In this article, we will explore how lifestyle and other factors affect the alarm central of the brain, the amygdala. We will also take a closer look at why it is important to have a strong functional connection between the frontal lobe and the amygdala and what you can do to strengthen this connection. In this way you will become better at calming the amygdala, the brain and yourself when facing stress.
Amygdala – The alarm center of the brain
The fire alarm has gone off. Everything is dark, it’s in the middle of the night and you have suddenly woken up. Now you fear that your home is on fire. As you quickly sit up in bed, you don’t smell smoke, but you can feel your heart beating fast and hard. You can probably also feel that your muscles are tense and your system on full alert.
At this moment, not just one alarm has gone off, but two. The first alarm is the fire alarm, and is designed to trigger another alarm, your amygdala.
This almond-shaped structure is the alarm center of your brain and plays a central role in situations such as the one described above. Although we do not know all of its functions, it is heavily involved in processing threatening and fearful stimuli.
The amygdala normally calms down when the threat is no longer present or when we realize that what was thought to be a threat is not a threat after all. A typical example would be when we hear someone running towards us from behind. For a moment we can interpret it as danger, but when we turn our heads and realize that it is only a jogger, both the pulse and the tension calm down.
Stress activates the amygdala and «shuts down» the frontal lobe
The rational part of the brain, the frontal lobe, has just informed the amygdala that the perceived danger is not a threat after all. This process happens automatically because there is usually a close and strong functional connection between the frontal lobe and the amygdala.
In a healthy, non-stressed brain, the frontal lobe exercises control over the amygdala and other more primitive brain structures, such as the striatum – involved in regulating habits, the hypothalamus – involved in basic passions such as appetite, sex drive and aggression, and the amygdala – important for regulating emotional reactions.
However, when we are exposed to stress, especially uncontrollable stress, fear and other frightening stimuli, important changes occur in the brain that weaken this «top-down regulation». Normally the frontal lobe exercises control over the more primitive brain centers. But under stress two important things happen in the brain:
- Norepinephrine and dopamine are secreted, causing the frontal lobe to lose its calming influence over the more primitive brain centers.
- Secondly, activity increases in the more «primitive» brain centres, such as e.g. the amygdala.
The consequence of this is that uncontrollable stress, fear and frightening stimuli make us less able to control ourselves, and we act more on impulses from the more primitive brain centers.
If you want to read in more detail about this reaction in the brain, I recommend the article «Neural circuits responsible for conscious self-control are highly vulnerable to even mild stress. When they shut down, primal impulses go unchecked and mental paralysis sets in«, by Dr. Amy Arnsten and colleagues. Her article also forms the starting point for the article that you are now already well into reading.
Symptoms of stress
How do you react to stress? The vast majority of people have experienced stress in one form or another. Under stress, the body reacts physically, mentally, cognitively and behaviorally. The reaction is also affected by the intensity and duration of stress.
Physical symptoms of stress
- Headache
- Stomach and digestive problems
- Muscle pain
- Fatigue and reduced energy
- Dizziness
- Reduced sleep
Mental symptoms of stress
- Anxiety
- Panic attack
- Depression
- PTSD
Cognitive symptoms of stress
Stress affects cognitive function in several ways and particularly affects the frontal lobe and hippocampus:
- Reduced memory
- Inability to focus and concentrate
- Reduced learning ability
- Difficulty making decisions
Behavioral changes due to stress
- Irritation
- Anger
- Aggression
- Impulsivity
- Reduced self-control
- More unhealthy lifestyle choices including unhealthy food, cigarettes, alcohol, etc.
Risk factors for an overactive amygdala
Some people have a more reactive amygdala that fires more easily or more intensely when exposed to stress, fear or frightening stimuli. There are several known risk factors for an overactive amygdala and weakened functional connection between the amygdala and the prefrontal cortex (frontal lobe):
Early traumatic experiences
Functional MRI examinations have shown that children in orphanages have a weaker functional connection between the frontal lobe amygdala. These children have a higher degree of emotional dysregulation (15). Researchers believe that a lack of love, empathy and other important nurturing factors that children need may explain these findings.
Chronic stress
Chronic stress appears to both expand the intricate network of connections between neurons in the deeper, more primitive brain centers and also weaken the frontal lobe, the rational part of the brain. This sets the person up to become more vulnerable when faced with acute stress, as described above. In other words, chronic stress causes us to «lose control» more easily in situations of acute stress (14). Some researchers believe that the ability to reverse the stress-related changes can disappear if the stress lasts too long or is too intense (14).
