Posts Tagged ‘neocortex’

Sensitivity to Context

April 1, 2020

Prof. Davidson notes that failing to correctly discern social context can lead to emotional responses that are appropriate in one setting but not in another. It’s appropriate to feel extreme anxiety in dangerous situations but not in other situations; if you can’t tell the difference, you are at risk for post-traumatic stress disorder.

Prof. Davidson continues, Based on the success of exposure, we can surmise that a general strategy to enhance Sensitivity to Context is to gradually insure yourself to cues that make you anxious or angry:

To help you relax, start with a simple breathing technique from hatha yoga. With your eyes closes, attend to your breathing as you would in mindfulness meditation, counting the duration of each inhalation and exhalation.
Once you have counted for several breaths, lengthen your breathing cycle so it takes you one more second. Keep increasing the lengths as long as you feel comfortable. then maintain these longer breaths for five minutes.
Notice if the inhalation and exhalation are the same length. If one is longer, try to lengthen the other so that they take equal amounts of time. Do this for five minutes and then open your eyes.

Once you feel comfortable with this breathing exercise, move on to context training. Prof. Davidson uses the example of a boss who makes you so anxious that you start sweating just thinking about him, with this anxiety spilling over into your family life. The same principle would work with any source of anxiety or dread:

Make a list of the specific cues and behaviors of your boss that upset you. Maybe he looms over your desk during the workday. Maybes loiters outside your work space at 4:55, watching to see if you leave even a minute early. Maybe he excoriates the reports or other work you turn in. Be specific and vivid and detailed as possible.
Then, in a safe context such as at home on a weekend, gently and gradually bring to mind images associated with your boss. Conjure up exactly how he looks watching you at day’s end. Imagine his face as he reads your work.
Simultaneously, perform the breathing exercise. Continue to do this until you feel comfortable and relaxed imagining your boss’s glowering visage and his habit of hovering over you desk. Spend about fifteen minutes on this exercise.

Prof. Davidson writes, you can expect to experience some benefit after doing this for four sessions, and the hour you invest will be well worth it. By improving your ability to distinguish between the context of your work and home, this exercise should help you distinguish among other contexts, too, and thus display context-appropriate emotional responses. Although there have not been any studies comparing brain activity before and after such training the fact that exposure therapy helps PTSD patients suggest that it works by strengthening connections from the hippocampus to the prefrontal cortex and other areas of the neocortex.
Prof. Davidson continues, there has been no research explicitly focused on moving people to the Tuned Out end of the Sensitivity to Context continuum, or on ways to weaken connections from the hippocampus to the prefrontal cortex and neocortex. But if you feel that shifting your set point away from the Tuned In extreme would help you stop tailoring you behavior to each context in a way that feels excessively contrive, I recommend the exercises that cultivate Self-Awareness.

Much more extensive guidance is provided in The Six Dimensions of Emotional Style
How Its Unique Patterns Affect the Way You Think, Feel and LIve—And How You Can Change Them by Richard J. Davidson, Ph.D. with Sharon Begley.

31st Meeting of the Association for Psychological Science Pt. 2

June 3, 2019

A definite highlight of the meeting was lecture by Lynn Nadel titled, Taking James Seriously: The Implications of Multiple Memory Systems. The James referred to in the title is William James, the father of American Psychology. James wrote about multiple memory systems, a primary and a secondary memory, which today are referred to as short term and long term memory. He made a distinction between habits and memory.

James passed away long before the emergence of neuroscience. The hippocampus plays an important role in the processing of memories. There was a famous epileptic patient referred to as HM who had large portions of his temporal lobes removed. A hippocampus is located in each one of those lobes. Although his previous memories remained intact, not only each new day, but each new hour was a new experience for HM. And these experiences would not be remembered.

There is a distinction between episodic memory, which holds the memories of our daily experiences is processed in the hippocampus, and semantic memory, which holds our general knowledge of the world, is resident in our neocortex.

The hippocampus is also critical to navigation. The neuroscientist O’Keefe identified place cells in the hippocampus. These place cells identify spatial locations where the organism travels. Learning to navigate entails strengthening these place cells and learning to follow them to desired locations.

