Cognition

Cognition is the collection of mental processes by which the brain acquires, stores, retrieves and uses information, including attention, memory, language, reasoning and planning.

These abilities depend on networks spanning the prefrontal cortex, hippocampus, parietal and temporal lobes, and on chemical messengers such as acetylcholine, dopamine and glutamate. Cognition changes across life, improving through childhood, peaking in early adulthood for speed-based skills, and declining gradually in processing speed and recall with normal aging while vocabulary and accumulated knowledge remain stable. Sleep, mood, pain, medications and alcohol all affect it in the short term.

Clinicians measure cognition with brief screens such as the Montreal Cognitive Assessment and with longer neuropsychological batteries that test specific domains. Marked or progressive decline is evaluated for dementia, while temporary difficulty is often described as brain fog. In aging dogs and cats a similar syndrome, cognitive dysfunction, shows as disorientation and disrupted sleep. THC is known to impair attention and memory while active; CBD has been studied for cognitive effects in early research with no established conclusions.