Title: Schizophrenic and Psychedelic Hallucinations: The Neurophysical Enigma
1Schizophrenic and Psychedelic HallucinationsThe
Neurophysical Enigma
By Tim Keating
2Where It Occurs in our brain
Frontal Lobe Contains Prefronal
Cortex Prefrontal Cortex Takes sensory
information and Integrates with memory-
Amygdala PFC works with 5HT, among others to
inhibit Amygdala response.
Temporal Lobe Takes Visual and Auditory input
and re routes them to the frontal lobe and other
parts of the brain
Memory, Feelings, Incoming Stimulus and How to
respond to it all are disrupted
A hallucination is what occurs when there is a
change in the way information is being sent and
received in the brain from what is normal
3Schizophrenic Hallucinations
A few flavors 1. Auditory, 2. Visual, 3. Both
According to Hensley et al.(1981) the degree to
which an individual will experience a
hallucination is dependant on how much the
stimulus is present and how much attention the
subject is paying to it.Proves involvement of
PFC, but with so many circuits of COMPLEX
information flow, how can we see where the
problem is?
Hypofrontal activity reduced action in the
frontal cortex, but more on this later More
importantly, schizophrenia patients were found to
have accelerated membrane breakdown in the
temporal/frontal lobes. (glial cell involvement?)
Lots of disorders that cause hallucinations
Narcolepsy Cataplexy, Lewy body Dementia, Chales
Bonnet Syndrome (blind hallucinations), epilepsy
and schizophrenia
4Some Important Pathways
These pathways show flow of sensory information
and cortical connections and are each a potential
source of hallucinatory effects
5HT- Serotonin
5Some Important Pathways
These pathways show flow of sensory information
and cortical connections and are each a potential
source of hallucinatory effects
GABA
6Some Important Pathways
These pathways show flow of sensory information
and cortical connections and are each a potential
source of hallucinatory effects
Glutamate
7Some Important Pathways
These pathways show flow of sensory information
and cortical connections and are each a potential
source of hallucinatory effects
Dopamine
8More on Hypofrontality
fMRI Showing increased activity in association
cortex
Liddle 1996
SPECT showing increased activity
9A Study of Temporal Lobe Damage
- Disturbance of Auditory Sensation and Perception
- Disturbance of Selective Attention of Auditory /
Visual Input - Visual Perception Disorders
- Impaired organization and categorization of
verbal material - Disturbance of language comprehension
- Impaired long term memory
- Personality alteration
- Sexual behavior alteration
A wide variety of issues, conveniently they all
are so called symptoms of schizophrenia. All
patients who suffer from schizophrenia have
decreased Temporal and Frontal lobe volumes
(Marsh et al 1994)
10Pharmacological Approach
Clozapine- High affinity dopamine antagonist
Naloxone- High Affinity Opiod Antagonist
11Now that weve looked at the naturally occurring
hallucinations- its important to study drug
induced hallucinations as well.
- Drug induced hallucinations have lots of affects
on the human psyche which can be long lasting and
life changing- - Long theorized that religion and spiritual belief
may have been constructed during use of
hallucinatory drugs. - Other theories that complex intellectual
evolution may have had help from hallucinatory
drugs (5HT excitation in PFC and associational
cortex) - Helps to understand disorders in our own brain
between uniquely human areas - To help us stay in awe at the infinte complexity
of information transmission and integration of
the brain
The least controversial and the most helpful to
science.
12Interesting relationships
Drug induced hallucinations are for the most part
similar to all animals -Carne et. Al (2004) did
a study with hallucinatory drugs and mice and
found that drugs that were known to be
hallucinogenic caused head twitches in
mice. Schizophrenics have been known to have
decreased frontal lobe activity due to the
sporadic information being transmitted (either
too much or too little) and eventual Temporal
lobe degeneration due to so much
activity. Hallucinogenic drugs such as LSD,
Psilocybin and Mescaline are known to be 5HT
receptor agonists, which change the amount of
information being sent in the brain. Similar
effects- Theorized that using hallucinogenic
drugs in people with PFC disorders may help
treatment (hypoactivity of PFC mixed with
hyperactivity of 5HT receptors)
13Bringing it all together
Psilocybin and LSD are 5HT agonists.
Thank Hoffman, Even though drug induced
hallucinations and schizophrenic hallucinations
use different pathways, they both involve
information transmission to PFC and PFC activity
reduction
14Its not all flowers and sunshine
Even though people have had profound spiritual
and life changing realizations through use of
drug induced hallucinations, our understanding of
how these compounds work is still limited The
perfect example is Charles Manson, because of his
drug induced psychosis Its important
to remember that both schizophrenics and drug
abusers can suffer the same fate of induced
psychosis
http//www.youtube.com/watch?vXREnvJRkif0
15Articles Reviewed
- Varying Auditory Input on Schizophrenic
HallucinationsHenslet et al. 1981 the British
Journal of Psychiatry 139 122-127 (1981) - Functional imaging-schizophreniaLiddle P.F. 1996
Department of Psychiatry, University of British
Columbia, Vancouver, British Columbia, CANADA - Medial temporal lobe structures in schizophrenia
relationship of size to duration of illnessMarsh
et al. 1994, NIMH neurosci. cent., clinical brain
disorders branch, Washington DC - Patterns of cortical activity in
schizophreniaSchroeder et al Psychol Med. 1994
Nov24(4)947-55.