Mental disorders
Having anxiety, depression, PTSD, and even chronic pain is associated with impaired functional connectivity between the prefrontal cortex (frontal lobe) and the amygdala. But, as we’ll see later, several of the common treatments for these conditions can improve functional connectivity, that is, how well the prefrontal cortex communicates with the amygdala.
Sleep difficulties
Sleep and emotions influence each other. Reduced sleep can lead to a weaker functional connection between the prefrontal cortex and the amygdala and also increase the activity of the amygdala. This can lead to increased emotional dysregulation (2,3,4,5).
Studies have shown that when people sleep just 2-4 hours less than usual, there is increased anger, irritability and a reduced ability to deal with frustrating situations the next day. Functional MRI examinations showed that study participants who had reduced sleep had increased reactivity in the amygdala and weakened functional connection between the medial prefrontal cortex and the amygdala.
In another study, researchers investigated the extent to which REM sleep affects the reactivity of the amygdala. REM sleep is the stage of sleep where dreams usually take place and is a stage of sleep that is important for maintaining good mental health. The researchers found that the more consolidated REM sleep the participants had the night before, the less reactivation was seen in the amygdala the following day during an activity that stimulated the amygdala.
Strategies to strengthen the functional connection between the frontal lobe and the amygdala
1. Mild stress
While acute, uncontrollable stress tends to fire up the amygdala and weaken the connection to the frontal lobe, studies have shown that young people who grow up with multiple, successful encounters with mild stress become better at coping with stress (14). It can be compared to lifting weights. If we want to strengthen a muscle, we need regular exposure to a sufficiently large load (stress). Trying to lift too heavy weights can damage the muscle, but exercising regularly with the right amount of weight will over time cause the muscle to grow and become stronger.
Practical tips: Be involved in activities that require some effort to perform. Many people get this through regular work, but many hobbies, sporting activities and activities at home can fall into this category.
2. Reduce stress and increase stress tolerance
Stress can be beneficial to a certain level, but if the duration is too long, or the intensity is too high, stress will break us down. Some people tolerate more stress than others, partly because they are more resistant to stress. If you are wondering whether you have good resistance to stress, you can examine this in more detail in this test .
How can stress be reduced most effectively? Popular stress reduction techniques are only part of the solution and are not always the most effective stress reduction strategy.
A. Address the root cause
As far as possible, try to deal with the cause of the stress. There are many types of stress, and different approaches are needed to succeed in effective stress management
- Social stress: Loneliness, challenging relationships, abuse
- Emotional stress: Fear, bitterness, frustration, sadness, anger
- Work-related stress: Time pressure, scarcity of resources, efficiency requirements, downsizing, unclear management, frequent changes.
- Physical stress: Noise, physical overload, pain, lack of sleep
- Financial stress: Lack of money, mortgage, unexpected expenses
Stress due to challenging relationships requires a different approach than financial stress. While communication and boundary setting can be central to the former type of stress, budgeting, help from a financial advisor or other professional help is often the best way to go about dealing with financial stress.
If bitterness is the cause of stress, forgiveness, letting go of bitterness and thoughts of revenge can help reduce stress. If you want to learn more about how to forgive other people more easily and the health effects of forgiveness, please read the article Forgiveness Health.
B. General stress-reducing activities and resistance to stress
In addition to addressing the cause of stress as much as possible, there are other things we can do to reduce symptoms of stress and build resilience to stress. They include simple strategies, including self-care:
- Regular physical activity, preferably outdoors with exposure to daylight and nature
- Be more in the moment, don’t live with worries about tomorrow and regrets about yesterday. Children and pets seem to be the experts at being present in the moment
- Remember to relax, rest and get enough sleep. Take time for daily rest and vacation. Also try to include weekly rest. Jews and Seventh-day Adventists set aside an entire day a week where they not only refrain from work, but take their minds off everyday tasks and stressors and focus on the most important and fundamental aspects of life in order to strengthen themselves physically, mentally and spiritually for the next week.
- Good social connections are essential for good mental health and can increase resistance to stress
- Good nutrition
- Peace of mind, clear conscience and outward focus (from oneself)
- Also try to include laughter, joy and a little innocent humor in your everyday life. Laughter has been shown to reduce stress within minutes.
