Task 8: Altered states of consciousness Flashcards
Altered states of consciousness (ASC):
include drug-induced states, hypnosis, mental illness and mindfulness
How to define altered states of consciousness
a)OBJECTIVELY – define ASC in terms of how it was induced
Problem: how do we know whether two slightly different drugs produce the same or different ASCs? How can we measure similarity? What about dosage?
b) PHYSIOLOGICALLY AND BEHAVIORALLY – heart rate, cortical oxygen consumption, ability to walk in a straight line, expressions of emotions, etc.
Problem: very small changes in physiology may be associated with large changes in subjective state and vice versa.
c) SUBJECTIVELY – most common strategy. ACT it the qualitative alteration in the overall pattern of mental functioning, such that the experiencer feels his consciousness is radically different from the way it functions ordinarily.
Problem: what is normal? (people will always differ)
What is altered in an ASC?
a) Consciousness has changed – when we then would study what has altered, it should reveal what consciousness itself is
Problem: It is not possible to measure consciousness in isolation from changes in perception, memory and other cognitive-emotional functions
b) ASC compared to a normal state due to a change to mental function: all mental functions are involved – ASC cannot be fully understood without understanding changes to the whole system
3 major variables that often change during ASC
Attention: changes along 2 dimensions:
a) Direction: can be directed inwards and outwards
b) Focus: broad vs narrow
Memory: changes linked to effects on thinking and memory
Arousal: high vs. low
Mapping states of consciousness using a multidimensional space
PHENOMENAL STATE SPACE (C-space)a multidimensional space in which a persons current state is defined by hundreds of variables
TART- 2 dimensions: 1. irrationality 2. ability to hallucinate Out of that, 3 major clusters occur: 1. Dreaming 2. Lucid dreaming 3. Ordinary consciousness All other positions cannot be occupied or are unstable. The occupied areas are discrete states of consciousness. To move into another region, one has to cross a forbidden zone
STEVEN LAUREY: 2 dimensions:
1. level of arousal: physiological wakefulness
2. awareness of environmental self: content of consciousness - requires a functionally integrated cortex with its subcortical loops
Most states and contents are positively correlated you need to be awake in order to be aware
AIM model by Allan Hobson: 3 dimensions
a) activation energy - similar to arousal (EEG)
b) input source: external or internal sources of input
c) ratio of amines (high when awake) to choline (high during REM)
States can be positioned in the brain-mind space
4-D MODEL:
a)Activation (low to high arousal)
b)Awareness span (narrow vs. broad)
c)Self-awareness (diminished to heightened)
d)Sensory dynamics (reduced to heightened sensation)
First step towards constructing a C-space
B-space
the space of functional brain-states
Challenge: create a mapping btw c-space (the space of states of consciousness) and B-space
meditation
Maintained voluntary shifts if attention
Interpretations of meditation (what does it do?)
- Meditation ist more than sleep or dozing: EEG profiles show difference, yet many meditators take mini naps
- Meditators learn to hold themselves at the transitional level btw sleep and wakefulness
- Meditations induce altered states of consciousness: sometimes it is the goal to reach different ASC
- Stimulation of rewards system: flood of dopamine - increased noradrenaline and then endorphins - opioids fade. Shifts can be seen with EEG and fMRI - d-ASC: term says that we should look for recognizable isomorphism between phenomenology and physiology
- d-ASC expresses the discrete state of brain networks from baseline.Idea is to correlate specific d-ASCs with changes in brain activity
- gradual change of neural structure: states reached by novice meditators may overlap with normal functioning, but advanced may reach unique states (increased synchronization etc)..
Mental illness
Some kinds of mental illness can induce ACT:
1. Mental illness is never solely mental: all psychological disorders involve feedback loops between thought patterns, emotions and moods, behaviors and bodily states
- Factors sustaining mental illness is the difference btw nature of experience when ill and when healthy. This can make it hard to remember states of consciousness other then the pathological one
Is illness itself an ACT? ACT is temporary, not permanent (psychosis yes, schizophrenia no)
Theories of sleep and dreaming
Jung: dreams are meaningful reflection of unconscious processes whose psychic importance is equal to that of the conscious mind itself
Activation synthesis hypothesis: dreaming results from rapid-eye-movement (REM) sleep physiology.
