Adjusting the levels of neurotransmitters by regulating the timing of cortisol and catecholamine during the day can lead to optimal brain performance, with early daylight hours being ideal for activities that require high levels of dopamine, norepinephrine and epinephrine and later daytime hours being ideal for lower levels of these hormones and higher levels of serotonin and GABA. Certain adaptogens, such as dark leafy greens and ashwagandha, can buffer stress response and optimize brain performance.