3. Cognitive approaches dampen activation of the amygdala
Mental disorders, such as PTSD, anxiety and depression are associated with overactive amygdala and weakened functional connection with the prefrontal cortex. However, several of the common treatment methods for these conditions can «suppress» the activity in the amygdala and strengthen the connection to the frontal lobe. These include psychotherapy and cognitive behavioral therapy (22). In addition, regular physical activity, as described below, has a corresponding effect on the brain.
Studies have shown that cognitively demanding tasks also reduce activity in the amygdala (e.g. counting backwards). In one study (24), researchers performed functional MRI scans of participants with a fear of snakes and found reduced activation of the amygdala when shown images of snakes if the participants viewed the images under high cognitive load. This correlated with the participants having reduced perceived phobic fear when looking at snake pictures under high cognitive load.
A more common situation can be anxiety and nervousness before giving a speech or presentation to many people. Many people find that fear and anxiety are reduced when they start speaking because the cognitive load increases when they start the speech or presentation.
Practical tips: There are self-help books on cognitive behavioral strategies. However, if you have a medical condition as described above, it is recommended to get professional help from a therapist who can provide cognitive behavioral therapy or psychotherapy.
For cognitive tasks, try to divert your attention to a complex activity that requires you to use your brain actively, such as counting letters, making something, or playing a game.
4. Physical activity calms the mind
It is well known that regular physical activity can improve well-being and mental health. Physical activity can help reduce symptoms of stress, anxiety and depression.
In one study (10), researchers observed participants in functional MRI scans before and after physical activity. Participants walked or ran for 12 minutes. The researchers observed that:
- Physical activity had an anxiety-reducing effect
- The anxiety-reducing effect varied according to the participants’ general activity level. People who exercised more frequently experienced the greatest anxiety-reducing effect of a single exercise session.
- Running led to improved functional connectivity between the prefrontal cortex and other brain structures, including the amygdala
Practical tips: Exercising outdoors can increase the positive effect physical activity has on the amygdala. This is especially true if you exercise in nature, on a sunny day or in daylight. Read on for more information.
5. Nature suppresses the amygdala
Closely related to physical activity are nature experiences. We have probably all experienced the positive effect nature has on body and mind. Spending time in nature can reduce stress, improve mood and cognitive function and has also been shown to positively affect the amygdala.
In an interesting German study, the participants either walked for an hour in a forest, or for an hour in a busy street in Berlin (9). Before the trip and immediately after the trip, the participants underwent a functional MRI examination. The results showed that participants who walked for an hour in the forest had reduced activation of the amygdala in the face of stress, while participants who had walked in the busy city street did not experience the same effect.
Practical tips: Combine nature experience with physical activity
6. Light affects the amygdala
Several studies suggest that exposure to daylight, or blue light, strengthens the functional connection between the prefrontal cortex and the amygdala. In a study carried out at the University of Copenhagen (21), 30 healthy individuals received 30 minutes of light exposure every morning for three weeks. At the end of the three weeks, the researchers observed the following:
- The brains of the participants who received light therapy/exposure responded less to faces that showed fear or anger
- The brain was better able to control the fear center, the amygdala
- This effect on the brain was related to the light intensity. The more intense light the participants were exposed to, the greater the calming effect on the amygdala
The researchers concluded that light strengthens the communication between the frontal lobe and the amygdala. The prefrontal cortex appears to downregulate the activity of the amygdala, a part of the brain that plays a central role in our emotional response to our surroundings (7) Findings from other studies suggest that the calming effect light has on the amygdala comes fairly quickly after light exposure (8)
Practical tips: Feel free to combine physical activity, exposure to nature and daylight or sunlight
7. Sleep your way to to a calmer brain
As mentioned earlier in this post, sleep and emotions affect each other. Lack of sleep can lead to a weaker functional connection between the frontal lobe and the amygdala. Studies have shown that just 2-4 hours less sleep increases frustration, irritability and makes it more difficult to handle challenging situations the next day. So how do you get the sleep your body needs? If you struggle with sleep, try these practical tips :
- Plan your day to optimize your sleep. Wake up and go to bed at the same time every day. An hour +/- is acceptable. Calm down the last hour before bed.
