++AMYGDALA

AMYGDALA:

++ has “…an important role in determining whether a certain situation carried a positive approach or a negative avoidance value for the organism.  (Henry/np/40)”

++  importance of flight or flight mechanism intimately connected with the amygdala

++ linked to the locus ceruleus

++++++++++++++++++++++

++++++++++++++++++++

“A fearful stimulus primes the body with adrenaline and prompts the fastest physical reaction possible. When the brain is triggered in fear, the autonomic system and stress hormones are activated.  The amygdala gets immediate input from the thalamus and acts to start up the internal readiness and reaction system.

This bypasses the cortex and any consideration of the context and suchit is just responding.

In fact, the feared stimulus and the programmed response to it are indelibly etched into the amygdala, as its job is to alert the animal to dangerous, novel, and interesting situations and to direct its response.  (Ratey/ug/232)”

++++++++++++++++++++++

“Both the right and the left frontal lobes are very important for the regulation of emotion, needed for making decisions in the social and personal realm.  It may be that this area connects the limbic system and the motor cortex, establishing the link between areas that plan and those that carry out the actions.  There may even be an “upper” path between the limbic system and the cortex through the cingulate gyrus that deals with pleasure and sociability and a “lower” path involving the amygdala and ventromedial prefrontal cortex that deals with issues of self-preservation.  (Ratey/ug/230)”

++++

Activation, whether by fear or arousal, causes an outpouring of activity toward the motor cortex to initiate and guide a movement response.  At the same time,

there are messages from the aroused limbic area to other areas of the cortex to evaluate the incoming data.

After a decision is made, guidance is sent from the cortex back to the amygdala to tell it to act, to cool off [brakes are applied], or that it is not advisable to act.  (Ratey/ug/228)”  cc files

++++

“The limbic system comprises the amygdala, hippocampus, medial thalamus, nucleus accumbens, and basal forebrain, all of which connect to the anterior cingulate gyrus, which is the major gateway to the frontal cortex.  This system is the launching point of emotions and the emotional connector to the cognitive prefrontal cortex.  Yet all of it is wrapped around the system for movement.  (Ratey/ug/227)”

++++

amygdala removed in both hemispheres, “While not cognitively impaired at all, the woman has some deficits in recognizing emotions of all kinds and a complete lack of recognition of the emotions of fear and anger in people’s voices.  She understands what fear and anger are and when and how they (Ratey/ug/225) might be expressed, but she cannot comprehend fear or anger as they are manifested in real life.  Imagine how your life would be if you could not understand that someone was angry with you or that you were angry with them.  Imagine the danger if you could not understand the urgency in a command like “Look out for the bus!”  (Ratey/ug/226)”

++++

information about emotion stimulus enters brain through  thalamus, from there follows one of two pathways:

to the cerebral cortex for cognitive assessment

or to the amygdala and the hypothalamus, which direct body reactions (Ratey/ug/225)  cc to files

++++

Input from a person’s face that will lead to identification is channeled via different pathways from the information about the emotional expression on the person’s face.  (Ratey/ug/227)”

“The emotional information goes directly to the amygdala and the insula, which then send directions to act to our motor systems in the brain.  So there is a splitting of the information, and you can identify a face and have no emotional confirmation about it and claim that the person is an imposter, which happens in Capgras’s syndrome.  (Ratey/ug/227)”

++++

“A number of structural and functional neurobiological consequences of early stressful experience have been identified and include reduced corpus callosum size, attenuated [thinned, weakened] development of the left neocortex, hippocampus, and amygdala, enhanced electrical irritability in limbic structures, and reduced functional activity of the cerebellar vermis.  (Teicher/nc/2003)” cc to files on these brain areas

The neurobiological consequences of early stress and childhood maltreatment.

