Chapter 6, The Hidden Spring, The source Flashcards
What is the basic assumption of neuropsychology and why does that invalidate the notion that the cortex is the seat of consciousness?
The basic assumption of neuropsychology is that if a lesion occurs in a particular brain region, then that regions function is lost. However, if lesions occur in the cortex, then how can someone retain consciousness? This understanding invalidates that assumption
What is the name of the core structure in the brainstem where consciousness arises, according to both solms and Panksepp?
The reticular activating system in the brainstem. This is what Solms refers to when he says the hidden spring
Why is the reticular core system a site that Solms believes is the hidden spring of consciousness?
Because in it are the sources of neurotransmitters that govern our consciousness. Dopamine, serotonin, and norepinephrine neurons are located in this dense bundle and these sites are the target to much psychopharmacology, whose intent is to alter consciousness to a more favorable state.
If the RAS in the brain stem is the site of consciousness, what must it also be the original site for?
Affect
Since affect and consciousness originate from the same place, what does that imply about feelings?
Feelings are the primary source of consciousness, and without access/understanding to them people become separated from reality
What does Solms believe is the most accurate way to describe the level of activity within the RAS?
Arousal. The level of arousal will indicate how activated the RAS is
What wave pattern is most correlated with consciousness? Describe the wave pattern and its hz
Gamma wave patternsLow wave patterns with higher amplitudes (25-100hz)
What does the cortex’s level of consciousness depend on?
The level of activation in the brain stem
What is the least arousing wave pattern seen in cortical activity?
The delta wave pattern, at a frequency of 2hz. This may be a good sound to get into to turn down arousal, especially prior to something like sleep
Briefly describe the notion of synaptic transmission
The way neurons within a circuit communicate to each other is through synaptic transmission. This communication between synapses is facilitatedthrough either excitatory or inhibitory neurotransmitters. If an abundance of neurotransmitters exists, then those molecules will continue to be passed down to other neurons in the circuit, or they will be taken back into the presynaptic neuron (uptake)
Neurons in circuit–> Neurotransmitters (inhibitory or excitatory)–> Continued transmission or reuptake
What is the other form of synaptic transmission that takes place? Briefly describe how it works
Post synaptic modulation. It arises endogenously in the reticular activating system and has everything do with arousal
Who are the central players in post synaptic modulation and how do they govern activity in the brain?
The central players are neuromodulators and they act on whole regions of the brain, rather than through individual synapses. Because they don’t operate through specific channels, and influence whole networks, they end up regulating the whole state of the cortex. This influences experience according to the state one is in.
Ex- If someone is approaching a stranger, their response to them will change according to state the cortex has been put in through neuromodulation. If they are in a seeking state they may strike up a conversation, if in fear they will hope to avoid
What is the difference between channel and state and how can that help you understand the different ways in which neurons communicate with one another?
The state of the cortex alters the strength of the message passing between channels. The state governs how loudly the channels communicate with one another.
How does arousal (state) influence synaptic transmission (channel)?
Arousal will govern which synaptic impulses will be transmitted, and the strength to which they will
How do neuromodulators vary in their function, relative to neurotransmitters?
How do neuromodulators exert greater influence on neuroplasticity than neurotransmitters?
Neuromodulators are slow acting and longer lasting, because the chemicals last longer and therefore continuously influence the frequency of firing of nerve channels. Neuromodulators are also not as binary and neurotransmitters.
Since neuromodulators last for longer periods of time, the network they act in will stay boosted until the neuromodulators down modulate, therefore contributing to extended neuroplasticity between channels during that time.
Where do neuromodulators come from in the body? In the brain?
Body- pituitary, adrenals, thyroid, sex glands
Brain- Hypothalamus, RAS (the brains central source of arousal)
What are the 5 main neuromodulators responsible for arousal that originate in the reticular brain stem and where do they release from?
Dopamine- ventral tegmental area and substantial nigra
Noradrenaline- locus coreleus
Acetylcholine- mesopontine tegmentum and basal forebrain nuclei
Histamine- tuberomamillary hypothalamus
Serotonin- Raphe nuclei
Neuromodulators can only affect cells if they contain what?
Receptors or receptor subtypes
Can neuromodulators create states on their own?
No, they can only modulate signals that already exist. If a circuit is active already, the neuromodulation will either enhance its existing function or inhibit it
To review, where does arousal originate from and how does it arise physiologically?
Arousal originates primarily in the brain stem and hypothalamus and arouses the forebrain through modulating neurotransmission
Where is the site in the brain where all the affective circuits converge? Where is it located and what does it’s integrity indicate?
The periacqueductal grey. It’s integrity is what governs the shifting from vegetative wakefulness to affective arousal. It’s location is a set of tightly packed neurons in the midbrain
What lies at the basis of conscious behavior, and what does Solms believe is not an accurate description of consciousness?