More recent theories: dreams fulfill an adaptive function related to emotion-regulation, learning and memory consolidation. reactivate and consolidate novel and individually relevant experiences
- biological defense mechanism: stimulate threatening situations
REM sleep
-definition and lesions
global high-frequency and low amplitude EEG activity, increased heart rate, respiratory activity, and muscle atonia - vivid dreams Lesions: a) forebrain: REM sleep without dreams b) Hindbrain: dreams without REM sleep
REM SLEEP phenomenological characteristics
NARRATIVE: Loose, bizarre narratives, related to current concerns, reflect interest, personality, and mood
- Dreamer is often uncertain about time, space and personal identities but has the subjective experience of being awake
SENSATION AND PERCEPTION: DREAMS share similarities with experiences during wakefulness:
- Visual and auditory sensations, physical activities, and language
- Tactile percepts, odors and tastes, as well as pleasure and pain are less commonly reported
Alterations from waking experiences: sensory distortions, misidentifications of characters and places, changes in the integration of time and location…
Emotions: most emotional content in that dreams (some emotions are more displayed than others)
Consciousness during REM
Dreams that occur during REM sleep show mostly aspects of primary but not secondary consciousness.
- Less metacognitive activity, reflective thoughts and volitional capabilities
Brain activity during REM
Large similarities with wakefulness
HYPERACTIVITY:Several brain regions become particular active during REM:
- Higher-order occipitotemporal visual association areas – vivid dreaming
- Motor regions, cerebellum, basal ganglia – motor content
- Pontine tegmentum, thalamus, basal forebrain, limbic and paralimbic structures – emotional processing
- Medial PFC, medial temporal lobe region, posterior cingulate cortex – memory and self-referential processing
- Default mode network
HYPOACTIVITY: Less active regions during REM sleep
- Right inferior parietal cortex – waking volition. Might allow the dreamer to participate in both first and third-person perspectives
- Executive regions – lack of insight, restricted volitional capacities, impaired metacognition
NREM SLEEP
Divided into three different stages (N1, N2, N3).
It is characterized by a global low-frequency and high amplitude EEG activity, slow and regular breathing and heart rate, as well as low blood pressure
Awakening from NREM yielded reports of dreaming as well (80-90%), but reports tend to be shorter.
- Sleep inertia – grogginess following abrupt awakening makes the evaluation of theses reports difficult
- dreams are often only recall of REM dreams or confabulations
BUT dreams also have been reported before occurrence of REM
Wakefulness, REM and NREM sleep are not necessarily mutually exclusive phenomena. Dreaming might be described along a continuum.
Phenomenological characteristics NREM
During sleep-onset, people often experience hypnagogic hallucinations while being unaware that they have already fallen asleep.
Similarities with REM sleep dreams: bizarreness
Differences “: emotional flatness, static, no self-character. Activities that were performed before sleeping might influence the content of such hallucinations
Change in consciousness in NREM sleep
Reports of conscious experience across NREM sleep phases vary, but they prove that consciousness doesn’t fully cease
Brain activity NREM
Visual imagery during sleep onset is represented by brain regions including the early visual pathway, fusiform face area, parahippocampal place area
- high frequency in parietal occipital area during dreaming
Lucid dreaming
Occurs typically during late night REM sleep
- may also occur during NREM
- achieved though metacognitive training, external sensory stimulation and through frequently contemplating about one’s own state of consciousness
Change in level of consciousness during lucid dreaming
A hybrid state of consciousness with features of both waking and dreaming
Volitional aspects vary across wakefulness, non-lucid and lucid dreaming:
1. Self-determination – similar for lucid dreaming and wakefulness
- Planning – impaired during non-lucid and lucid dreaming
- Intention enactment – more pronounced during lucid dreaming and did not differ between wakefulness and non-lucid dreaming
Contrasting lucid and non-lucid dreaming mirrors contrasting primary and secondary consciousness. Non-lucid REM dreams lack features of secondary consciousness
brain activity during lucid dreaming
Increased activity: DLPFC, bilateral frontopolar prefrontal cortex, parietal areas, inferior parietal lobules, supramarginal gyrus
important for reflective capabilities (secondary consciousness)
Dreaming and similarities with psychosis
The 2 have often been compared (false beliefs, distorted perception etc).-
- elevated levels and uncritical acceptance of cognitive bizarreness
- decreased reality testing
Supported by fMRI: data of psychotic patients= dream bizarreness= waking experience of patients
THERE ARE SOME SHARED MECHANISMS OF DREAMING AND PSYCHOSIS
Primary consciousness
general notion of sensory awareness
Secondary consciousness
reflection and high level awareness
Our psyche has 2 sides
a) Diurnal side – consciousness
b) Nocturnal side: unconscious psychic activity which we apprehend as dreamlike fantasy
Dreams are fragments of involuntary psychic activity, just conscious enough to be reproducible in the waking state.
