JOSEPH LEDOUX AND THE AMYGDALA

The Amygdaloids

Joseph LeDoux, vocals and guitar; Tyler Volk, lead guitar and vocals; 

Nina Curley, Bass; and Daniela Schiller, drums

It has taken a while to read enough material to understand how various the brain neuron researchers are and what that implies in terms of what they study.  More reading is necessary because things are happening so quickly and in so many different ways.  Joe LeDoux is quite explicit about dissecting out what he works on and why he thinks as he does.  So far as I know, he’s the only one with a band, the Amygdaloids, and the only one with a video blog.  He reminds me of Saul Bellow, which is partly about his stingy brim hat and partly about his clear openness.  http://www.amygdaloids.com

But he doesn’t spare sensibilities.  To locate the two amydalae, one on each side of the brain, he suggests one imagine an arrow thrust into the ear and another one thrust into the eye and where they meet, that’s where the amydala on that side is located.  Part of this little organ is almond-shaped, so the early anatomists gave it that name, but it turned out that there are other pieces attached to the “almond” which makes the organ quite differently shaped.  Also, it is tightly wired to the surrounding cortex with strands of neuron. 

There are basically two nerve systems in the body, so different that some of the controlled muscles are smooth (autonomic: guts) and some are striped (striated: voluntary muscles).  It has served me well that I took high school physiology from Miss Jean Hill at Jefferson in 1955.  A small brisk woman with a female partner, she made everything so clear and memorable that it has been a reliable foundation.  But now that scientists are tracing where the neuron impulses go and what they do, instead of relying on shapes of the tissues and physical connections, the autonomic systems turn out to be a little different from what we thought then.

http://blogs.scientificamerican.com/observations/2014/06/30/free-will-is-your-brain-the-boss-of-you-video/

Gazzinaga, another key brain neuron researcher.  A no-tie guy.  (California)

LeDoux does NOT address the issue of free will, nor the relationship between the tissue of the brain and the self-conscious mind, nor the functions of the pre-frontal cortex, nor the origin of consciousness, though all these are hot topics.  Rather he is focussed on the function of the amygdala, which appears to be the switchboard of the brain functions that are "under" consciousness, and yet are the great bulk of what goes on in the brain.  The brain NEEDS a switchboard because it’s real job is sorting and weighting the information that comes in through many different sources and channels -- then deciding what to do about it.  But the amygdala doesn't wait around for speculation: it just reacts.  REFLEXES. 

True enough, everything in the beginning comes from the world outside the skin through the sensory organs and cells, which are more subtle and ingenious that we ever knew.  The grid cells, compass cells, mirror cells, and others yet to be discovered, are in the prefrontal cortex.  The eyes and nose are so connected to the brain that some consider them brain parts.  And so on.  But two things are recent discoveries.  One is the many sorting “matrixes” or nexuses or what LeDoux calls “buffering” centers, at least as many as there are major senses, each with the power to edit, weight, or block neural information.

http://blogs.scientificamerican.com/observations/2014/08/20/how-does-our-brain-remember-video/

Eric Kandel, a bow-tie guy (NYC)

And another is that the amygdala gives priority to anything that would threaten survival: tigers, snakes, sudden strangeness in general.  It triggers reactions before a person even knows they will act.  The person doesn’t have control over this.  Some reactions appear to be hard-wired and some seem due to conditioning so intense and instant that it can never really be undone.  A little boy abused as a toddler before he is able to form enough brain function to remember consciously will, as an adult, react to that undermemory to the extent of his ability to fight, flight or freeze.  It cannot be erased.  If an abused kid was thought to be “safe” to molest because he hasn’t learned to talk, he might still be able to tell the story through his body’s reactions to the amygdala's monitors.

Moving on to another kind of memory is the complex in the hippocampi, two little “sea horses,” one over each ear.  This is where one stores sensory information, consciously acquired information, and memory of strategy that worked -- all the prefrontal cortex stuff.  The primary neuronal code that comes into the brain is routed by the thalamus to either the amygdala system or the hippocampus system.   After that, they don’t communicate, though the hippocampus system might remember the emotion connected to a memory. 

This is the way we understand it now, at least how I understand the enormous, complex and technical content of books like LeDoux’:   “The Emotional Brain: the Mysterious Underpinnings of Emotional Life.”  It is rewriting, or at least reframing, the Freudian theories, which is very helpful in dealing with things like PTSD.  Until now these two systems of thought have been as separated as the two physiological systems, but they have a lot to say to each other.  Freud was frustrated by not being able to get at the very things our machinery can record now.