Neuroscience and Biobehavioral Reviews 27 (2003) 33-44

Martin H. Teicher, Susan L. Andersen, Ann Polcari, Carl M. Anderson, Carryl P. Navalta, Dennis M. Kim

+++++

from Teicher/nc

“The amygdaloid nuclei are among the most sensitive brain structures for the emergence of kindling [23].  Kindling is a process in which repeated intermittent neuronal stimulation produces greater and greater alteration in the excitability of those neurons, eventually resulting in spontaneous electrical discharges, or seizures [24, 25].  Kindling results in long-term alterations in neuronal excitability that can have a major impact on behavioral control [25].  Early stress produces an enduring alteration in the subunit composition of GAGA-A supramolecular complex in the amygdala [26], subsequently reducing the density of both central benzodiazepine receptors and high affinity GABA-A receptors [26,27].  In addition, stress results in increased dopamine levels and attenuated serotonin levels in the amygdala and nucleus accumbens [28-30]. (Teicher/nc/34)”

“Abnormal amygdala or hippocampal development, combined with a diminished density of central benzodiazepine and high affinity GABA-A receptors or alterations in subunit structure, may lead to the emergence of temporal lobe or limbic seizure-like activity [31-34], or ‘limbic irritability’.  We created the limbic system checklist-33 (LSCL-33) to rate the occurrence of symptoms that often emerge during temporal lobe seizures (e.g. perceptual distortions, brief hallucinatory events, motor automatisms,  (Teicher/nc/34) and dissociative phenomena), hypothesizing that the effect of stress on limbic structures may produce these symptoms in the absence of clinical seizures [35].  We found that adult outpatients with a self-reported history of physical or sexual abuse had increased LSCL-33 scores that were dramatically elevated in patients with a history of combined abuse, both physical and sexual [35].  Subsequently, we found that psychiatrically hospitalized children with a history of abuse had a two-fold increased incidence of clinically significant EEG abnormalities in the frontotemporal region, which consisted of spikes, sharp waves, or paroxysmal slowing, predominantly in the left hemisphere [36].  (Teicher/nc/35)”

amygdala volume shown not different in PTSD but about 8% less volume in BPD with childhood sexual abuse

“Because amygdala over-activation maybe [sic] a critical factor in PTSD [37], a plausible explanation for our observation is that a smaller amygdala may provide protection from the emergence of PTSD following childhood trauma, or may facilitate recovery from PTSD.  (Teicher/nc/35)”

++++

“The amygdala appears to play a crucial role in fear conditioning and in the control of aggressive, oral, and sexual behaviors [100].  Episodic dyscontrol and impulsive violence may be due to irritable foci in the amygdaloid nuclei [100].  This region may also be involved in the formation and recollection of emotional memory, the learning of non-verbal motor patterns, and the triggering of flight-or-flight responses [101].  Excessive amygdaloid activation has been proposed to play a crucial role in the development of PTSD [37,102-105] and in major depression [106].  (Teicher/nc/37)”

“Seizure foci producing partial complex seizures are often localized to limbic structures in the temporal lobe.  Both hippocampal sclerosis (characterized by neuronal loss in the dentate nucleus and in the CA1 and CA4 sectors of the hippocampus) and amygdaloid damage have been observed in a significant proportion of patients with TLE [temporal lobe electrophysiology?] [107,108].  One controversial, potential consequence of abnormalities in temporal lobe electrophysiology may be a tendency toward aggressive behavior.  For example, Bach-Y-Rita [109], in a study of 130 violent patients with histories of childhood deprivation, parental psychiatric illness, and family violence, found that one half of all patients receiving EEGs showed abnormalities, particulary temporal spikes.  (Teicher/nc/37)”

“EEG abnormalities may be a significant risk factor for suicidal ideation or attempts….The risk of completed suicide is 4-5 times greater in epileptics than among non-epileptic patients and may be 25 times greater in patients with temporal lobe epilepsy [112,113].  As many as one third of all epileptic patients have attempted suicide at some point in their life [114,115]….  (Teicher/nc/37)”

++++

this is cc from limbic system – first part is in thalamus

“The neuroanatomy of the olfactory tract is unique among the senses.  Hearing, a small part of vision, touch, and taste all enter the brain through the brainstem and are passed up to the thalamus.  From this central way station, millions of neural networks transfer signals to regions of the cortex specialized for each sense.  The signals are bounded around, then sent on for further processing to the limbic system, which is central to emotions, memory, pleasure, and learning.  The limbic system often adds an emotional tag…. It calls up memories and may initiate a bodily response….  As an emotional response is evoked, a person may begin planning a proper course of action.  (Ratey/ug/63)”

