected the past (SR) in response to a series of event cues (e.g., Birthday)."  The results when people were "imagining a future individual in similar scenarios" also fail to show any clear sign of neural involvement, with percent signal changes no greater than about 1 part in 200.  

 The low-quality paper "Detecting Awareness in the Vegetative State" fails to provide any decent evidence for consciousness in the comatose. To have decent evidence for such a thing, you would need a much larger sample size than the paper's way-too-small sample size of a single subject. The authors are guilty of runaway pareidolia when they claim this about their comatose patient "Moreover, her decision to cooperate with the authors by imagining particular tasks when asked to do so represents a clear act of intention, which confirmed beyond any doubt that she was consciously aware of herself and her surroundings." They have provided no decent evidence of either imagination, intention, cooperation or consciousness in the comatose patient they brain scanned.  The authors engage in the old fallacy of claiming that "significant activity was observed" in particular brain regions when the subject was asked to imagine something. All brain regions are continually active in any living patient with a heartbeat, so showing that "significant activity was observed" in particular brain regions does nothing to show consciousness, intention or imagination. 

We then have in the Harvard Medicine article an emotional quote from neurologist Brain Edlow saying that this low-quality paper "just blew my mind," followed by the groundless claim that this paper "completely reframed the way that we think about consciousness and opened up the possibility that a substantial number of patients may be conscious even if we cannot detect purposeful behavior at the bedside." Once again, we have a brain expert getting all super-excited over the flimsiest of evidence. 

The Harvard Medical article then refers us to a 2024 paper with a larger size, the paper "Cognitive Motor Dissociation in Disorders of Consciousness." The paper is one of those deals in which you have a claim of a fairly large sample size, but the claim is made by adding up the study group sizes in a bunch of papers, which all used very small samples. 

The two sentence abstract of the paper starts out by making unfounded claims, saying this:

"Patients with brain injury who are unresponsive to commands may perform cognitive tasks that are detected on functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). This phenomenon, known as cognitive motor dissociation, has not been systematically studied in a large cohort of persons with disorders of consciousness."

No such phenomenon has ever been established by high-quality studies, and this paper is not any such high-quality study. The "detection" it refers to are very likely example of pareidolia or errors-to-be-expected, in which over-eager researchers see things that are really there, because of a biased interpretation of borderline, varying data in which an over-eager analyst could see 101 things that are not really there. 

The authors claim, "We detected cognitive motor dissociation in 60 of the 241 participants (25%) without an observable response to commands, of whom 11 had been assessed with the use of fMRI only, 13 with the use of EEG only, and 36 with the use of both techniques."  The visual below shows the type of devices used. 

The paper incorrectly states, "Cognitive motor dissociation is an established phenomenon in which persons with severe brain injury who are behaviorally unresponsive to commands show brain activation on functional magnetic resonance imaging (fMRI) or electroencephalography (EEG) when presented with cognitive tasks, such as motor imagery commands." No robust evidence has ever shown the existence of such a "cognitive motor  dissociation" phenomenon. 

Supplementary Figure S4 (in the Supplementary Information of the paper) gives us an indication of how weak the evidence of this paper is. The figure refers to a CRS-R scale that is a measure of how deeply someone is in a coma. According to an AI overview, "A total score of ≥ 8 generally indicates a transition from a vegetative state to a minimally conscious state, while a score of ≥ 10 helps identify patients who have achieved emergence from a minimally conscious state." The Figure S4 graph below shows no robust evidence of  any responses from any patients with a score of less than 11 on this CRS-R score. Below is the graph:

The left half of the graph plots responses in those being in stronger and deeper comas. The right half of the graph shows responses in those who are not fully comatose.  The claimed evidence for responses (as detected by fMRI or EEG activity) is found in the bar sections that are light blue or pink. 

But as you can see by closely studying this graph, there is almost no pink or light blue color in any of the bars on the left half of the graph. Any of the very small pink areas we see in the left half of the graph above can easily be explained as being mere pareidolia or garden-variety analysis error from over-eager researchers eager to report "responses" after analyzing data that did not actually show any good evidence of a response. 

So we see the "secret sauce" behind this paper "Cognitive Motor Dissociation in Disorders of Consciousness." It may have some got some evidence of responses from the subjects that underwent scanning by fMRI scanning or EEG scanning. But almost all of those claimed responses come from those not fully comatose (those scoring higher than 10 on the CRS-R scale). No strong evidence has been produced of responses or cognition or imagination or will in any of those who are fully comatose (the people graphed on the left half of the graph above). 

