The nucleus basalis is the main neuromodulator of the basal forebrain and gives widespread cholinergic projections to the neocortex.

[3][1] The nucleus basalis is an essential part of the neuromodulatory system that controls behaviour by regulating arousal and attention.

[5] Acetylcholine affects the ability of brain cells to transmit information to one another, and also encourages neuronal plasticity, or learning.

Thus, damage to the basal forebrain can reduce the amount of acetylcholine in the brain and impair learning.

There have been studies on the use of deep brain stimulation to the nucleus basalis, in the treatment of dementia, and while giving some positive results trials are still being undertaken.