By: Philip Gerrans and Chris Letheby
In: Aeon
Date: 2018
Key Concepts:
- Psychedelics:
- Induce an altered state of consciousness known as ‘ego dissolution’.
- Sensations of self-transcendence.
- A feeling in which the mind is put in touch more directly and intensely with the world.
- Producing a profound sense of connection and boundlessness.
- Bind to a specific type of serotonin receptor in the brain.
- The 5-HT2A receptor.
- Precipitates a complex cascade of electrochemical signaling.
- Induce an altered state of consciousness known as ‘ego dissolution’.
- Complex relationship between the brain, the self and its world.
- Where does the subjective experience of being a person come from?
- How is it related to the brute matter that we’re made of?
- Views on consciousness / conscious experience:
- Awareness of a ‘thinking thing’, the self.
- Self-awareness is a form of bodily awareness.
- Produced (at least in part) by interoception.
- Ability to monitor and detect autonomic and visceral processes.
- A mere stream of experiences.
- We incorrectly infer the existence of an underlying entity from this flow of experiential moments.
- We have perceptual, cognitive, sensory and, bodily experiences – but that is all.
- Abnormal cognitive conditions, pathological or otherwise, serve as a crucial source of evidence.
- They offer the chance to look at the self when it is not working ‘properly’.
- Awareness of a ‘thinking thing’, the self.
- Cognitive binding.
- The integration of representational parts into representational wholes by the brain.
- Unclear how – the “binding problem” remains unsolved.
- Predictive processing.
- Theory of cognition.
- Views the brain as a prediction machine.
- Models the causal structure of the world to anticipate future inputs.
- Any discrepancies between an expectation and an input take = error signal.
- Demands a response from the organism:
- Update the internal model.
- Or, act to reduce the unpredicted input.
- Humans build such accurate predictive models of their world that error signals are minimised, almost to the point of being eliminated.
- Model.
- Mental representations that organize information.
- Allow the brain to extract signals from noise.
- What we ultimately experience, is the model that we’ve learned is the best fit for the information to hand, that best predicts and accounts for our perceptions before they happen.
- Perception becomes little more than a kind of controlled hallucination.
- There is some kind of world out there that our brains need to find a way to track.
- It is by approximating the structure of this reality (even if we can’t apprehend its metaphysical truth or nature) that our predictive brains save us from getting run over.
- We do not experience the external world directly, but via our mind’s best guess as to what is going on out there.
- Takes advantage of regularities in the environment.
- Due to statistical regularities in the environment over time, the most predictively successful perceptual models turn out to be those that create a world and populate it with objects with particular properties, concrete and abstract, to be sensed and thought about.
- Past experience teaches us that certain combinations of features are more likely to co-occur than others.
- This predicted coherence is increased by attributing these features to the same persisting object.
- Your sense of self is nothing more than one of these rough-and-ready models.
- Compressing properties of the world so that they’re easier to grasp.
- The modeled self is a sort of meta-filter for the signals you get from the functioning of your whole organism.
- A hierarchy of models.
- Each level deals with different aspects of organismic functioning.
- Bodily boundaries, regulating homeostasis and sensory-motor encounters with the world.
- Memory, inference and imagination.
- Narrative “I”, bound across hierarchy and through time.
- Each level deals with different aspects of organismic functioning.
- Located in salience network and default mode network.
- Salience network:
- The significance of bodily states triggered by worldly encounters.
- More or less: embodied self.
- Default mode network:
- Episodes of autobiographical thought such as memory, imagination, planning and decision-making.
- More or less: narrative self.
- Salience network:
- Predictions can cause stress and unhappiness.
- Self-models can magnify the adversity of the social world.
- Predictions can become self-fulfilling.
- Analogy: lenses of our eyes.
- Psychedelics and ego dissolution.
- The integrity of the self-model degrades.
- We no longer take it for granted that our experience must be interpreted by that model.
- Psychedelics allow you briefly to hear your personal language of subjectivity as sound, not meaning.
- Whether you want to learn another language of selfhood is up to you.
- Self:
- A model, not a thing.
- Forms over a life time.
- A fundamental cognitive strategy, one which has developed over evolutionary time.
- [Associated with material representations, such as strengthened neural connections?]