Posts Tagged ‘striatum’

Mind Over Matter

March 22, 2020

This post is based on an important book by Richard J. Davidson, Ph.D. with Sharon Begley, “The Emotional Life of Your Brain.” The title of this post is identical to the heading in an important book by Richard J. Davidson, Ph.D. with Sharon Begley. The remainder of the title is How Its Unique Patterns Affect the Way You Think, Feel and LIve—And How You Can Change Them.

Brain-imaging studies show that obsessive-compulsive disorder (OCD) is characterized by activity in two regions: the orbital frontal cortex, whose main function is to notice when something is amiss; and the striatum, which received input from the orbital frontal cortex as well as the amygdala. Together the orbital frontal cortex and striatum form what is called the worry circuit. In people with OCD it is buzzing with activity.

Rather than just drugging his patients (antidepressants including Prozac, Paxil, and Zoloft), neuropsychiatrist Jeffrey Schwartz got the idea of using a technique he employed in his own Buddhist meditation practice. Called mindfulness, or mindful awareness, it involves observing your own thoughts and feelings from the perspective of a nonjudgmental third party. In The Heart of Buddhist Meditation, the Buddhist monk Nyanaponika Thera described it as attending “just to the bare facts of a perception as presented either through the five physical senses or through the mind…without reacting to them by deep, speech or by mental comment.” In the case of his OCD patients, mindfulness meant learning to experience an OCD symptom without reacting emotionally, and learning to realize that the feeling that something is amiss is just the manifestation of overactivity in the OCD circuit. A patient would think, My OCD circuit is producing another obsessive thought. I know it is not real but just static from a faulty circuit. After mainly hours learning this technique, patients were better able to resist OCD messages, reporting that their disease no longer controlled them. Neuroimaging also showed that activity in the orbital frontal cortex, the core of the OCD circuit, had fallen dramatically compared with what it had been before mindfulness-based therapy. Thinking about their thoughts in a new way had altered patterns of brain activity.

Prof. Richardson writes, “This finding is crucial to my belief that we can similarly alter the patterns of brain activity underlying Emotional Style, so let me offer one more example of how mental training can accomplish this. Clinical depression is characterized by overactivity in specific regions of the frontal cortex, the seat of reasoning, logic, analysis, and higher thought, in particular regions associated with anticipation—perhaps the cause of the endless rumination that grips people suffering from depression. There is, in addition, often under activity in parts of the limbic system (the brain’s emotion center) associated with reward and pleasure. That would seem odd if you thought of depression as being marked primarily by an overwhelming sense of sadness, which presumably would show up as heightened activity in the limbic system. In fact, however, people with depression report that they experience what’s called flat affect—an inability to experience soaring flights of joy, certain, but also the absence of feelings such as curiosity or interest in the world.”

In the 1960s cognitive-behavior therapy use a form of mental training that focuses on teaching patients to respond to their emotions, thoughts, and behaviors in a healthy way and to reappraise dysfunctional thinking.

Scientists at the University of Toronto found that cognitive-behavior therapy has a powerful effect on the brain activity underlying depression. The therapy reduced activity in the frontal cortex and raised activity in the limbic system. Patients ruminated less and no longer felt emotionally dead inside. Their depression lifted, and in most cases stayed lifted: Rates of relapse with cognitive-behavior therapy are much lower than with medication, which in any case seems to be more effective than a placebo for anything but the most severe depression.

Prof. Davidson concludes this section as follows: “In short, the revolution in neuroplasticity has shown that the brain can change as a result of two distinct inputs. It can change as a result of the experiences we have in the world—how we move and behave and what sensory signals arrive in our cortex. The brain can also change in response to purely mental activity, ranging from meditation to cognitive-behavior therapy, with the result that activity in specific circuits can increase or decrease.”

Run Your Life on Autopilot

January 11, 2017

HM works from his iPAD.  This is the print title of an article by Anil Ananthaswamy in the October 1 issue of the New Scientist.  The healthy memory blog has stressed the importance of the unconscious mind and provided suggestions as to how to make use of your unconscious mind.  This and the following blog posts taken from this issue of the New Scientist elaborate on these ideas.

An enormous part of our day-to-day lives, driving, making coffee, or touch typing, happens without conscious thoughts.  Unlike many of the brain’s other unconscious habits, these skills had to be learned before the brain can automate them.  How it does this could potentially provide a method for us to think our way out of bad habits.