“Given the complexity of visual and auditory information, and the corresponding potential for misinterpretation of ambiguous situations, the brain tries to make sense of fine details before making a judgment call.  In contrast, olfactory nerves project directly into the amygdala and olfactory cortex, parts of the limbic system, without any mediation through the thalamus.  The olfactory nerves have a hotline to the emotional brain, and only then is the information sent to the orbitofrontal cortex for more associating, inhibiting, and further processing.  The “smell” connection is much faster and more decisive than the systems for the other senses and not much filtering goes on before action is called for by emotional memory.  (Ratey/ug/63)”

“Indeed, the nostrils are positioned directly above the mouth because they serve as a last-resort alarm system.  If you are about to eat something that is disgusting and would make you sick, the olfactory system must be able to detect the (Ratey/ug/63) telltale odor, match it to a memory encoded in the limbic system, and alter your behavior, all in the fraction of a second that it takes for a morsel of food to pass beneath the nose to the lips.  (Ratey/ug/64)”

“The direct route traveled by olfactory information is a holdover from early evolution, when quick, emotional responses to odors played a crucial role in survival.  Smell is also different from the other senses in that its machinery (the olfactory network) remains uncrossed.  All the other senses send most of their information through the thalamus to the opposite hemisphere of the brain for processing.  (Ratey/ug/64)”  cc to thalamus

++++

“Smell, it seems, also has the power to influence brain functions that affect psychopathology.  As noted, axons from the olfactory bulbs connect to the amygdala, a structure in the limbic system essential to nurturing behavior and fear-conditioning.  Removing the amygdala causes animals to neglect their young and to forget the negative associations that they have previously formed with particular stimuli.  Over-sensitivity of the amygdala has been implicated in anxiety, panic disorder, posttraumatic stress disorder (PTSD), and attention deficit hyperactivity disorder (ADHD).  The amygdala receives stimuli from every sensory modality, though none as directly as olfaction.  (Ratey/ug/66)”

next part is in hypothalamus

++++

“Olfactory projections are also found in the hypothalamus, the brain’s hormonal center, which is responsible for the fight-or-flight response.  Consequently, odors can alter heartbeat and blood pressure (Ratey/ug/66) directly, with very little mediation.  Olfactory fibers also project into the pleasure areas of the limbic system, including the amygdala and the septal area, where dysfunctions are seen in schizophrenia, addictions, ADHD, and the ability simply to feel satisfied.  (Ratey/ug/67)”

++++

“…very few individuals are capable of “imagining” smells very well, either by hearing a word or visualizing something particularly odorous.  This inability may be due to the relatively small area of higher cortex devoted to olfaction.  However, smells are strong prompters of memories, because the olfactory nerves are wired directly to the hippocampus and amygdala, which are crucial to memory.  (Ratey/ug/68)”  cc to amygdala

++++

“…very few individuals are capable of “imagining” smells very well, either by hearing a word or visualizing something particularly odorous.  This inability may be due to the relatively small area of higher cortex devoted to olfaction.  However, smells are strong prompters of memories, because the olfactory nerves are wired directly to the hippocampus and amygdala, which are crucial to memory.  (Ratey/ug/68)”

++++

“…taste signals enter the brain at the medulla in the brainstem from three cranial nerves.  From the nucleus solitarius, the arrival area in the medulla, signals are sent to the thalamus and then on to the taste centers in the cortex, which sends them on parallel pathways to the hypothalamus and amygdala, and then on to other parts of the limbic system, where emotions and memory are stored and retrieved in regard to qualities of the taste.  This can cause us to avoid food that tastes a certain way or seek food that can satisfy the nutritional needs of the body, such as salt. The signals traveling back and forth along these pathways also affect consumption reflexes such as salivating and swallowing.  (Ratey/ug/71)”

“The hypothalamus plays a key role in feeding mechanisms…..problems in the lateral hypothalamus area cause the animals to stop eating and drinking, while lesions in the ventromedial nucleus of the thalamus cause overeating.  (Ratey/ug/71)”

