Tag Archives for " Limbic System "

From Reward to Slavery – The Stages of Addiction

From Reward to Slavery, the Stages of Addiction

The word “addiction” is derived from a Latin term for “enslaved by” or “bound to.” Anyone who has struggled to overcome an addiction — or has tried to help someone else to do so — understands why. In the first chapter, addiction was presented as a continuum, as there are degrees of severity, it’s not an on-or-off condition. In chapter 2, we saw that the criteria become more severe as the disorder progresses. In this section, we are going to look at addiction from a new direction — from the standpoint of neuroplasticity. If a substantial part of addiction is learned behavior, how and why does it happen, and most importantly, how can we go about reversing or countermanding the learned part of the process.

Earlier, we learned that there are three phases, or stages of normal learning. the acquisition phase, where we gather sensory data and decide what to do with it; the declarative phase, or memory we use in conscious decision-making; and finally, working or habit memory, which governs actions we take without the intervention or collaboration of our conscious mind. Although behavioral characteristics vary with the particular drug, the process of addiction can also be divided into three distinct stages, which correspond to the three memory phases.[i]

All drugs of abuse trigger the limbic system by stimulating the release of dopamine in the neurons.[ii],[iii] This stimulation focuses our attention, gives us pleasure, and causes our brain circuitry to record the entire experience, so it can be repeated in the future. Because it’s the limbic system that’s involved, the message is powerful, and even the early experiences are encoded quite strongly.[iv] The dopamine release triggered by drug use is two to ten times stronger and of much longer duration than that of any normal biological rewards.[v] For such rewards, (eating, sex, etc.) once the person has learned the most efficient behavior to obtain a reward, dopamine release to facilitate further learning is not necessary and does not occur.[vi] Drug use, on the other hand, always produces a dopamine release if a sufficient amount is taken, even in chronic users.[vii]Continue reading

Neuroplasticity and Addiction

In February, I had the opportunity to address a group here in Ajijic on the topic of neuroplasticity, and how it applies to addiction and an ageing population. The video is in three segments, and totals about 40 minutes in length. The talk was given on the 19th of February, following three weeks that were unseasonably chilly here, and we even had a little rain, if anyone is curious about the references to the weather in the first part of the talk.

The venue was our Sunday morning “Open Circle” gathering. Each week we have a speaker on a different topic, typically someone local with specialized expertise in a certain area. They let me speak anyway, and, in fact, they let me come back on April 22nd to talk about Rational Emotive Behavior Therapy, which I’ll be posting here in a week or so.

Enjoy the video! When you reach the end of the first segment, click on the little white box to start the second segment. Rinse, repeat.

The Neuroplastic Learning Process

The stimulus-driven learning process

We forge long-term memories, and learn nearly everything we retain by strengthening neural connections through repetition, and sometimes trauma or reward. Certain events can imprint permanent memories, simply by their magnitude, and their effects upon our lives and our emotions. Events such as Pearl Harbor, the assassination of President Kennedy, and the horror of 9/11 evoke strong associations, and any of us who lived through them remember where we were and what we were doing when we first heard about them. Few of us, however, could recall what we did on the preceding day. We are all familiar with that kind of memory imprinting and recall, but what about the normal, everyday kinds of things we try to remember – and sometimes fail. How does this neuroplasticity really work, and, most importantly, do we have any control over it?

The first step in memory formation is called “encoding,” which is a biological process, rooted in the senses, that begins with perception. As an example, think of meeting your first “crush.” When you met him or her, your visual system registered things like their physical appearance, the color of their eyes, the tilt of their head, and their smile. Your auditory system may have recorded the sound of their laughter. You may have experienced the smell of their after-shave or perfume. You may have even felt the touch of their hand upon your arm. These separate sensations traveled along neural pathways from different regions to a portion of your brain stem called the hippocampus, where they were integrated, as they occurred, and became one single experience – your experience of that specific person.

Imaging studies indicate that the hippocampus, along with another part of our brain, called the frontal cortex is responsible for analyzing these various sensory inputs and deciding if they’re worth remembering or not. If they are, they become part of our long-term memory. If not, they stay in short-term memory for a brief time, and are then forgotten. Do we have any control over what information is retained in long-term memory? Yes, we absolutely do, there are a couple of tools we can use to train our minds to commit information to long-term memory, one is repetition, and the other is mindfulness.Continue reading