Webb Therapy Uncategorized The ‘Triune Brain’ theory by Neuroscientist Paul MacLean — an evolutionary perspective

The ‘Triune Brain’ theory by Neuroscientist Paul MacLean — an evolutionary perspective

The Concept of the "Triune Brain"

In the 1960s, American neuroscientist Paul MacLean formulated the ‘Triune Brain’ model, which is based on the division of the human brain into three distinct regions. MacLean’s model suggests the human brain is organized into a hierarchy, which itself is based on an evolutionary view of brain development. The three regions are as follows:

  1. Reptilian or Primal Brain (Basal Ganglia)
  2. Paleomammalian or Emotional Brain (Limbic System)
  3. Neomammalian or Rational Brain (Neocortex)

At the most basic level, the brainstem (Primal Brain) helps us identify familiar and unfamiliar things. Familiar things are usually seen as safe and preferable, while unfamiliar things are treated with suspicion until we have assessed them and the context in which they appear. For this reason, designers, advertisers, and anyone else involved in selling products tend to use familiarity as a means of evoking pleasant emotions.

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Thinking About Change? How Motivational Interviewing Can HelpThinking About Change? How Motivational Interviewing Can Help

If you’ve ever found yourself thinking “Part of me wants to change… but part of me’s not sure”, you’re not alone. That back-and-forth, weighing things up—“Should I? Shouldn’t I?”—is a normal part of how people process big (and small) decisions. In counselling, this is called ambivalence, and rather than seeing it as a barrier, Motivational Interviewing (MI) treats it as a starting point for meaningful conversations.

What Is Motivational Interviewing?

Motivational Interviewing is a counselling approach that helps people explore their own reasons for change, without pressure or judgment. It’s a respectful, supportive way of helping you work through the push-pull that often comes with making decisions. You’re in the driver’s seat—we’re just here to help you navigate.

You might hear MI described in different ways:

In simple terms:
“MI is a collaborative conversation style that helps strengthen your own motivation and commitment to change.”

In practice:
“MI is about helping you make sense of mixed feelings and explore what’s right for you—based on your values, your goals, and your life.”

MI isn’t about telling you what to do. It’s about listening deeply, asking thoughtful questions, and helping you make sense of where you’re at—and where you might want to go.

Why It’s Not Just a Quick Fix

While MI can be used in short sessions, the research shows it works best when there’s time to really explore your thinking. In studies where people had just one 15-minute session, the outcomes were decent. But when they had more time—say, several sessions of an hour—the results were much stronger. That’s probably because real change often takes time, reflection, and a bit of back-and-forth.

MI originally started in the health world—helping people reduce alcohol use, manage weight, or improve their health. More recently, it’s been used to address things like vaccine hesitancy. But MI isn’t just for health issues. It can also help with things like relationship struggles, career decisions, or anything where you might feel stuck or unsure.

Ambivalence Is Normal

Let’s say you’re thinking about quitting smoking, leaving a relationship, or starting something new. You might feel torn—part of you is ready, and another part isn’t. That’s ambivalence.

MI offers tools to help with this, including something called the Decisional Balance, which simply helps you look at both sides: What are the good things about staying the same? What are the reasons you might want to change?

But here’s the thing—MI isn’t about pushing you toward a particular outcome. If you’re trying to make a decision where there’s no obvious “right” answer—like whether to stay in a relationship—the counsellor stays neutral. They don’t steer you in one direction. Instead, they help you explore what matters to you.

Talking Your Way Toward Change

One of the interesting things about MI is how it pays attention to the language you use when you talk about change.

Some of the things people say when they’re starting to think about change include:

  • “I probably should cut down…”
  • “I’d like to feel better about this…”
  • “I don’t know if I can keep doing this…”

These kinds of statements are called change talk—and they’re actually signs that something inside you is shifting. MI aims to gently encourage and grow this kind of talk, because research shows that the more someone talks about change, the more likely they are to act on it.

There’s also sustain talk, which sounds like:

  • “I don’t smoke that much…”
  • “I know I should, but it helps me relax.”
  • “Now’s not really the right time.”

Both are normal. In MI, there’s no need to rush. Instead, the focus is on listening to both sides of you—and helping you get clearer about what you want to do next.

Getting Skilled Support

Like any professional approach, MI works best when the counsellor is trained and skilled in using it. Some practitioners have their sessions reviewed (with consent) by independent experts to make sure the spirit and skills of MI are being used well.

If you ever hear a practitioner say they “do MI”, you can ask what that looks like. The most effective use of MI goes beyond just asking open-ended questions or offering summaries—it’s about how your counsellor supports you in finding your own reasons for change.

What a Session Might Involve

Motivational Interviewing tends to follow a flexible process with four key parts:

  1. Engaging – Building trust and understanding
  2. Focusing – Exploring what matters most to you
  3. Evoking – Drawing out your own reasons for change
  4. Planning – When you’re ready, looking at possible next steps

You don’t have to go through these in a straight line. Some days you might focus on one step, then circle back to another later. It’s all guided by you—your pace, your readiness, your goals.


In Summary

If you’re feeling uncertain about making a change—or you’ve been thinking about it for a while but haven’t quite landed on what to do—Motivational Interviewing could be a really helpful way to explore things.