Arousal governs ones intentionality, which forms the basis of conscious behavior. SOlms believe wakefulness is not an accurate description of consciousness, as one can be vegetatively awake
How do the RAS and PAG differ in the direction of information they send to the forebrain?
The RAS sends information upwards into the cortex, while the PAG receives downward communication from the cortex.
RAS—> Forebrain—> PAG
What role does the PAG play in survival, and how does it receive its information to guide behavior?
The PAG orchestrates coping behaviors in response to threatened survival by integrating afferent information from the periphery and higher thinking centers.
It’s as if the subcortical information communicated to the cortex what is happening to someone and whether their survival is threatened, and if so, the cortex communicates to the PAG the threat, and the PAG organizes the survival response.
THE PAG IS THE BRAINS MAIN OUTPUT FOR FEELINGS AND EMOTIONAL BEHAVIORS
The PAG forms 2 columns along the canal of the brainstem. What is each column responsible for when it comes to coping strategies and what emotional circuits terminate in these areas?
Anterior column- Active defense coping strategies. Fight/flight response. The fear, rage and panic circuits terminate here
Posterior column-Passive defense coping strategies. Freeze response. Lust, seeking and care circuits terminate here
Once the affective circuitry terminates at the PAG, what must it now do with the incoming information?
It’s must evaluate what is most biologically imperative for survival, and then enact an action plan moving forward.
In any circumstances, the cortex will produce a cognitive strategy and then send it down to the midbrain in order to enact forward. How the does PAG inspire action to be taken?
By generating an affect that will determine and modulate the next sequence.
What structures works alongside the PAG in order to form the “midbrain decision triangle”?
What’s the role of the superior colliculus?
The superior colliculus and midbrain locomotor region.
It’s role is to provide an exteroceptive map that it builds according to the body’s senses.
Through the SC exteroceptive map, the bodies objective state becomes known, and this combines with the PAG’s subjective interpretation of what is happening in order to produce behavior.
The midbrain decision triangle governs what actions one takes by integrating affective, sensory and motor information. What criteria does it evaluate before making a decision?
It makes its decision according to what its currents needs are, and what opportunities to meet those needs exist
What roles do the superior colliculi and cortex play in producing an action sequence?
The superior colliculi provides the sensory motor mapping of potential targets and actions, and the cortex provides the detailed representations of the actions as they unfold. It’s like the superior colliculi does the planning and the cortex helps adjusts for errors that could happen.
The midbrain decision triangle enacts an action and then evaluates the response to that action. What is the response to the outcome of that action and how does that shape future prediction?
Once feedback is received on the consequences of an action, a feed forward model activates and expectations are now set for what this action will entail in the future. This is now the expectation of what will occur each time that action is taken.
When does conscious voluntary behavior become a part of one’s action sequence and what feedback allows someone to understand whether the action met the intended result?
When one doesn’t receive the expected feedback from the formed model in their mind and they must now adjust for errors.
The feedback coming in is affective and perceptual, and this information informs the individual of the consequences of that action.
Why does the brain use long term memory to predict outcomes of actions before they occur?
What is a structural example in the brain of this phenomenon?
When encountering new stimuli, how does the brain interpret the circumstance relative to encountering new or old information?
It’s an energy conservation strategy and reduces metabolic cost .
A structural example can be seen in that neurons signal more information from memory systems to external sense organs, than vice versa. That means memory history is influencing perception of events more than the actual events themselves.
The brain allows in those things that don’t match its prediction, in order to better update its prediction and have a set memory for that event so it can better manage it in the future. Old stimuli are given less emphasis, while new information is what is added to the prediction model.
What does SOlms believe the relationship is between affect and perception/cognition and action?
Solms believes perception/cognition/action are meant to contextualize affect, in order to create action while also updating memory systems to better predict for the future.
The brain’s internal model is to predict expectations of what’s to come, even though it may not always be accurate. What are 2 aspects of the expected content that are coded into the brains internal model?
The content of our predictions, and the likely hood of those predictions coming to. Both are coded into the brain to produce greater prediction and certainty
In regards to prediction of an event, does the content of the event or the level of confidence that that event will occur contribute to the level of arousal moderated by the RAS.
The level of confidence regarding an event will tune one’s level of arousal through neuromodulation.
What structures in the brain adjust the signal strength of expectations and describe the interaction between brain regions.
The expectation of an event yields a certain level of arousal, which is determined by the mid brain’s decision triangle. The MBDT sets the output and intensity of signaling from the RAS which is meant to communicate to the forebrain the expected events.
The stronger the arousal, the more one will be able to learn from experience, therefore contributing to better predictive modeling in the long term memory networks.
What is the relationship between prediction and arousal?
Prediction and outcome modulate arousal in order for learning to effectively occur, therefore preventing user errors from happening in future yet similar contexts
