Lecture 23 - Altered States of Consciousness Flashcards
Do negative side effects of psychadelics come from the “drug experience” as opposed to the drug having a toxic effect?
Yes.
What is one of the known ways that hallucinogens, such as LSD, psylocybin, mescaline, DMT, act in the brain?
These chemical compounds (or rather their active part) all have similar structures to serotonin and are known to act on serotonin receptors across the brain.
What is the corticothalamic loop understanding of how hallucinogens cause halluncinations or the altered states of consciousness that they are known to cause?
They bind to serotonin receptors on the neurons in level 5 of the cortex, causing them to fire.
These neruons feed into and are connected to the thalamus. Increased firing of these neurons increases activation of neurons in the thalamus. Increased activation of these neurons leads to increased activation of other areas of the brain that the thalamus sends information to.
The binding of these compounds to the serotonin receptors can also lead to decreased activation/inhibition of neurons and connections between cortex and thalamus.
This could explain why people can experience changes in visual and auditory perception.
What areas have their connectivity increased when taking hallucinogens?
Sensory areas and thalamus have increased connectivity.
What areas have their connectivity decreased when taking hallucinogens?
Executive control networks and thalamus have decreased connectivity.
When people take classic psychedlics, are their experiences completely random?
No. Whilst people have unique experiences in many ways, there are common qualities to these experiences, as well as common phenomena experienced, such as visual distortions or a sense of unity and spiritual connectedness.
What are some of the changes to perception people who take psychedics experience?
Decreased sensory inhibition. People are more likely to not get backward masking.
Feel that colours are brighter and more varied, however, they cannot actually visually disciminate colours better.
What are some of the changes to cognition experienced by those who have taken psychedelics?
Conflicts and contradictions seem to dissolve.
Speech production and language complexity (including speaking non-mothertongue language) are decreased.
Cognitive control seems to decrease.
What are some of the changes seen in people’s sense of unity, self, and time when on psychedelics?
People tend to experience a sense of ‘oneness’.
Experiences of past, present, and future.
What are three dimensions of consciousness that Olivia Carter explored when looking at the effect of psychedelics on consciousness?
Perception - psychedlics appear to increase perception.
Cognition - psychedelics appear to decrease cognition.
Unity - psychedlics appear to increase sense of unity and change our perception and access to to time. Uncertain as to whether this is an improvement in consciousness or not.
What are some of the methodological obstacles to studying meditation?
Many types of meditation.
There are potentially many types of placebo effects happening, such as a sense being part of a group or doing something helpful. This makes it difficult to identify what is actually happening during meditation that elicits the positive effects.
What are some of the areas activated during meditation?
Insula.
Cingualte cortex.
Amygdala.
