That same circuitry is active in your brain today in the amygdala, hippocampus, and related structures. It's hard-wired to scan for the bad, and when it inevitably finds negative things, they're both stored immediately and made available for rapid recall. In contrast, positive experiences (short of million dollar moments) are usually registered through standard memory systems, and thus need to be held in conscious awareness 10 to 20 seconds for them to really sink in.
In sum, your brain is like Velcro for negative experiences and Teflon for positive ones.
In the moment, this built-in bias puts a negative spin on the world and intensifies our stress and reactivity. Over time, these experiences build up in what's called "implicit memory," casting a glum shadow over mood and outlook, and darkening one's interior landscape. Yes, these hard-wired inclinations have been evolutionarily successful, but Mother Nature cares about grandchildren, not about dukkha.
In terms of Buddhist practice, the brain's negativity bias feeds all the hindrances, and it saps motivation for right effort. It also undermines bhavana -- the cultivation of wholesome qualities -- by downplaying good lessons and experiences, by undermining their storage, and by making it harder to recollect positive states of mind so we can find our way back to them.
You can overcome this innate tilt toward the negative by deliberately enhancing the way your brain forms implicit memories:
(1) Help positive events become positive experiences:
- Pay extra attention to the good things in the world and in yourself. For example, notice things that go well, or people who treat you kindly, or your success at something. As we know, it is ignorance, fundamentally, that leads to suffering, and not seeing the good that is actually present is a kind of ignorance.
- As a mindfulness practice, focus on the sensations and the feelings in your positive experiences since they are the pathway to emotional memory.
- Deliberately create positive experiences for yourself. Examples include acts of generosity, evoking compassion, or recalling a time when you were happy.
(2) Savor the experience as a kind of concentration practice; keep your attention on it for many seconds while letting it fill your body and mind.
(3) Sense that the experience is soaking into you, registering deeply in emotional memory. You could imagine that it's sinking into your chest and back and brainstem, or imagine a treasure chest in your heart.
These three steps usually take half a minute or less, and with practice, you'll get even faster. Every day, there are many opportunities for noticing and absorbing good experiences. Any single instance won't make a big difference, but as the days and weeks add up, the mounting pile of positive implicit memories will provide more resources for coping -- and practice -- and brighten your inner landscape.
Because "neurons that fire together, wire together," momentary states become enduring traits. These traits then become the causes of more wholesome states, which nourish your traits further in a positive cycle. To paraphrase Mathieu Ricard: If you take care of the minutes, the hours -- and the days and years -- will take care of themselves.
How Brain Science Can Support Practice
To be sure, Western science is not necessary to fulfill the path of awakening set forth by the Buddha. But the emerging map of the mind and the brain can support practice in numerous ways.
First, knowing more about the brain/mind deepens conviction (faith) -- one of the factors of enlightenment -- since scientific developments keep re-confirming the dharma. For example, researchers have found that the activities of "self" are scattered throughout the brain, constructed from multiple sub-systems, and activated by many prior causes. There is no coherent, stable, independent self looking out through your eyes; in a neurological sense, self is truly empty. For many Westerners, science is the benchmark authority for what is true, and its harmony with Buddhism reduces the hindrance of doubt.
Second, neuropsychology can explain why traditional practices work, and help you emphasize their key elements. For instance, the rapture and joy that are traditional factors of meditative absorption, involve high levels of the neurotransmitter, dopamine. Your brain also uses pulses of dopamine to open the neuronal gate that allows new material into the field of attention. But when you're full of rapture and joy, any new surges of dopamine make little difference since their levels are already near their maximum. As a result, the gate of attention stays closed, and you remain focused on the breath. Happiness is truly skillful means!