“Areas in the thalamus and hypothalamus are involved in feedback patterns that maintain the body’s energy balance and body weight.  Decisions about whether to eat or drink, what to eat or drink, whether to continue eating or drinking, and when to stop eating or drinking – the balance between eating and satiety – result from the interchange between these areas.  Since the hypothalamus is also a key play in the motor system, emotions, and memory, it is believed to control our hunger by triggering the release of dopamine, which is greeted as a (Ratey/ug/71) reward by our reward system.  When these areas determine that satiety has been reached, the dopamine is stopped, and our desire to eat wanes.  (Ratey/ug/72)”

++++

“The act of rubbing your knee [after an injury] also produces an effect that releases morphiinelike opiates.  The opiates bind with and excite opiate receptors in the amygdala and the hypothalamus, resulting in signals to the medulla that feed back to the spinal cord, countering incoming signals from the nociceptors and diminishing the transmittal of pain information to the brain.  (Ratey/ug/88)”  cc to file

++

CC TO CORTEX

“Just the same, the pain signals continue to the

amygdala, home to the body’s warning system against potentially harmful or life-threatening situations.

If pain is going to be a threat,

the amygdala,

which is responsible for fear, startle, and autonomic reactions,

will respond with the signal to fight or flee.

This allows us to react quickly to a harmful or dangerous situation involving pain.  After the relevant pain information has been processed in the amygdala, it is sent up to the frontal cortex for higher-order processing and our bodies’ response.  (Ratey/ug/88)”  unless this reaction has been “messed up?”

++++

“pain signals are sent to the brain when the nociceptors are activated….  This activation is triggered when a cell is damaged and releases a chemical called adrenosine triphosphate (ATP).  The ATP molecules bind with the nociceptors, and the alarm signals begin.  (Ratey/ug/88)”

++++

“The primary emotional signal the anterior cingulate gyrus receives

comes from the amygdala,

at the core of the limbic system,

which influences attention by assigning emotional significance to incoming information.

Even before a sensory perception has reached the frontal lobes,

where it enters conscious awareness and undergoes fine categorization,

the amygdala has already branded it

with a raw emotional valence somewhere along a continuum from mildly interesting to “oh my God!”

It activates the body and the rest of the brain in response to how significant it deems the stimulus to be to survival.

If the stimulus seems threatening, it activates the alert centers [what are these alert centers?] of the brain and notifies the hormone system and brainstem to get ready to rock and roll.  (Ratey/ug/121)”  cc to relevant files

“The amygdala provides a

preconscious bias of intensity to every stimulus you come into contact with,

even before you actually pay attention to it.

It can, and does, operate outside consciousness.

One example is its ability to immediately prepare us to flee when we perceive an exploding noise, long before the cortex has begun to make sense of what the noise is.

People without an amygdala owing to infection, stroke, or surgery have what we call the Kluver-Bucy syndrome, a bizarre set of symptoms with a

tendency to react to all stimuli in the environment without discrimination or learning.

They also have a marked indifference to people and lose their emotional attachment to family members. (Ratey/ug/121)”

That’s interesting – indifference to people and lose their emotional attachments – how does this relate to the smaller amygdala in people with no PTSD symptoms, but with BPD?  And to difficulties with empathy?

Does smaller amygdala mean less empathy”  Does less empathy mean smaller amygdala?

++++

“By anticipating events, the amygdala’s emotional tagging, which occurs in consultation with our memories, allows us to instantly judge and then react to the world.  If a stimulus is deemed dangerous, the amygdala adds impetus to the attention system to “keep arousal going.” However, s emotions can also be a hindrance if they cause us to prejudge the environment.  People with depression, for example, may not respond to attempts by others to help them feel optimistic because they are constantly tagging stimuli with the label “sad.”  (Ratey/ug/121)”  I doubt the brain sees this as a label!  It is not that they are tagging it sad, the amygdala is doing it preconsciously and instantly as a reaction!  His statement irritates me – it is not a whole truth, but a bias on his part, and not accurate.

“How does limbic tagging occur?  Dopamine may again be the key.  It is abundant in the amygdala, and both the amygdala and the closely linked

striatum,

the home of the nucleus accumbens,

have been shown to

release dopamine in response to pleasurable rewards or painful (Ratey/ug/121) punishments.

