Transcript Slide 1

States of consciousness
Prof. dr. Anton M.L. Coenen
NICI – Department of Biological Psychology
Radboud University Nijmegen
The Netherlands
[email protected]
States of consciousness
• Lecture 3. Enigmatic states of
consciousness: REM sleep and dreaming
24
hours
16
REM sleep
10
Non-REM
0
Conception
Birth
1
Age in years
10
20
Baby
Adult
Eugene Aserinsky and Nathaniel Kleitman
(1921-1998)
(1895-1999)
From left to right, Michel Jouvet, William Dement, Nathaniel Kleitman and Eugene
Aserinsky, after their symposium on the discovery of REM sleep on June 1, 1995.
The symposium commemorated the 100th birthday of Nathaniel Kleitman in April of
1995.
After Glenn and Steriade, 1982
After Hirsch et al, 1983
(after Morrison, 1983)
Kekulé’s dream
One famous dream – of the Frenchman Alfred Maury –
seems to show that dreams are almost instantaneous.
He saw himself, a victim of the Franch Revolution,
being tried and sent to the guillotine.
He felt the knife fall – and then awoke to find the bedrail had fallen on his neck.
Sigmund Freud is shown here with his daughter Anna,
who herself became an influential psychoanalytic theorist.
After Fischer et al, 1965.
Diagram of the spinal control of penile erections (After Hirshkowitz and
Schmidt, 2005)
Brain areas, lateral part of frontal cortex and medial part of parietal cortex,
that are less active during REM-sleep than during wakefulness (in red).
The cerebral Blood flow in the medial prefrontal is similar during wakefulness
and REM sleep and is decreased during SWS (after Maquet et al, 2005)
COGNITIVE THEORY
ON DREAMING AND REM-SLEEP
INFORMATION PROCESSING:
SELECTION OF RELEVANT INFORMATION
FOR CONSOLIDATION
IN LONG TERM MEMORY
After Jenkins and
Dallenbach, 1924
THE POSITIVE EFFECT OF
SLEEP ON MEMORY
THE INTERFERENCE HYPOTHESIS
THE REM-SLEEP HYPOTHESIS
THE SEQUENTIAL HYPOTHESIS
THE SLOW-WAVE SLEEP HYPOTHESIS
Cortical activation (W and REMS) and slow wave promoting (SWS) systems. The
excitatory pathway of the arousal system emerges from the brainstem RF to ascend
along a dorsal trajectory into the thalamus upon the non-specific thalamo-cortical
projection system and a ventral trajectory through lateral hypothalamus up to the basal
forebrain, with widespread projections to the cerebral cortex.
Neurons containing GABA, also located in the basal forebrain, give rise to inhibitory
cortical projections. They discharge maximally with slow waves and minimally with fast
waves. (after Jones, 2002)
• REM-sleep is an active state of the brain, periodically
occurring during slow wave sleep
• During REM-sleep specific parts of the brain are
activated, such as the limbic system, and the visual and
motor cortical areas. The pons is the generator of REMsleep. The prefrontal lobe is de-activated.
• REM-sleep is highly associated with dreaming, but, it is
not clear whether REM-sleep serves an own (unknown)
function (activation-synthesis hypothesis, cognitive
theories) or that it serves to generate dreams with its
own function (psychoanalytic theories).
•REM-sleep, in association with dreaming, must be
regarded as a third, natural occurring state of
consciousness.