It’s not about being told what to do, and it’s not about “fixing” you. It’s a respectful, evidence-based approach that helps people work through their own ambivalence, connect with what matters to them, and move toward change when they’re ready.

Change doesn’t have to be instant. And it doesn’t have to be perfect. But it can start with a conversation.

How does methamphetamine (aka. crystal meth) affect the brain?How does methamphetamine (aka. crystal meth) affect the brain?

To answer that question, I’ll need to explain a part of the brain called the Limbic System.

Within the brain there is a set of structures called the limbic system. There are several important structures within the limbic system: the amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, and cingulate gyrus. The limbic system is among the oldest parts of the brain in evolutionary terms. It’s not just found in humans and other mammals, but also fish, amphibians, and reptiles.

The limbic system is the part of the brain involved in our behavioural and emotional responses, especially when it comes to behaviours we need for survival: feeding, reproduction and caring for our young, and fight or flight responses (https://qbi.uq.edu.au/brain/brain-anatomy/limbic-system).

The limbic system contains the brain’s reward circuit or pathway. The reward circuit links together several brain structures that control and regulate our ability to feel pleasure (or “reward”). The sensation of pleasure or reward motivates us to repeat behaviours. When the reward circuit is activated, each individual neuron (nerve cell) in the circuit relays electrical and chemical signals.

In a healthy world without addictive manufactured drugs, humans survive and thrive when they are rewarded for certain behaviours (cleaning, hard work, sex, eating, achieving goals etc), hence evolution has provided us with this feel-good chemical so that we will repeat pleasurable behaviours.

There is a gap between neurons called the synapse. Neurons communicate with each other by sending an electro-chemical signal from one neuron (pre-synaptic neuron) to the next (post-synaptic neuron). In the reward circuit, neurons release several neurotransmitters (chemical messengers). One of these is called dopamine. Released dopamine molecules travel across the synapse and link up with proteins called dopamine receptors on the surface of the post-synaptic neuron (the receiving nerve cell). When the dopamine binds to the dopamine receptor, it causes proteins attached to the interior part of the post-synaptic neuron to carry the signal onward within the cell. Some dopamine will re-enter the pre-synaptic nerve cell via dopamine transporters, and it can be re-released.

When a reward is encountered, the pre-synaptic nerve cell (neuron) releases a large amount of dopamine in a rapid burst. Dopamine transporters will remove “excessive” amounts of dopamine naturally within the limbic system. Dopamine surges like this help the brain to learn and adapt to a complex social and physical world.

Drugs like methamphetamine (a stimulant drug) are able to “hijack” this process contributing to behaviours which can be considered unnatural or potentially dysfunctional. A range of consequences can follow.

When someone uses methamphetamine, the drug quickly enters the brain, depending on how the drug is administered. Nevertheless, meth or ice is quick acting. Meth blocks the re-entry of dopamine back into the pre-synaptic neuron – which is not what happens naturally. This is also what cocaine does to the brain. However, unlike cocaine, higher doses of meth increase the release of dopamine from the presynaptic neuron leading to a significantly greater amount of dopamine within the synapse. Higher doses of cocaine will not release “more dopamine” from the pre-synaptic neuron like meth does. This is why after about 30 minutes or so, people who use cocaine will need more to maintain the high.

Dopamine gets trapped in the synapse (space between nerve cells) because the meth (like cocaine) prevents “transporters” from removing it back into the cell it came from. The postsynaptic cell is activated to dangerously high levels as it absorbs so much dopamine over a long period of time. The person using meth experiences powerful feelings of euphoria, increased energy, wakefulness, physical activity, and a decreased appetite.

When an unnatural amount of dopamine floods the limbic system like this over a long period of time, without reabsorption, then our brain is not replenished with dopamine, hence people who use meth often (even on a single occasion) may feel unmotivated, depressed, joyless, and/or pointlessness when they stop using. Figuratively speaking, the brain is “empty” or low on dopamine fuel, and it will take time to for dopamine to return to baseline levels and replenish itself. This may motivate the user to seek more methamphetamine to return to “normal”.

Methamphetamine can also cause a variety of cardiovascular problems, including rapid heart rate, irregular heartbeat, and increased blood pressure. Hyperthermia (elevated body temperature) and convulsions may occur with methamphetamine overdose, and if not treated immediately, can result in death (What are the immediate (short-term) effects of methamphetamine misuse? | National Institute on Drug Abuse (NIDA) (nih.gov))

SIGNS OF SUBSTANCE MISUSE OR ADDICTION

  • Finding it difficult to meet responsibilities.
  • Withdrawing from activities or not enjoying activities that used to provide satisfaction e.g. work, family, hobbies, sports, socialising.
  • Taking part in more dangerous or risky behaviours e.g., drink driving, unprotected sex, using dirty needles, criminal behaviour.
  • Behaviour changes e.g., stealing, exhibiting violence behaviour toward others.
  • Conflict with partner/family/friends, losing friends.
  • Experiencing signs of depression, anxiety, paranoia, or psychosis.
  • Needing more substance to experience the same effects
  • Cravings and urges to use the substance and symptoms of withdrawal when not using the substance.
  • Having difficulty reducing or stopping substance use.
  • Regretting behaviours while under the influence and continuing to use again.

(Substance abuse, misuse and addiction | Lifeline Australia | 13 11 14)