Certain
stories crop up in the scientific literature, and persist year after
year despite a lack of solid basis in fact. One such story is that
Galileo threw spheres of different weights from the Leaning Tower of
Pisa to test whether they would reach the ground at the same time. A
wikipedia.org article on the experiment says such an experiment
(never reported by Galileo) probably never occurred.
Another
such story is the idea that Darwin found evidence for his ideas about
evolution in finches he studied at the Galapagos Islands. Page 35 of
a long paper on the topic by a Harvard scientist (entitled “Darwin and His Finches: The
Evolution of a Legend” ) states Darwin “never actually put
finches forward as evidence for the theory of evolution.” Page 39
states this:
In
spite of the legend’s manifest contradictions
with historical fact, it successfully holds sway today in the major
textbooks of biology and ornithology, and is frequently encountered
as well in the historical literature on Darwin. It has become, in
fact, one of the most widely circulated legends in the history of the
life sciences, ranking with famous stories of Newton and the apple
and of Galileo’s experiments at the Leaning Tower of Pisa.
On
page 134 of his recent biography of Darwin, A.N. Wilson states the
following:
Peter
and Rosemary Grant, evolutionary biologists from Harvard University,
spent twenty-five summers studying these birds....They revealed that
the beak changes were reversible -- this is hardly 'evolution.'
Beaks adapted from season to season, depending on whether droughts
left large, tough seeds, or heavy rainfall resulted in smaller,
softer seeds.
A
legend that arose fairly recently is that split-brain patients
patients have a splitting of their perception, or maybe something
like “split consciousness.” Such an idea was based on research
done by Roger Sperry and Michael Gazzaniga. A split-brain patient is
a patient who has a severing of the corpus callosum, a mass of
fiber-like nerves that connect the left hemisphere of the brain and
the right hemisphere of the brain.
Even
though split-brain patients continued to show a unity of
consciousness, and did not by any means show something like a split
personality, materialists have tried to make as much hay as possible
out of the research of Sperry and Gazzaniga. For example, in 2007
psychologist Steven Pinker claimed that “Surgery that severs the
corpus callosum, separating the two hemispheres (a treatment for
epilepsy), spawns two consciousnesses within the same skull,” and
spoke as if this alleged observation was evidence against a human soul. Such
a claim was bogus. None of the experimental results reported that
split-brain patients had two consciousnesses.
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.
On page 202 of his recent book "The Consciousness Instinct" neuroscientist Michael Gazzaniga claims that “a neurosurgeon can disconnect the
two hemispheres of the brain and produce two minds in your single
head.” The claim is false, and he provides no historical examples
of this happening. In
fact, on page 203 Gazzaniga refers to split-brain patients, and says,
“Oddly, after having their brains cut in half, all those patients
said they felt fine, and the only difference they noted was the loss
of seizures.” That statement contradicts his statement on page 202.
In
the video here we see a split-brain patient who seems like a pretty
normal person, not at all someone with “two minds." And
at the beginning of the video here the same patient says that after
such a split-brain operation “you don't notice it” and that you
don't feel any different than you did before – hardly what
someone would say if the operation had produced “two minds” in
someone. And the video here about a person with a split brain from birth shows us what is clearly someone with one mind, not two.
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.” Their paper had the visual below showing their results:
Pinto
and his colleagues criticize the research previously done on this
topic, saying the following:
Strikingly,
although this clinical observation features in many textbooks
(Gazzaniga
et
al.,
1998;
Gray,
2002)
the reported data are never quantitative...Sperry
notes: ‘Although the general picture has continued to hold up in
the main as described [… .] striking modifications and even
outright exceptions can be found among the small group of patients
examined to date.’
So
apparently the original researchers weren't very numerically precise in measuring
things, and got mixed results. Such nuances were ignored by a host of
writers eager to use Sperry and Gazzaniga's research as something to
prop up conventional dogmas that the brain generates the mind. Now
doing things in a proper quantitative way, Pinto and his colleagues
have come up with a result conflicting with the result of Sperry and
Gazzaniga, a result telling us that split-brain patients have a
perceptual unity of consciousness.
Pinto's
paper notes that his findings spell trouble for two theories of
consciousness, the Global Workspace Theory, and the Integrated
Information Theory, which are just flavors of the theory that brains
make minds:
This
preserved unity of consciousness may be especially challenging for
the two currently most dominant theories of consciousness, the Global
Workspace theory (Baars,
1988, 2005;Dehaene
and Naccache, 2001)
and the Integration Information theory (Tononi,
2004, 2005;
Tononi
and Koch, 2015).
A core assumption of the Global Workspace theory is that cortical
broadcasting of selected information by the ‘global workspace’
leads to consciousness. Thus severing of the corpus callosum, which
prevents broadcasting of information across hemispheres, seems to
exclude the emergence of one global workspace for both hemispheres.
Rather, it seems that without a corpus callosum either two
independent global workspaces emerge, or only one hemisphere will
have a global workspace, while the other does not. In either case, an
integrated global workspace, and thus preserved conscious unity,
seems to be difficult to fit into this framework.