- Have a sleeping environment that promotes sleep: Keep the bedroom dark, not too warm and with as little noise as possible
- Exposure to daylight early in the day, preferably combined with physical activity, results in better sleep in the evening
- Regular physical activity improves sleep, but for some it can worsen sleep if it is done late at night, or at the beginning of an exercise program.
- Avoid stimulants that can prevent you from falling asleep and staying asleep. Stimulants include nicotine and caffeine. Alcohol can help some people fall asleep, but alcohol reduces sleep quality and sleep structure and is not recommended as a sleep aid.
- Avoid blue light (screens) in the last hours before going to bed. It reduces the secretion of the sleep hormone melatonin.
Sleep problems are often caused by underlying psychological problems, such as anxiety, depression and stress. Address these underlying issues if they are present and sleep will usually improve as mental health improves.
To assess the severity of your sleep problems, you can take this test: Insomnia Severity Index test
If your sleep problems have lasted for several months, cognitive behavioral therapy for insomnia is one of the most recommended and effective non-drug strategies for improving sleep.
NHI.no offers a free self-help course for long-term sleep difficulties based on cognitive behavioral therapy for insomnia.
8. Good social connections strengthen the functional connection between the frontal lobe and the amygdala
As mentioned earlier in this post, studies have shown that a lack of a good parental relationship in childhood, or traumatic experiences early in life can reduce the functional connection between the frontal lobe and the amygdala and thus increase the risk of emotional dysregulation.
There is some documentation that increased (positive) social interaction and support can reduce activity in the limbic system including the amygdala and that this can be explained through greater activity in the prefrontal cortex (25).
Practical tips: Maintain good social relationships or connections and seek social support if you are faced with challenges that increase your stress level.
9. Belief in a loving God calms the amygdala
For believers, studies have shown that when people experience and worship a loving God it strengthens the frontal lobe and calms the limbic system including the amygdala (5).
Practical Tips: For more information on this topic, watch the video below by a Christian psychiatrist:
10. Nutritional factors that can affect the amygdala
A. Alcohol . Studies have shown that people who have developed alcohol dependence may have reduced functional connectivity between the frontal lobe and the amygdala, even several years after they have stopped drinking (11).
B. Caffeine . Caffeine stimulates the release of stress hormones and can cause symptoms of anxiety in some people. Studies suggest that one of the possible mechanisms may be increased activation of the fear center, the amygdala (17). Caffeine seems to be of little help in this area, especially if we are already stressed. Stress tends to make us focus on negative things, and caffeine has been shown to amplify this phenomenon and can increase negative emotions during stress (18).
This effect is possibly stronger among people who do not drink coffee regularly. There are mixed findings in studies on caffeine and stress activation.
Read more about how caffeine affects the brain in the article Good morning! …without caffeine?
C. Tryptophan . This essential amino acid is the building block of the neurotransmitter serotonin. Serotonin is involved in regulating mood, sleep, pain, appetite, and is also an important nerve signal in the nerve circuits that connect the frontal lobe with the amygdala. Functional MRI studies have shown that when tryptophan is excluded from the diet it affects the functional connection between the frontal lobe and the amygdala (13)
Practical tips: Try a month or two without caffeine and see if it makes a difference when you experience stress. Tryptophan-poor diets do not exist outside the «laboratory», so this is not a recommendation to supplement with tryptophan.
11. Deep breathing and relaxation exercises calm the mind
Functional MRI scans have shown (1) that being aware of breathing is an effective tool for reducing negative emotions. Researchers observed that paying attention to our breathing dampened amygdala reactivation and strengthened the functional connection between the frontal lobe and the amygdala. In addition, it increases activity in the parasympathetic part of the nervous system, which results in less amygdala activation.
Simple relaxation exercises can also help to reduce the stress response and an overactive amygdala (23).
Practical tips: When you are stressed and confronted with frightening stimuli, try to focus on breathing deeply. Feel free to take a double inhalation before exhaling deeply and slowly. Feel free to include a few minutes of relaxation exercises on busy and stressful days.
Conclusion
Although research into the functional connection between the frontal lobe and the amygdala is relatively limited, there is much evidence that how we treat the body and mind can affect the amygdala and how the frontal lobe and the amygdala communicate with each other.
A healthy lifestyle, including regular physical activity, enough sleep, good social relationships, avoiding stimulants, effective stress management, frequent exposure to nature and daylight may help keep the head «cool» and the heart «warm» in stressful situations.
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