Ann Graybiel of the Massachusetts Institute of Technology and her colleagues  have shown that a region deep inside the brain called the striatum is key to habit formation.  When we undertake an action, the prefrontal cortex, which is involved in planning complex tasks, communicates with the striatum, which sends the necessary signals to enact the movement,  Over time, input from the prefrontal cortex fades, to be replaced by loops linking the striatum to the sensorimotor cortex.  The loops, together with the memory circuits, allow us to carry out the behavior without having to think about it.  Practice makes perfect and no thinking is required.  The obvious upside is that we no longer  need to focus our attention on a frequent task, the spare processing power can be used for other things.  Unfortunately, similar circuitry is involved in turning all kinds of behavior into habits, including thought patterns, and once any kind of behavior becomes a habit, it become less flexible and harder to interrupt.  This is fine for good habits, but when bad habits are ingrained, its equally hard to get rid of it.  You lose the moment of choice when we can decide not to do something.

Fortunately, even with the most ingrained habits, a small area of the prefrontal is kept online, in case we need to take alternative action.  This offers hope to any of us looking to break a bad habit and to those suffering from habit-related problems such as obsessive compulsive disorder and Tourette’s syndrome  — both of which are associated with abnormal activity in the striatum and its connections to other parts of the brain.  These circuits are potential targets for future drug treatments.  However, for now the best way to get a handle on bad habits is to become aware of them.  Then, focus all your attention on them and hope that it’s enough  to help the frontal regions resist the call of the autopilot.  An alternative approach is to teach ourselves a new habit that counters the bad one.

How Placebos Could Change Research and Practice

March 29, 2015

The title was on the cover of the April 2015 Monitor on Psychology of the American Psychological Association.  Inside the issue was an article by Stacy Lu, “Great expectations:  New research is leading to an understanding of how placebos work—findings that may lead to more effective treatments and better drug research.  Our understanding and attitudes towards placebos is advancing.

In one study neuroscience researcher Shaffer and his colleagues asked participants to apply a “powerful analgesic” on their hands and arms.  Then the researchers administered small bursts of heat where the cream had been applied.  The cream was actually petroleum jelly, but participants reported that the s-called powerful cream protected them from feeling as much of a burn  as a control cream.  Even after the researchers showed them that the active cream was just petroleum jelly, it made little difference.  The participants still reported less pain from the heat when they were re-tested versus the control cream (The Journal of Pain, 2015).

Today scientists are studying  placebos as a psychobiological  phenomenon and the placebo response as a potentially important part of the success of many medical treatments.  Psychological assessments, brain scans, and genotyping are used  to understand better how placebo responses work and to identify who may be most likely to respond to them.  Placebos are similar to cognitive therapies in that they tap into people’s beliefs that there’s hope and that they will get better.

A meta-analysis of 25 neuroimaging studies of pain and placebos conducted by Wager and Atlas of the National Center for Complementary and Integrative Health (NCCIH) found that people who took placebos and expected have reduced pain had less activity in brain regions associated with pain processing, including the dorsal anterior cingulate, thamalus, and insula (Handbook of Experimental Pharmacology, 2014).

Research suggests that placebos have the greater effect in neural systems involved with processing reward seeking, motivation, and emotion.  Placebos seem to work especially well in patients with depression, Parkinson’s disease, and pain.  All three conditions involve the neurotransmitter dopamine.  These are also areas where people can consciously monitor their own treatment results.

In a study of patients with Parkinson’s disease Wager and colleagues found that simply expecting medication altered brain activity in the striatum and ventromedial prefrontal cortex in brain areas associated with reward learning in ways similar to actual dopaminergic medication (Nature Neuroscience, 2014).

In another study of people with migraines, placebos elicited a response without any verbal cue to effectiveness,   Slavenka Kam-Hansen and colleagues openly labeled placebo pills for some patients who reported as much pain relief as those who also got a placebo but had been told that they’d received real medication. (Science Translational Medicine, 2014).

Genetics research has found that participants with a specific genotype related to having more dopamine in the prefrontal cortex reported having a larger effect from a placebo  treatment  than participants with a genotype that produces less dopamine in the prefrontal cortex (PLOS ONE, 2012).

Children seem to respond especially well to placebos.  In one study their placebo response was 5.6 that of adults (The Journal of Pain, 2014).

Patients are interested and enthusiastic about placebo  treatments.  They are pleased to discover that they can contribute to their own healing.

