the human brain is the central organ of the nervous system

human brain nervous system cognition emotions memory intelligence neurons synapses cerebrum cerebellum brainstem consciousness perception learning neurotransmitters neurobiology function sensory processing motor control waves reflexes thinking creativity attention mental health neurodegenerative diseases parkinson 039 disease stroke injury emotional regulation hippocampus amygdala prefrontal cortex neural circuits bloodbrain barrier plasticity development neurogenesis research disorders sleep structure connections scans mri activity cognitive functions