In most species, the hippocampus matures postnatally. This has important consequences for memory and cognitive development. Dr. Nadel asks what does it mean to start life with a developing, but not yet functioning hippocampus, perhaps uniquely susceptible to impacts of experience early in life. In humans it takes 18-24 months for the hippocampus to emerge, and it takes 10-12 years for it to become fully functional.

Dr. Nadel speculates that phobias can develop before the hippocampus emerges. This late emergence of the hippocampus explains infantile amnesia and delayed exploration and place learning. Everything we learn very early in life is context free. The individual has no understanding of why she has certain fears, as the cause of the fear was not stored in memory. As for the 10-12 years for the hippocampus, an extremely important structure, to become fully functional, it might result in shortcomings in learning and interpersonal interactions.

The Creative Brain

February 26, 2019

The title of this post is the same as the title of a chapter in Daniel Goleman’s book “The Brain and Emotional Intelligence: New Insights.” The chapter begins,
“‘Right brain good, left brain bad.’ That belief about creativity and the right and left hemispheres of the brain dates back to the Seventies, and reflects a very outdated bit of neuromythology. The new understanding about left and right hemispheres is more specific to the topography of the brain: when it comes to left versus right, do you mean left front, left middle, left rear?”

The right hemisphere has more neural connections both within itself and through the brain. It has strong connections to emotional centers like the amygdala and to subcortical regions throughout the lower parts of the brain. The left side has far fewer connections with itself and beyond to the rest of the brain. The left hemisphere is made of neatly stacked vertical columns, which allow the clear differentiation of separate mental functions, but less integration of those functions. The right hemisphere is more of a mix structurally.

Brain studies on creativity reveal what goes on that “Aha!” moment, when we get a sudden insight. When EEG brain waves are measured during a creative moment, it turns out there is a very high gamma activity that spikes 300 milliseconds before the answer comes to us. This gamma activity indicates the acting together of neurons, as far-found brain cells connect in a new neural network as when a new association emerges. Immediately after that gamma spike, the new idea enters consciousness.

This heightened activity focuses on the temporal area, a center on the side of the right neocortex. This is the same brain area that interprets metaphor and gets jokes. This high gamma spike signals that the brain has a new insight. At that moment, right hemisphere cells are using these longer branches and connections to other parts of the brain. They’ve collected more information and put it together in a novel organization.

In spite of what you might have read or heard, there are two primary modes of creative thinking. The first is to concentrate intently on the goal or problem. The next stage is to let go. During this stage you are relaxing and letting your non conscious brain do its creative thing. This stage is characterized by a high alpha rhythm, which signals mental relaxation, a state of openness, or daydreaming and drifting, where we’re more receptive to new ideas. This sets the stage for novel connections that occur during the gamma spike. Of course, after that “aha moment” you need to return to concentration to evaluate the creative idea and asses how adequately it addresses the problem.

In all but rare cases, this is an iterative process. And this iterative process can occur over the course of years. There are documented cases of mathematicians trying to solve a problem. The problem appears to be intractable, because the “aha” moment never seems to come. But, sometimes it eventually appears seemingly from nowhere.
The name of this process is incubation, because you are not consciously trying to solve the problem. However, your non conscious mind has been working on this problem, perhaps even when you thought you were sleeping.

Goleman concludes the chapter with a final state, implementation. Here’s where a good idea will sink or swim. He remembers talking to the director of a huge research lab. He had about 4,000 scientists and engineers working for him. He told Goleman,”We have a rule about a creative insight: if somebody offers a novel idea, instead of the next person who speaks shooting it down—which happens all to often in organizational life—the next person who speaks must be an angel’s advocate someone who says, ‘that’s a good idea and here’s why.” Goleman writes, “Creative ideas are like a fragile bud—they’ve got to be nurtured so that they can blossom.”

Different creative people use different processes, so there is no optimal way of being creative. Each creative person creates her own creative process, which might even vary from problem to problem.

The Seat of all Passions

March 9, 2018

The title of this post is the title of a section in Daniel Goleman’s book “Emotional Intelligence.” In humans the amygdala (from the Greek word for “almond’) is an almond -shaped cluster of interconnected clusters perched above the brainstem, near the bottom of the limbic ring. There are two amygdalae, one on each side of the brain nested toward the side of the head. Our amygdalae are relatively large compared to that of any of our closest evolutionary cousins, the primates.