Normally the misleading language and "see what you are hoping to see" pareidolia of brain experts is fairly harmless. But in this case such pareidolia is extremely harmful. The people doing low-quality studies like this are causing the relatives of those in a coma to needlessly fear that their relatives are enduring what many would regard as a fate worse than death: a fate of being conscious in a body when you cannot open your eyes and cannot move your muscles.  There is no robust evidence that anyone in a coma is suffering such a fate. "Eager for another paper publication" brain experts are causing needless mental anguish in the relatives of those in comas, by groundlessly causing them to fear their relatives are undergoing some horrible fate, when there is no sound evidence basis for such fears.  When studying such papers, we should always remember that brain experts studying the ever-varying data from fMRI scans and EEG readings have a long history of frequently claiming to see things that are not really there, and a long history of conjuring up phantasms that don't really exist. 

You cannot actually tell whether someone is imagining something by looking at EEG readings taken from such a person's brain or by looking at fMRI scans. Studies that claim to provide evidence for such a thing are often studies that improperly leverage EEG traces of muscle movements. If you give someone an instruction such as "imagine yourself playing tennis," a person might well make subtle movements matching such thoughts, movements that show up in EEG readings. Evidence of muscle movements are not evidence of imagination. No one disputes that muscle movements produce EEG blips. 

A look at one of the papers referenced by the "Cognitive Motor Dissociation in Disorders of Consciousness" paper shows the kind of arbitrary and convoluted statistical rigamarole that was going on to gin up some of these claims of "responses" in comatose patients being spoken to:

"We used two complementary methods to determine the significance of differences in the frequency content of the EEG signal between the task and rest conditions: a univariate (frequency-by-frequency) approach and a multivariate approach. For each subject, both analyses were applied on a channel-by-channel basis to each run individually and to all runs combined.

For the univariate approach, we used a z-statistic, the Two Group Test (TGT) (Bokil et al., 2007), as implemented by the Chronux toolbox routine, two_group_test_spectrum (http://chronux.org), with a cutoff of p≤0.05 by jackknife method. Because spectral estimates within 2 Hz of each other are correlated by the taper functions, a difference identified by the TGT was only considered significant if it was present for all frequencies contiguously over a range greater than 2 Hz. This implies significance over at least two neighboring but non-overlapping windows of the multi-taper estimate and is indicated in figures with a rectangle drawn around the results (Figure 3B). Spectral differences over ranges narrower than 2 Hz represent only a trend to significance. To compensate for multiple comparisons (60 frequencies per channel in 29 or 37 channels), the False Discovery Rate (FDR) (Benjamini and Hochberg, 1995; Benjamini and Yekutieli, 2001) was applied to the TGT p-values determined from analyses of all runs combined.

To look for spectral differences that might only be apparent if combinations of frequencies are considered, we employed a multivariate approach, Fisher’s linear discriminant (FLD) (Fisher, 1936). This approach has been used successfully for classification of EEG responses to motor imagery (Hung et al., 2005; Bai et al., 2007). To limit dimensionality, we binned the log spectra from 4 to 24 Hz into 2 Hz windows, reducing the spectrum to 10 values. The FLD was then defined as the linear combination of these quantities that maximized the ratio of the power variance between the conditions to the power variance within the conditions. To determine the significance of the FLD, we used a shuffle method: we recomputed the FLD from 1000 shuffles of the two conditions, and determined the p-value as the fraction of shuffled datasets that yielded an equal or larger value to the actual FLD. To take into account the possibility that neighboring snippets had similar spectra because of a slowly changing underlying brain state (rather than the task) (Menzer et al., 2010), the shuffled datasets kept the snippets from the nine-second-response period after each command together during all shuffles. To control for multiple comparisons (since the FLD was applied separately to each channel), the FLD p-value was only considered significant for a channel if it was less than an FDR-corrected rate of 0.05. This is shown as an asterisk on the summary figures (e.g. channel Oz in Figure 3B). For each subject, this analysis was applied to each run individually, and to all runs combined."

Of course, when researchers are free to use "keep torturing the data until it confesses" methods like these (methods as arbitrary, convoluted and opaque as the researchers may wish), it is hardly a surprise that there might be conjured up here and there a little so-called "response evidence," even when data from the brains of utterly unconscious coma patients is being analyzed. 

So many ways to conjure up phantasms that don't exist