Whether the experience is registered as painful or pleasurable, however, seems to be less important than the intensity of the pain or pleasure.  In this fashion, a person learns to associate positive or negative emotions with an event.  (Ratey/ug/122)”

++++

“Motor activity is affected by many factors, including some we may not immediately think of, such as motivation.  The anterior cingulate gyrus, also on the second floor, appears to play a crucial role in initiation, motivation, and goal-directed behaviors.  It is well interconnected with the amygdala and other structures of the limbic system that regulate our emotions, the fight-or-flight mechanism, and conditioned emotional learning.  In short, it assesses just how important something is, determines an appropriate response, and decides how quickly the response will be executed.  (Ratey/ug/165)”

++++

FIGHT OR FLIGHT

“The most fundamental attention system involves the fight-or-flight response.  Understanding how it works illustrates how attention, emotion, and motor systems work with and on each other. (Ratey/ug/171)”

“Suppose you are walking down an avenue in a busy city, following directions to an apartment you’ve never visited.  A bit lost, you venture down a dark, cluttered alley. Suddenly you hear a loud, crashing sound behind you.

Signals from the ears head toward the cortex.

On their way, some of the signals take a short side route to the amygdala, which checks whether an immediate response is needed.  This tiny cluster of brain cells shouts, “What is that?  Search for it.  Find out.  Alert!”  to the

autonomic nervous system.  (Ratey/ug/171)”

++

autonomic nervous system

“The autonomic nervous system oversees the body’s vital functions through subconscious signals that originate in the anterior cingulate and are relayed to the hypothalamus and the spinal cord.  It has two reciprocal and complementary branches:  the sympathetic and the (Ratey/ug/171) parasympathetic nervous systems.  These send out neurons to regulate the internal organs, such as the heart, lungs, stomach, and genitals.  They balance and offset each other to keep the body in just the right tone automatically and without our being aware of the changes.  This frees up the cortex to pursue the conscious services of sight, speech, hearing, thinking, emotion, and voluntary movement.  (Ratey/ug/172)”

“The instant after the amygdala shouts emergency, the parasympathetic nervous system ever so briefly suppresses the heart rate, breathing, and other internal functions.  It quiets all systems so you can fully take in information and focus on perceiving and evaluating, and creates a bodily delay so the cortex can efficiently assess what that sound might be before you respond to it.  (Ratey/ug/172)”

An instant later, however, the sympathetic nervous system is driving up your blood pressure, pulse, and breathing, and producing adrenaline so that your muscles can spin you around and prepare you for fight or flight.  (Ratey/ug/172)”

“As this is happening, the perception and alert signals reach the frontal cortex, which evaluates the situation and decides whether or not there is danger.  If it determines that a cat has tipped over a metal can, it calms the amygdala down, saying, “There’s nothing to fear.”

Signals from the sympathetic nervous system reverse.  Your blood pressure comes down and your heart rate returns to normal.

The lower brain surrenders some control to upper portions of the brain.

You begin to “think” about what is happening rather than just responding.  (Ratey/ug/172)”

++

“If a wild-eyed man is waving a gun in the air, signals are sent immediately to the hypothalamus.

Unlike other responses that require a decision-making process, this response bypasses the upper cortex, so immediate action can be directed.

Because it plays a crucial role in the regulation of body systems, the hypothalamus is often referred to as the brain of the brain.

CRF, the brain’s own stress hormone, is released,

which heightens anxiety and vigilance and eventually sends instructions to the adrenal glands to release

epinephrine (adrenaline) and – are these the same thing??

cortisol, the “stress” hormone, to prepare you for action. – this is what is so deadly to the traumatized infant’s brain development!

The hypothalamus also directs the pituitary gland, the body’s master gland, which secretes hormones affecting every major gland of the body.  These systems reactivate the amygdala and the brainstem, triggering the sympathetic nervous system to put the body into overdrive so that you can run like you’ve never run before.  (Ratey/ug/172)”

“How these systems respond in the case of surprise to an unfamiliar alley or in situations that are not life-threatening depends to some (Ratey/ug/173) on a person’s history.  Individuals who are generally calm will spend fractions of a second more time in the parasympathetic response, to better gather information and evaluate before they react.