The amygdalae and the hippocampi (there is also a hippocampus on each side of our brains) were the two key parts of the primitive “nose brain” that gave rise to the cortex and the neocortex. These limbic structures do much or most of the brain’s learning and remembering; the amygdalae is the specialist for emotional matters. If the amygdalae is severed from the rest of the brain, the result is a striking inability to gauge the emotional significance of events; this condition is sometimes called “affective blindness.”

Here please indulge a digression by HM to one of the projects he did as a graduate student. It involved conducting surgeries and implanting electrodes into the amygdalae of rats. These rats were deprived of water for 24 hours and then given an opportunity to drink. An electric current was applied to the amygdalae of some rats when they drank the water. The control rats were not shocked. The following day, the rats that had been shocked refused to drink, whereas the control rats, of course, drank. If you find this study troublesome, so does HM. But it did provide definitive evidence regarding the role of the amygdalae.

A fellow human had his amygdalae surgically removed to control severe seizures. He became completely uninterested in people, preferring to sit in isolation with no human contact. Although perfectly capable of conversation, he no longer recognized close friends, relatives, or even his mother, and remained impassive in the face of their anguish at his indifference. Absent the amygdalae, all recognition of feeling as well as any feeling about feelings is lost. Life without the amygdalae is life stripped of personal meanings.

All passion depends on the amygdalae. Animals that have their amygdalae removed or severed lack fear and rage, lose the urge to compete or cooperate, and no longer have any sense of their place in their kind’s social order; emotion is blunted or absent. As the amygdalae were not destroyed in HM’s rats, the stimulated rats returned to normal.

Tears, an emotional signal unique to humans, are triggered by the amygdala and a nearby structure, the cingulate gyrus. Being held, stroked, or otherwise comforted soothes these same brain regions, and stops the sobbing. Absent amygdalae, there are no tears of sorrow to soothe.

Goleman writes, “the workings of the amygdala and its interplay with the neocortex are at the heart of emotional intelligence. When impulsive feeling overrides the rational—the newly discovered role for the amygdala is pivotal. Incoming signals from the senses let the amygdala scan every experience for trouble. This puts the amygdala in a powerful position in mental life, something like a psychological sentinel, challenging every situation, every perception, with but one question in mind, the most primitive: “Is this something I hate? That hurts me? Something I fear?” If so—if the moment at hand somehow draws a “Yes”—the amygdala reacts instantaneously, line a neural tripwire, telegraphing a message of crisis to all parts of the brain.”

“When it sounds an alarm, it sends urgent messages to every major part of the brain: it triggers the secretion of the body’s fight-or-flight hormones, mobilizes the centers for movement and activates the cardiovascular system, the muscles, and the gut. Other circuits from the amygdala signal the secretion of emergency dollops of the hormone norepinephrine to heighten the reactivity of key brain areas, including those that made the senses more alert, in effect setting the brain on edge. Additional signals from the amygdala tell the brainstem to fix the face in a fearful expression, freeze unrelated movements the muscles had underway, raise heart rate and blood pressure, slow breathing. Others rivet attention on the source of the fear, and prepare the muscles to react accordingly. Simultaneously, cortical memory systems are shuffled to retrieve any knowledge relevant to the emergency at hand, taking precedence over other strands of thought.”

The extensive web of neural connections of the amygdalae allows them, during an emotional emergency, to capture and drive much of the rest of the brain—including the rational mind.

Research by LeDoux showed that sensory signals from the eye or ear travel first in the brain to the thalamus, and then—across a single synapse—to the amygdala; a second signal from the thalamus is routed to the neocortex—the thinking brain. So the amygdala can respond before the neocortex, which mulls information though several levels of brain circuits before it fully perceives and finally initiates its more finely tailored response.

LeDoux concluded, “Anatomically the emotional system can act independently of the neocortex. Some emotional reactions and emotional memories can be formed without any conscious cognitive participation at all.” LeDoux conducted an experiment in which people acquired a preference for oddly shaped geometric figures that had been flashed at them so quickly that they had no conscious awareness of having seen them at all. Nevertheless, our cognitive unconscious will still have formed an opinion as to whether we like it or not, not just the identity of what we’ve seen. Goleman notes that “our emotions have a mind of their own, one which can hold view quite independently of our rational mind.”