Organizing Our Homes

December 7, 2014

Organizing Our Homes is the title of a chapter in Daniel J. Levitin’s book The Organized Mind. His subtitle for this chapter is “Where Things Can Start to Get Better”.   I am probably more in need of the information in this chapter than any of the healthymemory blog’s readers. But my problem is primarily motivational in that although I know the systems for effective organization, but I don’t implement them. Unfortunately, Levitin does not provide any motivational advice. Perhaps one day some disaster will occur that will provide me the motivation for implementing these practices.. One practice I do strictly follow is to keep my most important items in the same place. Individual items might be in separate places, but each important item is always kept in the same place. When I travel or move to a new place, one of my first actions is to decide where these important items go. If I want to be sure to remember to take my umbrella on a given day, I place it in a conspicuous place on my way out. However, even this precautionary measure has sometimes failed.

Levitin uses the four system for remembering important items. Every time he leaves the house he checks that he has four things: keys, wallet, phone, and glasses. The number four is significant as we are constrained by the number of items we can hold in our working or short term memories. George Miller’s original number was 7 plus or minus 2. However, that number has shrunk over the years, and is currently down to four. If he needs to remember something else before leaving the house, say to remember to buy mild on the way home, he will either place an empty mild carton on the seat beside him in his car, or he’ll place the carton in his backpack. Of course a note will be do, but some reminder is needed so the note will not be forgotten.

The problem of misplacing items and being unable to find them is ubiquitous. Levitin writes about Magnus Carlsen the number one rated chess in the world when he was 23. He can keep ten games going on at once in memory without looking at the board, but he says, “I forget all kinds of other stuff. I regularly lose my credit cards, my mobile phones,keys, and so on. Actually all of these memory failures are the result of failing to attend where the object is being placed. Moreover, enough attention needs to be devoted to the object so that the location of the object will later be remembered.

Levitin also discusses the concept of affordances. The term is used in the sense that the environment affords you to do something. One of the best examples of affordances are the plates or handles that are placed on doors. The plate affords the pushing of the door. The handle affords the pulling of the door. Unfortunately, these affordances are frequently misplaced. For example, you try to push a door that has a handle on it and it does not move. Once I was following a lady out of the building. She tried to push a handle and then apologizes for being stupid when it did not move. I explained to her that she was not the stupid. Instead it was the architect of the building or the installer of the door who was stupid. The renowned psychologist B.F. Skinner elaborated on these affordances. If you have letters to mail put them near your car keys or house keys so that when you leave the house their affordance reminds you to take them. The goal is to off-load the information from your brain into the environment by using the environment itself to remind you of what needs to be done. So the idea is to use the environent as a type of transactive memory.

To people who argue that they are not detailed-oriented, that they are a creative person or some such. Levitin provides some good examples from Joni Mitchell, Stephen Stills, John Lennon. Michael Jackson even had a person on his staff titled the chief archivist. Organization was essential to these creative people.

Levitin provides these three general rules of organization..

      1. A mislabeled item or location is worse than an unlabeled item.

      2. If there is an existing standard, use it.

      3. Don’t keep what you can’t use.

Personally I have much difficulty with this third rule.

Levitin devotes a section to the digital home where he recommends organizing by devices, where special devices perform special tasks. He has another section on the storage of information in different types of media and the advantages and disadvantages of each. He notes, rather discouragingly, that digital files are rarely readable for more than ten years. He notes that within the spreadsheet Excel you can link any entry in a cell to a document on the computer. So financial documents for a given year could be in a PDF file linked to a cell in a spreadsheet.

Above all, do not multi-task while you are organizing. He notes that just having the opportunity to multitask is detrimental to cognition. Glenn Wilson of Gresham College in London calls it infomania He has done research that demonstrated that being in a situation where you are trying to concentrate on a task, and an e-mail is sitting unread in the inbox can reduce the effective by 10 points. He has also shown that cognitive losses from multitasking are even greater than the cognitive losses from pot smoking.

A neuroscientist at Stanford, Russ Poldrack, found that learning information while multitasking causes the new information to go to the wrong part of the brain. The information goes into the striatum, a region specialized for storing new procedures and skills, not facts and ideas. Absent the distraction of TV the information goes into the hippocampus, where it is organized and categorized in a number of ways so that it is easier to retrieve.

Moreover, there are metabolic costs to switching attention. Shifting the brain from one activity to another causes the prefrontal cortex and striatum to burn up oxygenated glucose, the same fuel needed to stay on task. The rapid, continual shifting when we multitask causes the brain to burn through fuel so quickly that we feel exhausted and disoriented after even a short time. We’ve literally depleted the nutrients in our brain compromisisng both cognitive and physical performance. In addition, repeated task switching leads to anxiety , which raises levels of the stress hormone cortisol in the brain which in turn can lead to aggressive and compulsive behavior. In contrast, staing on task is controlled by the anterior cingulate and the striatum ,and once we engage the central executive mode, staying in that state uses less energy than multitasking and actually reduces the brain’s need for glucose. .