IMPORTANT

But people who have a history of overresonding may flee, or at least hurry off, even if they do not perceive an obvious danger.  People who are anxious develop an overly efficient neural pathway from the amygdala to the sympathetic response.  If this pathway is too well hewn, the brain is instantly hyperaroused to “Attend!  Attend!  Attend!”  This excessive signaling makes it impossible for the frontal cortex to focus, because the noise and the strong panic signal commandeer the bulk of the frontal cortex’s resources.  (Ratey/ug/173)”

“This kind of “hyped up” response mechanism is what can cause performance anxiety [which really is what a shame response is].  If people who have histories of being anxious in front of a group have to step up to a podium on stage and give a speech, they may get thrown into a hypervigilant response mode.  Their anxiety arouses the sympathetic nervous system.  This, in turn, starts hormonal and cellular reactions that cause their muscles to tense.  Heart rate and blood pressure go up and breathing gets shallow.  These physiological changes send an attention signal back to the brain saying, “You’re tense, you’re tense, you’re tense.  Oh boy, this is bad news, this is bad news.  Check everything.”  An upward spiral of anxiety is initiated; the feedback loop amplifies itself and becomes louder with each cycle.  Once again, the strong signal commands too much of the frontal cortex’s resources, and there isn’t enough left for the cortex to put together the ideas in the speech, or perhaps even to coordinate the motor commands for the moth and vocal chords.  Such speakers are “struck dumb.”  [this is kind of what it’s like for me those times when I cannot answer a question under social pressure.]  The resulting message to the brain that sounds are not coming from the mouth of course amplifies the anxiety even more.  Game over.  Take a seat.  (Ratey/ug/173)”

“Some people who are prone to high anxiety and yet must do things such as give speeches get help from drugs called beta-blockers, such as propranolol and nadolol.  These block adrenaline – the adrenal hormone – from pumping up in the large muscles, which causes them to become tense when preparing for fight or flight.  They also act to lower blood pressure and pulse, breaking the spiraling feedback between body and brain.  (Ratey/ug/173)”

“Ironically, a little bit of performance anxiety can be a good thing.  Many actors, for example, say that they actually welcome a touch of stage fright because it “puts them on edge” and gives their perfor- (Ratey/ug/173) mance more passion and energy.  The heightened attention and emotion systems engaged in a degree of survival response drive them to a superior performance by activating keener attention in the frontal cortex.  Indeed, a mild amount of stress and activation is what constitutes stimulation.  (Ratey/ug/174)”

++++++++++++++++++++++

“Movement is a physical expression of e-motion.  (Ratey/uf/174)”

I think I will specify this e-motion as being those basic emotions that are in the body – the ones the body responds to automatically.

“For example, long before we feel sad, a thought is triggered either from memory, a current situation, or an imagined future.  (Ratey/uf/174)”

This is a contradiction to what he just said about overloading the cortex or bypassing it completely.  See amygdala, anterior cingulate gyrus

“As this is happening, an array of chemicals and hormones are produced that act as internal messengers throughout our bodies.  The physiology that is created changes how we “feel” internally.  (Ratey/uf/174)”

“Our internal feelings, or emotions, can also lead to physical changes, such as the production of tears by the tear ducts.  Bodily states such as breathing, blood pressure, pulse, and heart rate may change as well.  (Ratey/uf/174)”

“We and members of other species communicate our emotions primarily through facial gestures[how does this correspond to what Schore or Siegel said about only humans having these special nerves?] These and other expressions of emotion such as crying and laughing are controlled by the amygdala and brainstem.  The best evidence for this comes from a disorder known as pseudobulbar palsy, which is caused by damage to the outputs of the (Ratey/uf/174) motor cortex, on the second floor.  Individuals with this disorder cannot make voluntary movements of facial muscles; however, external events can still elicit laughter, tears, and facial gestures of emotion.  They are responding with the first floor, which is still intact.  (Ratey/uf/175)”

“What’s even more fascinating is that the motor control of movements related to emotion is not in the same location as the control for a voluntary movement of the same kind.  For example, when a stroke destroys the motor cortex in the brain’s left hemisphere, the patient experiences paralysis on the right side of the face.  When asked to smile the patient cannot move the right side of his mouth.  However, when the same patient is told a joke and laughs spontaneously, the smile is normal; both sides of the mouth move as they should.  The cortex cannot exercise its usual control over the muscles, but the muscles still respond to the more automatic and implicitly learned responses that are located on the first floor – the basal ganglia.  (Ratey/uf/175)” cc last 2 paragraphs to basal ganglia

