Rewire Your Brain: Think Your Way to a Better Life

particularly involved in the snowballing effect of fear and anxiety. 
The central nucleus links nonthreatening stimuli with presumably 
threatening stimuli. This is why you can associate a bridge with 
death or talking to a stranger with humiliation. 
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34 Rew i r e
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However, there is another part of the amygdala that can circum-
vent the central nucleus. It is called the
basal nucleus stria terminalis
(BNST) and is an action pathway. By taking action, you can activate 
the BNST and circumvent the central nucleus and its inappropriate 
linking of nonthreatening stimuli with legitimate stimuli. 
By taking action, you also activate the left frontal lobe, which 
can decrease the overreactivity of the amygdala. The right frontal 
lobe is often overactivated in people with anxiety disorders. The left 
frontal lobe is also more action - oriented, whereas the right frontal 
lobe is more passive and withdrawal - oriented. Furthermore, the left 
frontal lobe promotes positive emotions, whereas the right frontal 
lobe promotes more negative emotions. 
Thus, you have within you the capacity to turn off the fi ght - or -
fl ight response and the false alarms. The left PFC and the hip-
pocampus work together to tame the amygdala and shut down the 
HPA axis. Taking action and doing something constructive can shut 
down the feeling of being overwhelmed, which is generated by the 
overreactivity of the right frontal lobe.
Moderating Anxiety 
The brain is a high - energy consumer of glucose, which is its fuel. 
Although the brain accounts for merely 3 percent of a person ’ s body 
weight, it consumes 20 percent of the available fuel. Your brain can ’ t 
store fuel, however, so it has to “ pay as it goes. ” Since your brain is 
incredibly adaptive, it economizes its fuel resources. Thus, during a 
period of high stress, it shifts away from the analysis of the nuances of 
a situation to a singular and fi xed focus on the stressful situation at 
hand. You don ’ t sit back and speculate about the meaning of life when 
you are stressed. Instead, you devote all your energy to trying to fi gure 
out what action to take. Sometimes, however, this shift from the higher -
thinking parts of the brain to the automatic and refl exive parts of the 
brain can lead you to do something too quickly, without thinking. 
This is what happens when you are overwhelmed with anxiety. In 
an extreme situation, such as when you are having a panic attack, 
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35
you might rush off to an emergency room for treatment for a heart 
attack — not because you are actually having one, but because you 
think you are having one. 
Stress is a fact of life; it ’ s not something that you can or should 
totally avoid. Rather, it should be managed and used to accomplish 
your goals. If you try to escape all stress, when you encounter a mild 
stressor or even the threat of stress, you will feel extremely stressed. 
Some stress and anxiety actually serve as useful motivators. Without 
a little anxiety, you wouldn ’ t get to work on time, complete projects 
effi ciently, or drive within the speed limit. 
Mild stress is therefore useful, and it can be regulated, as Jane 
discovered. The brain needs a little stress in order to remember 
important events and situations; your job is to learn how to regulate 
the stress. A little stress helps to code memories. No stress means 
no activation, which means that you ’ re bored and inattentive, which 
in turn means that you won ’ t remember what you are experiencing. 
Too much stress, however, narrows your focus and is not helpful for 
learning. 
Jane rewired her brain by making use of a moderate degree of 
anxiety. She had already experienced feeling overwhelmed with too 
much anxiety, and she had done what she could to avoid public 
speaking. That avoidant behavior, ironically, simply increased her 
anxiety. 
Neuroscientifi c research has shown that a moderate degree of 
anxiety is optimal for neuroplasticity. Too much or too little anxiety is 
not useful in this regard. Thus, rather than shy away from anxiety, 
you should confront it and make it useful. Consider the following 
skiing analogy: Leaning back on your skis increases your chance of 
falling, but if you lean forward just a little, you ’ ll have more control 
of your skis — even when you are skiing down a very steep slope. 
Think of it this way: Being bored, overconfi dent, and lazy about 
studying for an exam prepares you to fail. Being panicked about it 
also serves you poorly. The balance between too much and too 
little anxiety is what ’ s best for learning and memory. This balance 
is referred to as “ the inverted
U
” (technically, it ’ s called the Yerkes -
Dobson curve). The inverted
U
means that moderate activation 
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36 Rew i r e
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(i.e., stress or anxiety) keeps your brain alert, generating the correct 
neurochemistry to allow your brain to thrive and promote neuroplas-
ticity and neurogenesis. 
The effi cient way to deal with stress is to strive toward a moderate 
path. When there is a moderate degree of stress, cortisol, CRF, and 
norepinephrine bind to the cell receptors that boost the excitatory 
neurotransmitter glutamate. When the glutamate activity in the hip-
pocampus is moderately increased, there is a corresponding increase 
in the fl ow of information and in the associated dynamics at the syn-
apse that is critical for neuroplasticity. The more often a message is 
sent along the same pathway, the more easily it will fi re the same 
signals and use less glutamate — making the cells fi re together so that 
they can wire together. 
The main point here is that you shouldn ’ t try to run away from stress 
and anxiety; you should learn to manage it. By managing it, you ’ ll 
promote a healthy, thriving brain that generates neuroplasticity.
Activating Your Parasympathetic 
Nervous System 
The autonomic nervous system has two parts: the sympathetic nervous 
system and the parasympathetic nervous system. The sympathetic 
nervous system excites you, and the parasympathetic nervous sys-
tem relaxes you. In extreme situations, the sympathetic nervous 
sys tem triggers the HPA axis and the fi ght - or - fl ight response. 
Just as there is a balance between the sympathetic and parasym-
pathetic nervous systems, there is a counterbalance to the fi ght - or -
fl ight response. Dubbed the
relaxation response
by Harvard professor 
Herbert Benson, it is your body ’ s parasympathetic nervous system 
in action. It helps to lower your heart rate, lower your metabolism, 
and slow your breathing rate.