The following are the steps of how things from outside the skin are brought into the body and transformed into identity and “mind.”

Aplysia fasciata:  research sea slug

1. Physical responses to the environment are universal among all living things, even invertebrates.  It is the definition of “living.”  There is a constant flow of interactions in the body.  There is no such thing as “emotionless” in a living vertebrate creature.  Invertebrates have no amygdalas, but what the amygdala does is done in the cell. 

2.  Feelings are the reactions of the brain/body, the stuff that could be measured on a lie detector test, but aren’t necessarily conscious.  This is what LeDoux is getting at: that the changes perceived and recorded in the amygdala and the cerebral cortex surrounding it, plus the wiring that reaches into older parts of the brain clear back to the brain stem, partly because of evolution and partly because of evolving alternative ways of perceiving, is very DIFFERENT and not accessible to the hippocampus-mediated re-consolidated memories, which are themselves undependable.  (Not because they are lies, but because they are reassembled from various sources, not always in the same pattern and sometimes including extraneous material.)

3.  Emotion never stops but is overlain and restrained, formed into the person’s awareness of self and ability to project an idea of what to do.  Stress will throw people back to their earliest conditioned reflexes, especially those involving trauma.

Much fancier sea slug suggesting hair on fire!

4.  Naming the emotion (happiness, rage, sadness) happens after the emotion has become conscious.  But it can control behavior without ever having a name.  There have been three approaches to LeDoux’s sort of material.  One was the idea that all emotion was in the “limbic”  middle third of the brain.  The idea of the “limbic” came undone when there were too many cross-connections to claim the middle third of the brain was a separate entity.  Then there was the reflective idea that there were six or five or seven basic emotions, each managed by a different system -- but that fell apart.  Then there were theories about “arousal” -- sort of parallel to the Hans Selye idea of one basic unified response to stress.  So?  None really worked.

5. Behavior triggered by emotion can convert to something besides violence and more sophisticated than flight or freezing, but the emotion itself remains.  Fifty per cent of mental disorders are the result of fear and anxiety (“fear lite”) that are not quite managed well enough to keep them resolved.  FEAR is the big controller in our American “civilized” society even more than in the close-to-the-land villages of Africa.  I mean it is consciously and cynically used in politics, marketing and religion.

Do not mock or tease a kid in melt-down.

He will associate you with distress.  Give him space and, when he's ready, comforting.

6.  Social attitudes about the behavior produced by the emotion are both responsive and shaping.  How people react to strong emotion in others certainly influences their attempts to control themselves or even explain themselves.  But people rarely understand the basic physiological connections between a stimulus, the perception of it, and what the person has learned in a deep amygdalan way.  That is, in our culture we don't explain, comfort or make space.  Instead we come down hard on the behavior and try to extinguish it with punishment.  What we create is a gasoline piston which compresses the fuel until a spark sets off an explosion.  This is especially true for boys.

Most of LeDoux’s work is practical and at the cellular and molecular levels.  An amygdala has a dozen parts, only three of which control fear responses.   One of the three is connected directly to the brain stem, the earliest "brain" structure.  The team is using optogenetics to test many people so as to build a bell curve of reactions in different individuals.  Then the subjects are tested to see what different drugs can do.  In the past norepinephrine has been considered key.  The team sometimes uses propanalol, which was what sedated Michael Jackson to death.  It seems to shuts off fear.  Sometimes it's used to suppress stage fright.

Twenty per cent of the rat subjects failed to become conditioned by scientific funny business with shocks and barriers and rewards.  At first the experimenters thought they were Braveheart rats who had no fear, but more investigation revealed that they were actually feeling the fear, but somehow molecularly suppressing the reaction to it.  Is courage not being afraid or acting brave in the face of lethal danger?  For rats, we now know it might be either.  It was like the situation of the pigs routinely killed with succinylcholine because they looked so peaceful.  But they were only paralyzed.  Lie detector equipment revealed they were beyond terror, screaming inside.  

Like children assaulted but too afraid to show what they felt.  For the rest of their lives they will be trapped between terror and rage, denying both, looking for survival.  No wonder we recognize super monsters.

https://www.youtube.com/watch?v=zRuUQiIgyj4    Using proper timing and drugs, we can now block memories, as described in this vid.  But, as usual, we have ethical issues.  More to read and think about.