Transcript Baars - neurofeedback - Aspen2008

Conscious experiences trigger
widespread adaptive changes in the human brain:
The case of conscious neurofeedback.
Bernard J. Baars
The Neurosciences Institute
San Diego
www.nsi.edu/users/baars
Train movie -
Available for download from:
www. bernardbaars.pbwiki.com
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How can scientists study consciousness?
“The study… of the distribution of
consciousness shows it to be exactly such as we
might expect in an organ added for the sake of
steering a nervous system grown too complex to
regulate itself.”
--- William James,
The Principles of Psychology,
1890, p. 141
That is, we need to study contrastive
cases… allowing experimental
comparisons between closely matched
conscious and unconscious conditions.
Wiliam James (1842-1910)
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As William James recommended,
we compare similar conscious and unconscious conditions --- it's
"the distribution of consciousness" that can reveal its functions.
(Rees, Koch & Kreiman, 200x)
Binocular rivalry permits close
comparisons between conscious vs.
unconscious input streams
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Global Workspace Theory.
Conscious experiences evoke brain-wide distribution
of focal (conscious) contents.
Evidence from:
fMRI (Dehaene, Rees,
etc),
Episodic learning
MTL-neocortex'
Global broadcasting
of conscious visual
contents
NN Models & large-scale
simulations;
EEG evoked potentials
(Revonsuo, Dehaene),
Visual
cortex
Visual
cortex
Waking vs. unconscious
EEG;
… and
THE VERY WIDE
REACH OF
conscious
NEUROFEEDBACK.
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A remarkable range of conscious N-feedback phenomena.
(neurofeedback = brain-based biofeedback; Baars, 1988, etc.) (PubMed refs: about 7,000).
Feedback must be conscious --almost everything else is not.
GWT suggested that conscious feedback from the brain-triggered
display is broadcast globally, so that motor networks can act locally to plan
and trigger voluntary actions --- unless they encounter inhibition.
(Technically: "local processing initiative in a highly distributed society of
parallel processors"; Baars, 1988)
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A very large range of brain activities
are modifiable by conscious N-Feedback.
(Baars, 1988, etc)
In animals --- learned, voluntary control of almost any arbitrary SINGLE
NEURON, or almost any arbitrary POPULATION of neurons has been reliablr
reported for about fifty years.
[misleadingly called "Operant conditioning"]
In humans, control of alpha EEG. EMG & nl autonomic functions has been
long known.
Newer findings: conscious neurofeedback learning has been reported for:
1.
2.
3.
4.
5.
6.
EEG --- almost any brain rhythm, frequency band or scalp location, singly
or combined. Alpha-gamma coupling, synchrony, desynchrony, etc.
Brain rhythms associated with specific brain functions, like memory
recall, executive functions, sleep and motor control.
Normative EEG patterns associated with specific human populations, both
normal and dysfunctional. (Using QEEG and similar methods.)
Intracranial recordings (Loreta)
Evoked brain activity, including evoked synchrony and desynchrony.
fMRI --- BOLD activity in local cortical regions, e.g., anterior insula.
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A great range of health conditions
have been reported to be modifiable by conscious N-feedback.
1.
2.
3.
4.
5.
6.
7.
ADD/ADHD in children and adults - using slow cortical potentials
Epileptic brain activity
Cognitive functions, IQ, and musical performance (JAMA, 2006)
Autistic spectrum signs
Obsessive-Compulsive Disorder (OCD)
Tinnitus (ringing in the ears), and insomnia.
Improvements in psychiatric disorders, depression and schizotypy, auditory
hallucinations.
8. Anorexia and bulimia
9. Bladder control, heart-rate, blood pressure,
10. Chronic pain, fibromyalgia - cortical pain may depend on slow rhythms.
This is not to say that these are mature, well-tested treatments. However, the
very wide range and robust short-term effects are quite remarkable. They tell
us something fundamental about consciousness, and suggest important
practical applications.
A lot more basic science studies are needed!
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How is this possible? The ideomotor hypothesis.
Motor regional
assembly is
triggered by
broadcast image
….
Ideomotor hypothesis:
Conscious feedback from
the brain-triggered visual
display is hypothesized to
be broadcast globally, and
local unconscious motor
routines act to plan and
trigger voluntary actions --unless they encounter
conscious inhibition.
(Baars, 1988, 2002, etc.)
Conscious
image is
broadcast ….
Note: The feedback signal must be conscious, but it doesn’t
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matter what kind of signal is used - sense modality, pattern, etc.
