Lecture 12 - Consciousness Flashcards
Why do we need consciousness?
In order to be able to process the world around us and the co-ordination of the body in external space
What are the two streams of consciousness?
Dorsal Path - Spatial Recognition
Ventral Path - Object Recognition
Where are ‘where?’ questions processed?
In the parietal cortex
Where are ‘when’ questions processed?
In the frontal region
Where are ‘what’ questions processed?
In the ventral path
Where are ‘how’ questions processed
In the frontal region
What is consciousness?
Observation of the internal mental representation
Outline the process of conscious perception
Visual stimulus –> Primary Processing –> Directing Attention –> Conscious Perception
What are the three main features which can be used to test cognitive abilities of comatose patients?
N100 - Primary processing
N200 - Attention
P300 - Memory functions
How strong is the p300 in comatose patients?
Very weak/ non-existent
Describe the word-matching test used to check cognitive abilities in comatose patients
Testing the N400 - which is the difference between words that match and words that don’t
The N400 is barely existent in comatose patients
Outline the semantic oddball test
Tests the N100 and P500
When words don’t fit in the sentence
Some comatose patients still had a significant P500/N100
How does N100 vary with comatization?
It is intact at high levels until non-responsive, pathological EEG
How does P300 vary with comatisation severity?
Decreases rapidly as consciousness decreases
How does the N400 vary with the severity of comatisation?
It is not even reliably detected in healthy controls
How is coma state detected?
Using the N100, p300 and N400 from EEGs
What are the states of consciousness?
Wakeful Vigilance - Resting, Concentration Somnolence/Drowsiness Sleep Dream Meditation Hypnotic Ecstatic
What are the different rhythms?
Delta - 1-4 Hz Theta - 4-8Hz Alpha - 8-12 Hz Beta - 15 - 30Hz Gamma - 30-40 Hz
What brain area controls the sleep/wake cycle?
Reticular formation
What function does melatonin have?
It is secreted by the pineal gland and regu;ates the sleep wake cycle
During sleep what happens
Energy consumption reduced
Body rhythms slow doen
What are the two main types of sleep?
REM Sleep
Non-REM Sleep
What are the stages of non-REM sleep?
Stage 1 - Somnolence, drowsiness, theta waves
Stage 2 - 50% of sleep, theta waves, with sleep spindles and K complexes
Stage 3 - Slow wave sleep, delta waves
What are the possible pathologies associated with consciousness alterations?
Dementia - narrowing of consciousness
Psychosis -Disturbance of contents
Comatose States- reduction of consciousness
What is a waking coma?
Where there are signs of sleep wake cycles
What does the Glasgow Coma scale measure?
Eye opening, verbal communications and motor reactions
What are the two aspects of the mental realm?
Wakefulness - Objective
Conscious Awareness - subjective
What is wakefulness?
Attentiveness, readiness of the organism to react critically to events
What is conscious awareness?
Subjective experience of mental functions, vividness of this experience can serve as a measure for consciousness
What is lucid dreaming?
When the dreamer is fully conscious, can voluntarily act, knows they are dreaming and knows about their own personality. these can often be more vivid than real life
What do lucid dreams show?
The autonomy of stable mental representations
What are the soft problems of consciousness?
The ability to discriminate, categorize and react to stimuli
the integration of information by the cognitive system
the reportability of mental states
the ability of a system to access it’s own internal states
the focus of attention
the deliberate control of behaviour
the difference between wakefulness and sleep
What are the hard problesm of consciousness?
Problem of experience
Who is the observor?
Who is the observor and is there a self?
Have to distinguish between the concept of self
Qualia phenomenon emerging from the perspective of being inside
Is the observor emerging from neuronal function?
the mere presence of an observor can affect the outcome in quantum physics
Outline the hierarchy of consciousness related functions
Instinct (proto-self) Prerational (core-consciousness) Recognizing-conceptual Rational-logical Multi-perspective
What are perceptrons?
They are a simple model of a neuron developed by Rosenball. they create a feedforward network, with weighted connections.
Input, input layer, output layer, target output
What disproves the perceptron theory?
Supervised learning via back propagation
Presentation of a pattern –> calculation of an output –> comparison with target –> correction of weights –> presentation of a pattern
Isn’t a simple feed forward network
What is the hopfield network?
A type of recurrent artificial neural network popularized by John Hopfield in 1982. Hopfield nets serve as content-addressable memory systems with binary threshold nodes.
All neurons are connected to all other neurons in a certain way
What are attractor states?
Hidden configurations within the hopfield network pattern, which can only be seen when we stimulate it
What can the hopfield network explain?
Self organisation in the brain
operant conditioning
Neuronal plasticity
Hebbs rule -neurons that fire together wire together
Assoicaitve behaviours
Holographic brain model - destructing a part of the network does not destroy all or single memories
In the hopfield network how many neurons are needed to store one image?
10
What’s the Orchestrated Object reduction (Orch OR) model?
Microtubules are structured molecules within neurons, within these structures huge amounts of information can be stored
What’s the Casimir effect?
Zero point fluctuations cause a force between plates and thus act on matter i.e. empty space has energies which appear and disappear
Outline the hierarchy of consciousness related functions
A-categorical - ability to abstain from well automized functions
Transrational - relativity of concepts and logic
Multiperspective - Empathic
Rational-logical - associations and combinations of concepts
Recognizing-conceptual - categories and concepts, feelings
Prerational - emotions, neuronal representation
Instinct
What functions are necessary for being conscious?
Complex interactions of neuronal activites
1 hemispher is enough
Requires no active behaviour
Requires no emotions
Does not require language or self consciousness
What are the functions of consciousness associated with sitting in silence?
Reduction of the stimulus response mechanism
What are the functions of consciousness associated with simplicity, elementariness
No complex cognitive processes
What are the functions of consciousness associated with mindful presence?
No creation of time
What are the functions of consciousness associated with nonduality, no self, no seperation
No subject-object relationship
What effects can meditation have?
Can alter emotional regulation, attention regulation, perspective change on self and self/body awareness. It also structurally effects the hippocampus, anguilim and cerebellum
