HALLUCINATIONS
NATURAL VS. DRUG-INDUCED
•Akshay Chandra
•Jarrod Hyam
•Maria Mann
•Jenny Pranskevich
OUTLINE
•
Introduction
•
Maria
– Natural Hallucinations
•
Jarrod
– Mystical Hallucinations
•
Shay
– Hallucinogens
•
Jenny
– Conclusion
What is a Hallucination?
• A hallucination is the brain's perception of
a false sensory input
• Experiencing of an event through one of
their senses that is not occurring in the
real world
–
–
–
–
Visual
Auditory (hearing one’s thoughts as if spoken aloud)
Tactile
Olfactory
CAUSES
• Natural:
•
•
•
•
Meditation
Sensory Deprivation
Dreams
(Schizophrenia, Dementia, Exhaustion,
Brain Tumors)
• Drug Induced
–
–
–
–
LSD
DMT
Mushrooms
MDMA
Meditation
During mediation the attention is
brought into the field of the unconscious
mind for extended periods of time.
When the brain lacks external
stimulation to form perceptions, it may
compensate by referencing the memory
and forming hallucinatory perceptions.
Meditation/Neural Correlates
• Meditation is correlated with increased
5HT Seratonin, a neuromodulator that
influences the flow of visual
associations generated by the temporal
lobe. When 5HT2 receptors are
activated, a hallucinogenic effect can
result. 5HT inhibits the LGN, reducing
the amount of visual info that passes
through.
• When combined with reticular nucleus
inhibition, 5HT may increase the fluidity
of temporal visual associations in the
absence of sensory input.
Sensory Deprivation
If one eliminates
external sources of
low-level pain and
sources of danger,
the inner experience
can be anything one
allows itself to
experience.
Hallucinations & Dreams
• Hypnagogic hallucinations are short,
usually auditory hallucinations that occur
when a person is falling asleep.
• Hypnopompic hallucinations occur when a
person is waking up.
Dreams/Neural Correlates
• When relative activation of 5HT2 to 5HT1
was reduced, REM sleep was suppressed.
Therefore, relative activation of 5HT2
pathways are implicated in REM sleep.
The subjective experience of dreaming is
likely a result of 5HT2 activation, much like
the pathway responsible for the effects of
etheogenic drugs.
Perception Hallucination
Continuum
Both natural and drug induced states are marked by a
gradual turning inward toward a mental dimension at the
expense of the physical.
Left-Right Hemispheric Switch
Data processing is
preferentially
shifted to the
visuospatial, right
hemisphere when
one departs on the
perceptionhallucination
continuum naturally
or via
hallucinogenic
drugs.
Mystical States
• Specific form of hallucinatory experience
• Main characteristics are:
1.) Ecstatic mood
2.) Sense of newly gained
knowledge about reality
3.) Perceptual alterations
4.) No sense of space or time
5.) Unity with all of life
Good Friday Experiment - Pahnke
•Investigated the potential of hallucinogens to facilitate
mystical experience
•Double-blind experiment:
–Twenty theology students, who had never taken psilocybin
given either placebo or 30mg psilocybin during a Good Friday
Church Service
PSILOCYBIN
•
• A questionnaire was given after the experiment
• Subjects in the control group reported:
a.) 5% internal unity, 1% external unity
b.) 7% transcendence of time and space
c.) 23% deeply felt positive mood
• Experimentals reported:
a.) 60% internal unity, 39% external unity
b.) 78% transcendence of time and space
c.) 54% deeply felt positive mood
Neurochemical Theory for Mystical
States
• Synthesis of endogenous hallucinogen 5methoxy-dimethyltryptamine (DMT) from
the pineal gland
• DMT is Part of the Tryptamine Family:
– Tryptamines are alkaloids with an indole structure
– Other hallucinogenic tryptamines include LSD and psilocybin
– These compounds have a cultural context of mystical-state
induction
Hallucinogens
LSD (Lysergic Acid Diethylamide)
MDMA (3,4-methylenedioxymethamphetamine )
2-CB (4-bromo-2,5-dimethoxyphenethylamine )
Psylocybin (Mushrooms)
MDMA
Dosage: 80 -150 mg
Onset: 30 – 60 minutes
Duration: 3 – 4 hours (if
taken orally)
Effect: emotional openness,
euphoria, stimulation,
reduction of critical and
cynical thoughts, and
decrease of inhibitions
few prominent open or
closed eye visuals, only a
small percent report
significant visual
distortions.
2C-B
Dosage: 10 – 40 mg
Onset: 45 – 75 minutes
Duration: 4 – 6 hours
Effect: a wide variety of
perceptual changes may
occur; pupil dilation,
visual patterning and
movement, mental
stimulation, new
perspectives, feelings of
insight, emotional shifts
(mood lift or
introspection), anxiety
and confusion
Psilocybin
Dosage: 1-5 grams of dried
mushrooms
Onset: 30- 60 minutes
Duration: effects last 4- 6
hours
Effects: pupil dilation,
visuals, mental
stimulation, new
perspectives, feelings of
insight, quickly changing
emotions (lots of
laughter), possible
paranoia and confusion
LSD
Threshold: 20 micro
grams
Dosage: 50 - 150 micro
grams
Onset: 30 – 120
minutes
Duration: 6 – 14 hours
Effect
- In the beginning stages: feeling similar to
anticipation or anxiety, a slight feeling of energy
in the body, an extra twinkle to lights, or the
feeling that things are somehow different than
usual.