© Douglas Griffith and healthymemory.wordpress.com, 2018. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

Our Two Minds

March 8, 2018

There are two fundamentally different ways of knowing to construct our mental life. The rational mind is the mode of comprehension of which we are typically conscious. It is more prominent in awareness, thoughtful, able to ponder and reflect. There is another system of knowing which is alongside it. It is the emotional mind. The emotional mind is impulsive and powerful, if sometime illogical. This emotional/rational dichotomy resembles the folk distinction between “heart” and “head.” Knowing something “in your heart” is a different order of conviction that is somehow a deeper kind of certainty than thinking with your rational mind. In “Emotional Intelligence” Goleman writes, “There is a steady gradient in the ratio of rational-to-emotional control over the mind; the more intense the feeling, the more dominant the emotional mind becomes and the more ineffectual the rational. This is an arrangement that seems to stem from eons of evolutionary advantage to having emotions and intuitions guide our instantaneous response in situations where our lives are in peril—and where pausing to think over what to do could cost us our lives.”

Goleman continues, “These two minds, the emotional and the rational, operate in tight harmony for the most part, intertwining their very different ways of knowing to guide us through the world. Ordinarily there is a balance between emotional and rational minds, with emotions feeding into and informing the operations of the rational mind, and the rational mind refining and sometimes vetoing the inputs of the emotions. Still, the emotional and rational minds are semi-independent faculties, each, as we shall see, reflecting the operation of distinct, but interconnected, circuitry in the brain.”

Most of the time these minds are well coordinated with feelings being essential to thought, and thoughts to feelings. However, when passions surge the balance tips: it is the emotional mind that captures the upper hand, swamping the rational mind.

To understand the potent hold of emotions on the thinking mind it is useful to understand how the brain evolved. Human brains, with their three pounds or so of cells and neural juices, are about triple the size of those in our nearest cousins in evolution, the nonhuman primates. Over millions of years of evolution, the brain has grown from the bottom up, with its higher centers developing as elaboration of lower, more ancient parts. The growth of the brain in the human embryo roughly retraces this evolutionary course.

The most primitive part of the brain for all species that have more than a minimal nervous system is the brainstem surrounding the top of the spinal cord. This root brain regulates basic life functions like breathing and the metabolism of the body’s other organs, as well as controlling stereotyped reactions and movements.

The emotional centers emerged from the brainstem. Millions of years later in evolution, from these emotional areas the thinking brain or “neocortex” evolved. The fact that the thinking brain grew from the emotional reveals much about the relationship of thought and feeling: there was an emotional brain long before there was a rational one.

New, key layers of the emotional brain came with the arrival of the first mammals. Because this part of the brain rings and borders the brainstem, it was called the ‘limbic’ system, from “limbus,” the Latin word for “ring.” This new neural territory added emotions proper to the brain’s repertoire. When we are in the grip of craving or fury, head-over-heels in love or recoiling in dread, it is the limbic system that has us in its grip.

The limbic system refined two powerful tools, learning and memory, as it evolved. These advances allows an animal to be much smarter in its choices for survival, and to fine-tune its responses to adapt to changing demands rather than having invariable and automatic reactions.

About 100 million years ago, the mammalian brain took a great growth spurt. Piled on top of the thin two-layered cortex-the regions that plan, comprehend what is sensed, coordinate movement—several new layers of brain cells were added to form the neocortex. In contrast to the ancient brain’s two-layered cortex, the neocortex offered an extraordinary intellectual edge.

Our neocortex, so much larger than in any other species, has added all that is distinctly human. It is the seat of thought; it contains the centers that put together and comprehend what the senses perceive. It adds to a feeling what we think about it—and allows us to have feelings about ideas, art, symbols, imaginings.

This new addition to the brain allowed the addition of nuance to emotional life. Limbic structures generate feelings of please and sexual desire. The addition of the neocortex and its connections to the limbic system allowed for the mother-child bond that is the basis of the family unit.

So the neocortex provided the basis for sophisticated interactions among humans.
However, problems can emerge when the neocortex loses the upper hand. Consider a nuclear war. Here it would be clear that the neocortex had lost the upper hand to the emotional mind. And it is possible that the neocortex justified the launching of a nuclear war and the extinction of homo sapiens. Such irony!

© Douglas Griffith and healthymemory.wordpress.com, 2018. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.