The general prediction of the "minds come from brains" dogma would seem to be that if you split a brain so that the left half is not connected to the right half, this should result in two minds -- perhaps a "left half of the body in conflict with the right half of the body" situation. But no such thing occurs. After the split-brain operation there is still one consciousness and one self that at worst has some minor perceptual issues. The result of a unified consciousness in split-brain patients is perfectly compatible with the thesis of this website, that the human mind is not produced by the brain.
Postscript: See also this scientific paper "The Myth of Dual Consciousness in the Split Brain." The actual facts about split-brain surgery are related here by a surgeon who has performed such an operation. He states this about split-brain patients:
"After the surgery they are unaffected in everyday life, except for the diminished seizures. They are one person after the surgery, as they were before."
The surgeon states: "In a rational scientific community in which evidence and reason held sway, split-brain surgery would be hailed as compelling evidence for dualism and the immateriality of the intellect and will."
Physician Michael Egnor states the following about Sperry's research:
"The neuroscientist Roger Sperry studied scores of split-brain patients. He found, surprisingly, that in ordinary life the patients showed little effect. Each patient was still one person. The intellect and will – the capacity to have abstract thought and to choose – remained unified. Only by meticulous testing could Sperry find any differences: their perceptions were altered by the surgery. Sensations – elicited by touch or vision – could be presented to one hemisphere of the brain, and not be experienced in the other hemisphere. Speech production is associated with the left hemisphere of the brain; patients could not name an object presented to the right hemisphere (via the left visual field). Yet they could point to the object with their left hand (which is controlled by the right hemisphere). The most remarkable result of Sperry’s Nobel Prize–winning work was that the person’s intellect and will – what we might call the soul – remained undivided. The brain can be cut in half, but the intellect and will cannot. The intellect and will are metaphysically simple."
The recent article here in Psychology Today describes the bizarre experiment that was used to make the groundless claim that split-brain patients have two minds. It was some experiment based only on visual perception, using some experimental strange setup unlike anyone normally encounters. The article shreds to pieces claims that results from such an experiment shows that split-brain patients have two minds:
"Not so fast. There are several reasons to question the conclusions Sperry, Gazzaniga, and others sought to draw. First, both split-brain patients and people closest to them report that no major changes in the person have occurred after the surgery. When you communicate with the patient, you never get the sense that the there are now different people living in the patient's head.
This would be very puzzling if the mind was really split. Currently, you are the only conscious person in your neocortex. You consciously perceive your entire visual field, and you control your whole body. However, if your mind splits, this would dramatically change. You would become two people: 'lefty' and 'righty.' 'Lefty' would only see what is in the right visual field and control the right side of the body while 'righty' would see what’s in the left visual field and control the left side of the body. Both 'lefty' and 'righty' would be half-blind and half-paralyzed. It would seem to each of them that another person is in charge of half of the body.
Yet, patients never indicate that it feels as though someone else is controlling half of the body. The patients’ loved ones don’t report noticing a dramatic change in the person after the surgery either. Could we all — patients themselves, their family members, and neutral observers — miss the signs that a single person has been replaced by two people? If you suddenly lost control of half of your body, could you fail to notice? Could you fail to notice if the two halves of your spouse’s or child’s body are controlled by two different minds?"
A 2020 paper states this about split-brain patientis: " Apart from a number of anecdotal incidents in the subacute phase following the surgery, these patients seem to behave in a socially ordinary manner and they report feeling unchanged after the operation (Bogen, Fisher, & Vogel, 1965; Pinto et al., 2017a; R. W. Sperry, 1968; R. Sperry, 1984)."
A very relevant case reported is that of an 88-year old man (identified as H.W.) who tested very well on a test of mental functioning, getting the maximum possible score of 30. But it was found that the man had no corpus callosum. The corpus callosum is the main part of the brain that links the two brain hemispheres. A man who has no corpus callosum is equivalent to a split-brain patient. As an article reports:
"Given the importance of the callosum for connecting the bicameral brain, you’d think this would have had profound neuropsychological consequences for H.W. In fact, a detailed clinical interview revealed that he’d led a normal, independent life – first in the military and later as a flower delivery man. Until recently, if H.W.’s testimony is to be believed, he appeared to have suffered no significant psychological or neurological effects of his unusual brain...Brescian and her colleagues conducted comprehensive neuropsych tests on H.W. and on most he excelled or performed normally. This included IQ tests, abstract reasoning, naming tests, visual scanning, motor planning, visual attention and auditory perception."
The article has a very clear title telling us the truth about this matter:
This Elderly Man Was Born With His Brain Hemispheres Disconnected. Did It Affect His Life? Hardly.
But the corresponding scientific paper sounds as if was written to try and make this case as unlikely as possible to be noticed. We have this title: "Case study: A patient with agenesis of the corpus callosum with minimal associated neuropsychological impairment." Agenesis is a word meaning "absence," one that would only be used by someone trying to get as few people as possible to notice an absence. At least this language is not as bad as the outright lies that occur when materialist scientists tell us that splitting a brain into two unconnected hemispheres results in two minds.
No comments:
Post a Comment