Biology & Longevity
The Biology of Focus, Memory and Brain Fog
Attention is not one faculty. It is several separable networks, each with its own neurochemistry and its own failure modes.
August 21, 2026 · 6 min read · Novanta Research
Attention networks
Cognitive neuroscience distinguishes an alerting network, an orienting network and an executive control network. They rely on different transmitter systems — noradrenaline, acetylcholine and dopamine respectively — which is why a compound can improve one aspect of attention while leaving another untouched.
Working memory
Working memory depends on sustained firing in prefrontal circuits, and its relationship with dopamine follows an inverted-U curve: too little and the signal is unstable, too much and it becomes inflexible. Optimal is a narrow band, which is why more stimulation is not reliably better.
What 'brain fog' usually is
The term has no clinical definition. In practice it collects together sleep debt, systemic inflammation, thyroid and metabolic disturbance, dehydration, medication effects and mood disorders — all of which produce overlapping subjective symptoms.
That heterogeneity is precisely why research on cognitive compounds is difficult: the same complaint in two subjects can have entirely different physiology behind it.
Neurotrophic signalling
Brain-derived neurotrophic factor supports synaptic plasticity and is one of the most frequently measured endpoints in cognitive peptide studies, including work on Semax. Its expression responds to exercise, sleep and metabolic state as well, which makes it a noisy endpoint without tight controls.
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For laboratory and research use only. Not for human or veterinary consumption. Novanta Research is not a compounding pharmacy and nothing in this article is medical advice or a claim that any compound diagnoses, treats, cures or prevents any condition.