Neurofeedback training seems to require:
• A distinctive brain signature, linked to the
behavior of interest.
• Conscious feedback with minimal time delay.
(A few seconds).
•Any kind of conscious feedback stimulus
seems to work.
• Minimize distraction and noise.
• The target behavior should not be tightly bound
by homeostatic limits. (e.g. heart rate, etc.)
• Gradual steps to the goal.
• Incentives to keep learning, spaced practice
sessions over time, adequate sleep and rest
periods, and so on.
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Conscious neurofeedback demonstrates
exactly the opposite of "epiphenomenalism"
--- the notion that consciousness does nothing useful.
"Epi-phenomena-l-ism" as defined by T.H. Huxley:
"Consciousness would appear to be related to the
mechanism of the body … simply as a [side-] effect of its
working, and to be completely without any power of
modifying that working, as the [sound of] a steam whistle
which accompanies the work of a locomotive … is without
influence upon its machinery."
The uselessness of consciousness was enormously
widespread in behaviorism. Some philosophers and scientists
still favor it --- because they don't look at contrastive evidence.
Thomas Henry Huxley - 1874
"Darwin's bulldog."
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Consciousness is some steam whistle!
William James
up and dancing
…
all because of a
conscious idea!
William James unable to get off his couch…
"We know what it is to get out of bed on a freezing morning in a room without a fire,
and how … we say,"I must get up, this is ignominious," etc; but still the warm couch
feels too delicious, the cold outside too cruel, and resolution faints away...
Now how do we ever get up under such circumstances? … We suddenly find that we
have got up. A fortunate lapse of consciousness occurs; we forget both the warmth and the
cold;… the (spontaneous) idea flashes across us, "Hollo, I must lie here no longer" --- an idea
which at that lucky instant awakens no contradictory or paralyzing suggestions, and
consequently produces immediately its appropriate motor effects. ... This case seems to me to
contain … the data for an entire psychology of volition. ..."
--- William James, 1890, on the ideomotor theory of voluntary control.
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James' ideomotor theory fits easily
into Global Workspace Theory.
(Baars, 1988, etc)
ideomotor theory. The notion that conscious goals and images
are inherently impulsive, and tend to be carried out by default,
unless they are inhibited by other conscious thoughts or
intentions.
This theory can be straightforwardly incorporated into GW
theory, and helps to explain basic features of voluntary action
… (7.3).
--- Baars, 1988, A Cognitive Theory of Consciousness, Glossary
Bottom line: "Conscious experiences provide
the primary adaptive input to the brain: The
evidence shows omni-phenomenalism,
not epi-phenomenalism.
Conscious experience is very powerful. (Slide 6)
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Basic science questions to be answered.
1. What range of brain events can come under voluntary
control? A "Strong GWT" claim suggest that any neuron
not under very high local constraints can come under
voluntary control.
2. When sensory feedback is UN-conscious but not
blocked from sensory receptors, will feedback learning
fade in a dose-response fashion? (Strong GWT
hypothesis)
Testable prediction: The arbitrary intracranial matrix.
In an intracranial grid of electrodes, one
should be able to select any arbitrary
subset of electrodes to give feedback to,
the others being inhibited. (Basmajian,
1961). If that is possible, and if UNconcious perceptual feedback cannot be
learned, the implication is that the concious
feedback must be very widely distributed.
(GWT)
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Neurofeedback is not the only kind of learning or brain adaptation
enabled by conscious experiences…
1.
Episodic memory: the MTL-neocortical system involves conscious input and recall.
2.
Semantic memory is believed to "ride" on the conscious episodic memory system.
3.
Perceptual learning always involves conscious contents.
4.
Procedural learning appears to require conscious access during acquisition, and then
becomes less conscious with practice, coinciding with less cortical involvement.
5.
Experience-dependent plasticity - reorganizes cortex. --- but scientists still avoid the
word 'conscious experience'. They also don't run the unconscious controls.
6.
Working Memory appears to require consciousness of transitions. (Baars & Franklin,
2003, TICS).
7.
There are some demonstrated cases of unconscious input processing and possibly
learning. For historical reasons, the professional payoffs are far greater for demonstrating
unconscious learning than for consciously-mediated learning. Both are obviously
important.
In sum, the evidence for the role of conscious experiences in brain adaptation is even
more widespread than neurofeedback.
Consciously-mediated learning is the norm, not the exception.
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Experimental results:
Wide forward activation due to conscious visual input, but not unconscious.
From Dehaene et al, 2001
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