++++

“Consider the effect of mood, for example.  The frontal cortex is the part of the brain that neatly organizes the bits and pieces into a temporal, logical, and “meaningful” story.  However, it must be set in motion by the amygdala, which provides an emotional tag to a memory, a “meaning” that helps cement the pieces.  [glue]  Given this, one’s emotional state at a given instant affects how the amygdala processes the emotional tag of a memory, perhaps changing ever so slightly how that memory is reconstructed.  An individual who is depressed is predisposed to see a certain memory in a negative light – so it’s a different kind of memory than it would have been had the person been generally happy.  (Ratey/ug/186)”

++++

“The model of memory as a set of distributed pieces that are pulled together on demand, the need to repeat the firing patterns to etch them into long-term memories [well, obviously flashbulb memories are different than this], and the role of LTP in making this happen are all supported by modern sleep research.  The culmination of decades of work by researchers such as Allan Hobson at the Massachusetts Mental Health Center shows that brain wave activity in the hippocampus during dreaming actually rehearses memory patterns, either to harden newer experiences into long-term memories or to keep fading connections alive… The mechanism most cited is the cortex’s processing sensor information during a new experience and sending it to the hippocampus, which initiates replay and consolidation of the experience into long-term memory during sleep.  (Ratey/ug/192)”

“…during REM sleep there is communication between the amygdala, (Ratey/ug/192) the anterior cingulate gyrus, and the occipital lobes, structures that have long been linked to attaching emotional significance to memories and dreams.  (Ratey/ug/193)”

“More evidence comes from the evolutionary ladder.  In the one mammal that does not experience REM sleep, the spiny anteater, the prefrontal cortex – the major center of learning and behavior – is so disproportionately large relative to the animal’s body mass that memories are encoded at the moment an event is first experienced.  Higher mammals, lacking this massive reservoir, were perhaps forced to develop and reserve REM sleep as a time for solidifying memories; recall the study showing that the exact neuronal firing patterns present when rats explored a maze were repeated precisely when the rats were in REM sleep.  (Ratey/ug/193)”

++++

“A recent study by Antonio Damasio has pinned down the brain regions involved in this mismatch.  (Ratey/ug/210)”

“Damasio concluded that emotional conditioning is dependent on the amygdala

and that emotions are processed independently of the events with which they are associated.  (Ratey/ug/211)”

“There is a limit, however.  If the emotional arousal is too high, the hippocampus is hindered in making a proper categorization and evaluation of the traumatic event.  (Ratey/ug/211)”

“What happens, chemically, is that a traumatic experience or painful memory – or a high incidence of stress, for that matter – causes the level of cortisol in the brain to rise.  (Ratey/ug/211)”

“Cortisol, the stress hormone, works by binding to receptor sites in the hippocampus, but when emotion gets too high too much cortisol binds to each neuron.  (Ratey/ug/211)”

“The onslaught increases the metabolism of the cells so much that they essentially overheat and die.  (Ratey/ug/211)”

  1. (Ratey/ug/211)”

The traumatic experience is recorded as separate and dissociated from other life experiences, and takes on a timeless and alien quality.  (Ratey/ug/211)” cc to brain chemicals and amygdala

++++

The Feeling of What Happens:  Body and Emotion in the Making of Consciousness

Harcourt Brace & Company

1999

Antonio R. Damasio

++++

chapter ten Using Consciousness

“We know from the situation of patients who lose the covert biasing system – patients with damage to the ventromedial prefrontal cortex or to the amygdala – that the decision apparatus is impoverished to a dramatic degree.  This indicates that the nonconscious system is deeply interwoven with the conscious reasoning system such that the disruption of the former leads to an impairment of the latter.  (Damasio/FWH/302)”

“But in the situation of a person without neurological disease, in which both the nonconscious and conscious systems are present and normal, it is apparent that the conscious component extends the reach and efficacy of the nonconscious system.  Consciousness allows the player to discover if the strategy is correct and, in case it is not, to correct the strategy.  Moreover, consciousness allows the player to represent the context of the game and decide if he or she should stop playing it or wonder about the possible value of the situation for the player or for the examiner.  (Damasio/FWH/302)”

++++

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