- As the effects become stronger: non-specific
mental and physical stimulation, pupil dilation,
closed and open eye patterning and visuals,
changed thought patterns, feelings of insight,
confusion, or paranoia, and quickly changing
emotions.
Neurological effect
• Ungerleider and Pechnick
concluded that LSD and
similar hallucinogenic
agents work by an
agonist effect at the 5HT2 receptor
• LSD not only has
affinities for 5-HT
receptors but also for
receptors of histamine,
ACh, dopamine, and the
catecholines: epinephrine
and norepinephrine
LSD binding at 5-HT2 receptor
Receptors and brain physiology
• convergent evidence shows that there is
a high concentration of 5-HT-2 receptors,
and of hallucinogen binding in the
claustrum
• The V1 target zone in the claustrum
appears to overlap to some degree with
those of higher order visual areas, which
are specialized for the processing of
motion, color, and form, and with areas of
parietal and prefrontal cortex that have
been implicated in attention, working
memory, and the generation of eye
movements
Potential explanation for LSD
hallucinations
• integrity of the visual cortico-claustral loop may be
necessary for precise temporal integration of edge
information from end-inhibited and line-detector cell
populations, and that the nature of this temporal coding
may be modulated based on the expected motion of
objects, eye movements, and selective attention.
• Therefore, the dysfunction of inhibition in these areas
caused by psychedelics may, at least in part, mediate
the visual distortions they produce.
CONCLUSIONS
• THEORIES
– Serotonin and 5-HT2 Receptors
• Indole Rings
– Sensory overload
• Visual hallucinations not produced in patients who
have a severed optic nerve
SEROTONIN PATHWAYS
• serotonin pathways innervate
different brain regions.
• the Raphe nucleus
– long axons project to higher
centers in the brain including
the neocortex and the limbic
system (e.g., the amygdala
and hippocampus
• Second pathway that goes
down brainstem
SEROTONIN RECEPTORS
• Serotonin has several classes of different
binding sites
• 5HT1 Receptors: Regulates serotonin levels
• 5HT2 Receptors: stress management
• 5HT3 Receptors: “Happiness”
5-HT2 Receptors
• Found on the post-synaptic neuron
• G-protein-coupled
• Typically inhibited by hallucinogenic drugs
– More difficult to generate an action potential
INDOLE RINGS
•
M
Serotonin
Mescaline
LSD
Psylocibin
DRUGS DON’T DO
ANYTHING TO THE BRAIN
THAT THE BRAIN CANT
DO TO ITSELF
RESOURCES
•
Altman, Christopher. “Neuropharmacology of the Mystical State.” http://artilect.org/altman/mysticism.html
May 30, 2005
•
Bourgeois, James, DeJuan Thomas, Johansem Thomas, and David Walker. “Visual Hallucinations
Associated With Fluoxetine and Sertraline.” Journal of Clinical Psychopharmacology: 18(1998): 482-483
•
Doblin, Rick. “Pahnke’s ‘Good Friday Experiment’: A Long-Term Follow-Up and Methodological Critique.”
The Journal of Transpersonal Psychology. 23 (1990)
•
Ffytche, Dominic. “Visual Hallucination and Illusion Disorders: A Clinical Guide.” Advances in Clinical
Neuroscience and Rehabilitation. 2004. (4) 16-18. Frith, Chris, and Ray Dolan. “The Role of the Prefrontal
Cortex in Higher Cognitive Functions.” Brain and Cognition. 5 (1996): 175-181.
•
<http://www.erowid.org/archive/rhodium/pharmacology/visualdistortions.html> May 30, 2005
•
<http://sulcus.berkeley.edu/mcb165/_Archives/mcb165sp97tPaper/mcb165sp97R.manuscript/_822.html>
May 30, 2005 <http://www.cs.hmc.edu/~ivl/writing/non_fiction/lsd/> May 30, 2005
•
<http://www.healthatoz.com/healthatoz/Atoz/ency/hallucinations.jsp> May 30, 2005
•
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•
Newberg, Andrew B. & Iversen, J. “The neural basis of the complex mental task of meditation:
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•
Ramachandran, V. S. and R. L. Gregory (1991). Perceptual filling in of artificially induced scotomas in
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RESOURCES CONT.
•Scott, Foresman. Behavioral Analysis of Drug Action. Ed. John A. Harvey. Glenview, Illinois, 1971.
•Siegle, Ronald. Fire in the Brain: Clinical Tales of Hallucination. New York: Penguin Books, 1992.
• Siegle, Ronald, and L.J. West. Hallucinations: Behavior, Experience, and Theory. New York: John Wilsey &
Sons, 1975.
•Wallace, Benjamin and Leslie Wallace. Consciousness and Behavior 4th Ed. Prospect Heights: Waveland
Press, 1999.