neural correlates of dream phenomenology and changes in consciousness:
CONSCIOUSNESS: Decreased activity in the DLPFC during REM sleep might be responsible for features of secondary consciousness (active in lucid dreaming)
- Dreamer beliefs that he is awake, maybe due to persistent inactivation of frontal and parietal circuits
Global deactivation of the pontine tegmentum, amygdala, anterior commissure, parietal operculum during NREM sleep and their reactivation during REM sleep might explain why some aspects of consciousness during REM sleep are more readily available than during NREM sleep
Phenomenology in dreams
There are common neural substrates for perception and imagery.
- Some of the visual experiences during sleep onset are represented by brain activity similar to the ones observed during stimulus perception.
- Patients with extrastriate occipito-temporal lesion report cessation of visual dream imagery
- Dream hand movements activate the same motor area active during actual movements
- Waking emotional processes active during REM sleep are inhibited during NREM sleep
Problems with dream research
- Much remains to be learned about mechanisms underlying NREM sleep.
- Causal links have not receive much attention yet
- No objective assessments of dreams is currently possible, so one has to rely on dream reports
Novel brain imagery may enable more objective readout of the dream:
I. Memory is reconstructive and there is a time lag between the actual dream and its report
II.Actual dream content may be distorted due to interfering material of waking environment
III.Limitation to verbal report
IV.Moral censorship - Most researchers are working in highly specialized fields only
- examine for whom dream lucidity training might be a good treatment
Ayahuasca study
Ayahuasca: hallucinogenic beverage: decoction of root bark & stem cortex of the liana + DMT
SET AND SETTING HYPOTHESIS: psychological effect depend on set (emotional state) and setting (physical environment)
PROCESS:
2 groups:
1. Santo Daime: ritual is a collective performance of human hymns, dance and music- all PP are required to sing and dance and it lasts for 12 hours
- UDV: preaching occurs though questions directed to preacher by pp, sometimes silence, pp remain seated and it takes only 4 h
RESULTS: Use of Ayahuasca leads to an ASC.
- experience of receiving cognition and feelings from the outside is independent of set and setting (radical Cogn alterations occur anyways)
- peaceful states were more experienced by UDV
EMOTIONAL AND BEHAVIORAL IMPROVEMENT WAS BASED ON:
- subjects wish for change in their relationship
- emotional + perceptual excitement experienced in nature would satisfy the desire to transcend every day life
- suggestibility to acceptance of morally and optimistically laden ritual contents during ASC would also be extended to the following days
Broadcasting theory of consciousness
Access consciousness: things are only conscious if they are available for all modules in the brain
- masking used to test that
Activation of Heschl’s gyrus during auditory hallucination:
Present schizophrenic patients with voice/tones and ask them to click on a button whenever they hear something.
- when nothing was played, patients still pressed the button from time to time activity in Heschl’s gyrus (CONSCIOUSNESS STARTS THERE)
Multiscale organization in the brain:
Dehaene: if we study the brain long and detailed enough, Chalmers hard problem will disappear
- qualia can be scientifically understood
Content specific NCC:
the subjective experience humans are in at any given moment of time
SEARCH FOR CONTENT SPECIFIC NCC:
1. Mapping steps – receptive fields of recording sites are determined: this neuron is doing this
2. Ambiguous stimuli – Expose subjects to ambiguous stimuli: physical stimulation is constant but consciousness perception alters between stages
Study motion quartet:
2 moving blocks that can be seen as both moving horizontally and vertically
It was possible to link different perceptions to different activities in V5 (proves involvement of horizontal and vertical columns in conscious perception)
- Chalmers no longer holds: he said that its not possible to find NCC
Study: reading out images from the minds eye
Decoding: reconstructing the stimulus that had activated a brain area (stimulus can be internal or external)
Participants were shown letters
-letters were seen by decoding brain activity
Study: enable blinds people to see:
People who became blind during their life still have an intact visual context map. Use of electrodes that map an image on the visual cortex (camera records the environment)
Neurofeedback, meditation & self-therapy:
Monk received neurofeedback while meditating
- ventral striatum was modulated by the intensity of positive mental states (rewards centter)
Same was done with people who could not meditate- only some could do
Depressed patients could learn to upregulate their brain activation within the emotion network. (decreased symptoms by 1/3)
Control system (brain areas):
Posterior parietal: attention controller
Thalamus: arousal
DPFC: goal processor
